bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Mineral Nitrogen and Glucose Application on Temperature Sensitivity (Q10) of Mineralization of Soil Organic Matter
Authors: Matvienko А. I. , Gromova M. S. , Menyailo O. V.
Published: April 2024

The temperature sensitivity of C mineralization in the soils of two ecosystems was studied: a forest glade and a dead cover pine forest. It is shown that the temperature sensitivity is higher in the forest glade than in the pine forest and increases down the soil profile. Soil depth was found to be the strongest determinant of Q10 variation. The application of nitrogen (NH4NO3) increased Q10 in the upper soil horizons, and the application of glucose, on the contrary, decreased Q10 in both ecosystems, the effect of glucose was most pronounced in the lower horizons. The co-application of glucose and nitrogen affected Q10 as well as the addition of glucose alone, indicating that the availability of a readily degradable substrate is a stronger factor influencing temperature sensitivity than nitrogen. The data obtained make it possible to predict the change in the contribution of the heterotrophic component of CO2 emission from soils during global warming and an increase in the influx of living root inputs, phytodetritus and exogenous nitrogen into the soil.
Glyphosate Effects on Some Characteristics of Biological Activity and Phytotoxicity of Sod-Podzolic Soil in a Short-Term Model Experiment
Authors: Kostina N. V. , Gorlenko M. V. , Mazurov K. A. , Filippova O. I. , Plyushchenko I. V. , Rodin I. A. , Kulikova N. A.
Published: April 2024

In a model laboratory experiment on infertile arable soil with low biological activity, it was found that the introduction of glyphosate leads to a short-term change in the intensity of the main processes of microbial transformation of nitrogen in the soil. When incubating soil with glyphosate at the maximum recommended dose of 8 l/ha for 22 days, there is an increase in nitrogen-fixing and denitrifying activity by 30–80% and 300% and a decrease in the nitrification process by 20–40%. The effects are of a short-term nature and do not reflect the entire complex of ongoing microbiological processes: no effect of glyphosate was detected on the emission of CO2, which is an integral indicator of biological activity. At the end of incubation in the soil with the introduced glyphosate, there was an increase in the number of bacteria by 40% and a decrease in the number of micromycetes by 70%. In general, under the selected conditions, the introduction of glyphosate led to a marked deterioration in the biological activity of the soil. By the method of multisubstrate testing, it was shown that under the action of the herbicide there is an increase in the value of the coefficient of rank diversity of the consumption spectra of substrates d, accompanied by a decrease in the specific metabolic work W and the integral vitality index G. It was shown for the first time that when glyphosate is introduced into soil with low biological activity and availability of phosphorus and the herbicide is degraded along the sarcosine pathway with a break in the C–P bond, excluding the formation of toxic metabolites, there is a pronounced negative effect of glyphosate on soil microorganisms, which leads to inhibition of wheat plant growth.
Abundance and Diversity of Microorganisms in Soils and Associated Substrates (Leaf Litter and “Suspended Soil”) in Some Nature Reserves of Vietnam
Authors: Kniazeva A. V. , Lysak L. V. , Lapygina E. V. , Aleksandrova A. V.
Published: April 2024

A comprehensive study has been carried out, and a quantitative and qualitative characteristic of the soil prokaryotic community of zonal Ferralsol and intrazonal Fluvisol of Vietnam, as well as associated leaf litter and “suspended” soil from epiphytic ferns, has been given. The greatest number of bacteria, determined by the direct luminescence method, was associated with samples of Fluvisol, while the lengths of fungal and actinomycete mycelium were the largest in mountainous ferralitic soils. Bacteria of the genus Streptomyces, included in the saprotrophic bacterial complex of the studied substrates, make a significant contribution to the destruction of plant material. The bacteria of the phyla Firmicutes (80%) and Proteobacteria (15%) predominated in the prokaryotic community of the zonal red-yellow humus-ferrallitic soil, while the phyla Proteobacteria (51%) and Actinobacteria (38%) dominated in the sample of the “suspended” soil. The phyla Chloroflexi, Acidobacteria, Bacteroidetes, and Cyanobacteria were significantly less represented. With significant differences at the level of genera in the studied substrates, similar functional groups of microorganisms were identified: xenobiotic decomposers, nitrogen cycle bacteria, extremophiles, as well as bacteria that inhibit the growth of micromycetes. The metabolically active part of the prokaryotic community, represented by the phyla Proteobacteria, Actinobacteria, and Acidobacteria, was the highest in the “suspended” soil and the least active in the litter and horizon A of Ferralsol, which correlated with the high abundance of these phyla and the significant taxonomic diversity of bacteria in this locus. Functional genes (nifH and alkB) were detected in all studied substrates. The number of copies of functional genes was the highest in the “suspended” soil sample, which makes this locus promising for isolating strains with high biotechnological potential.
Respiratory Activity and Biodiversity of Microbiomes in Podzolic Soils of Post-Pyrogenic Spruce Forests in the Krasnoyarsk Territory and the Komi Republic
Authors: Grodnitskaya I. D. , Pashkeeva O. E. , Startsev V. V. , Dymov A. A.
Published: April 2024

Data on the microbiological properties of podzolic soils (Retisols) of old-growth spruce forests in the middle taiga of the Krasnoyarsk Krai and the Komi Republic are presented. It is shown that, despite the geographical distance, the soils of the regions are characterized by similar morphological and physicochemical properties. It was noted that in the soils of the spruce forests of the European North (R. Komi) and middle Siberia (Krasnoyarsk Krai), no significant difference in the accumulation of microbial biomass and the rate of microbial respiration was found. However, the content of carbon and nitrogen in soils, as well as microbial biomass, had significant differences in the qualitative composition of microbiomes in pyrogenic and non-pyrogenic soil horizons. A significant effect of the pyrogenic factor on the α-diversity of bacteria and fungi was noted. It was shown that representatives of the dominant phyla of bacteria (Proteobacteria, Actinobacteria and Planctomycetes) and fungi (Ascomycota, Basidiomycota and Mucoromycota) actively participate in the assimilation of organic matter with the presence of pyrogenic carbon. The microbiomes of the upper pyrogenic subhorizons include groups of carbotrophic bacteria (Thermomonosporaceae, Isosphaeraceae, Bacillaceae, Xanthobacteraceae) and fungi from the classes Dothideomycetes (Cenococcum), Eurotiomycetes (Penicillium), Sordariomycetes (Trichoderma), Leotiomycetes (Oidiodendron), Umbelopsidomycetes (Umbelopsis), which are capable of converting pyrolysis products into accessible and non-toxic substrates for other organisms.
Investigation of the Microbial Communities of Bentonites from Two Different Repositories under Different Temperature of Incubation
Authors: Kosheleva D. D. , Cheptsov V. S. , Stepanov A. L. , Tolpeshta I. I. , Krupskaya V. V.
Published: April 2024

Bentonite clays have a large specific surface area and a large Vume of pore space, which determines their high sorption capacity and allows them to be used as one of the barriers in the construction of deep geological repositories (DGR). It is expected that DGR will function for thousands of years, so the problem of forecasting changes that may occur during this time is relevant. During the functioning of DGR, bentonites can change their properties due to microbiological effects. In this work was analyzed the microbial community structure of two bentonites from 10th Khutor and Taganskoye disposal at different temperatures (25 and 60°C) of incubation. In bentonite from the 10th Khutor deposit, 10 phyla and 92 genera of bacteria were identified during incubation at 60°С, while 12 phyla and 94 genera were identified during incubation at 25°С. In bentonite from the Taganskoye deposit, 14 phyla and 87 genera were identified during incubation at 60°С, and 15 phyla and 123 genera were identified during incubation at 25°С. Samples were dominated with bacteria of Proteobacteria and Firmicutes phyla. It was concluded that is the main factor influencing the formation of the microbial in the studied bentonites community is temperature, and not the chemical and mineral composition of examined bentonites.
Chemical Structure of Organic Matter of Agrochernozems of Different Alocalization on the Slope
Authors: Artemyeva Z. S. , Danchenko N. N. , Kolyagin Yu. G. , Varlamov E. B. , Zasukhina E. S. , Tsomaeva E. V. , Kogut B. M.
Published: April 2024

The chemical structure of organic matter (OM) pools in agrochernozems confined to different zones of denudation-accumulation has been studied by solid-state 13C-NMR spectroscopy. It was revealed that in the erosion zone there are two competing processes occurring simultaneously: the decomposition of the “old” OM of the earlier underlying horizon and the stabilization of the fresh OM that has arrived with plant remains of cultivated plants (dynamic replacement of OM). Analytical data allow us to assert that the processes of dynamic replacement of eroded OM in the erosive zone quite effectively compensate for the processes of OM decomposition, as evidenced by the highest C/N ratio of all the studied OM pools in the eroding agrochernozem, along with the absence of significant differences in the integral indicators of their chemical structure. However, the constant removal of the upper soil layer from the eroding agrochernozem during each erosion event does not allow one to fully compensate for the OM quantitative losses in it. During the transportation of eroded material to the accumulative zone, the most labile part of OM can be mineralized. Accordingly, the OM again entering the accumulative zone is more transformed than that of the eroding agrochernozem. Nevertheless, the alluvial agrochernozem is characterized by an increased level of C accumulation in the soil as a whole and in all the studied OM pools. Accordingly, it can be stated that the constant OM inputs from the eroding position with its subsequent burial with each subsequent erosion event, as well as the repacking/aggregation of newly deposited OM, very effectively contribute to the deposition of C in the accumulative zone.
Comparison of Areal and Profile Distribution of Magnetic Susceptibility in Steppe Soils of the Russian Plain
Authors: Malyshev V. V. , Alekseev A. O.
Published: April 2024

A comparative analysis of areal and profile measurements of magnetic susceptibility was carried out in order to improve methods of surface sensing of the earth, as well as to take into account small-scale mapping of soils and the identification of anomalies associated with anthropogenic pollution or violation of the surface layer of soils. Two sites with Haplic Chernozems and one Haplic Kastanozems (Endosalic, Cambic) were studied. Additionally, a catena was studied on the territory of the Ergeninsky upland with the inclusion of sites in various positions of the landscape (eluvial, transeluvial, transeluvial-accumulative). The comparison of the areal and profile magnetic susceptibility measured to a depth of 30 cm showed a direct correlation (R2 = 0.7). It was found that the areal type of survey correctly captures the volumetric magnetic susceptibility (\({{\varkappa }_{{\text{s}}}}\)) to a depth of 30 cm. The variation of \({{\varkappa }_{{\text{s}}}}\) at sites with different types of soils reflects soil-climatic zonality and spatial lithological heterogeneity, expressed in different granulometric and mineralogical composition of the 0–30 cm layer on an area of 10 × 10 m. The areal magnetic susceptibility of soils can be an important additional indicator capable of reflecting the features of soil-forming, lithological and landscape geochemical processes occurring in the upper soil layer. Variation of \({{\varkappa }_{{\text{s}}}}\) at sites in different positions of the landscape occurs under the influence of planar flushing and a change in the direction of iron oxidogenesis processes depending on the position of the soil profile in the relief. The complex of measurements of areal and profile magnetic susceptibility can be used to study soil inhomogeneities caused by anthropogenic, paleocryogenic, geomorphological and lithogenic factors. Such an approach can be widely applied to the study of polluted soils and monitoring of agricultural land.
Genetic Features of Soils on Dense Parent Rocks of the Donetsk Ridge
Authors: Bezuglova O. S. , Boldyreva V. E. , Gorbov S. N. , Litvinov Yu. A.
Published: April 2024

The present study investigates morphological, physical and chemical properties of Chernozems at dense parent rocks. The research was carried out on the protected areas native soils of the north-west of the Rostov region. This territory is representing eastern slopes of the Donetsk Ridge, which predetermines the dense rocks release to the surface. It has been found that morphological, physical and chemical properties of Chernozems on dense rocks have emphasized their originality and uniqueness, and at the same time clearly have indicate their classification as Chernozem order. In comparison with the zonal soil – Calcic Chernozem – Chernozems on dense rocks are characterized by a reduced thickness of humus-accumulative layers, an increased of humus content, the presence of gravel in profile bottom half, a weak expression of calcareous accumulations, features of the particle-size distribution of soil components, even if it belongs to the same soil texture class. Chernozems on dense carbonate rocks either do not have accumulation or are characterized by a weak manifestation of secondary carbonates (pseudomycelia and nodules). This fact has differed such soil from the same order Chrernozems on fine-grained rocks (Calcic Chernozems) for which it is diagnostic criteria. Therefore, the mention of the suborder of these soils is incorrect in the designation. In the soil covering of the spurs of the Donetsk Ridge, dark humus soils are also occure, previously classified as incomplete developed chernozems, differing from chernozems by the absence of medium part of soil profiles.
Assessment of Soil Resistance to Contamination by Platinum Nanoparticles by Biodiagnostic Methods
Authors: Timoshenko A. N. , Kolesnikov S. I. , Kabakova V. S. , Evstegneeva N. A. , Minnikova T. V. , Kazeev K. Sh. , Minkina T. M.
Published: April 2024

Soil contamination with platinum nanoparticles is reproduced at a rapid rate, primarily because of the operation of vehicles with platinum exhaust gas converters. Already present on the territory with a concentration of platinum in the soil of more than 2 mg/kg, which is the maximum background content of 750 times. At the same time, the environmental risks of the adverse impact of platinum nanoparticles on the soil are practically not studied. The purpose of this work is to assess the consequences of different buffering capacities of soils to contamination with platinum nanoparticles in terms of biological parameters. Laboratory studies of soil resistance to pollution with platinum nanoparticles (PtNP) in the South of Russia were carried out, and their genetic properties were compared: Ordinary Chernozem (Haplic Chernozem (Loamic)), Brown Forest Soil (Eutric Cambisol), and Gray Sands (Eutric Arenosol). PtНЧ concentration studies 0.01, 0.1, 1, 10 and 100 mg/kg. Soil stability is assessed by the most sensitive and informative biological indicators of the state. It was found that the low content of PtNP (0.01, 0.1 and 1 mg/kg) in most cases does not lead to following the analysis of the biological state of the soil, and higher concentrations (10 and 100 mg/kg) lead to biological indicators. Soil enzymatic activity under PtНЧ contamination was inhibited to a lesser extent than phytotoxic and microbiological indicators. Common chernozem caused greater penetration to PtNP contamination than brown forest soil and gray sands. The results obtained were used to predict environmental risks in case of pollution of paid soils and to develop maximum allowable concentrations of platinum in soils of different buffering capacity.
Vertical Moisture Transfer Investigation on Lysimeters Taking into Account Substrates Granulometric Heterogeneity
Authors: Salugin A. N. , Balkushkin R. N.
Published: April 2024

The issues of soil-hydrophysical support of mathematical models of moisture movement, taking into account the heterogeneity of the soil, due to the spatial change in texture, are considered. The processes of vertical movement of moisture on large-sized lysimeters of the Federal Scientific Center of Agroecology of the Russian Academy of Sciences (Volgograd) were studied. The influence of statistical heterogeneity of hydrophysical parameters of lysimeter substrates was studied on models of moisture transfer dynamics and formation of gravity flow developed in the environment of the HYDRUS-1D software package. The change in texture along the vertical profile of the lysimeters and the related variability of the main hydrophysical characteristic (WRC) were taken into account. The granulometric heterogeneity of the substrates was estimated by the scaling method, according to the scale factors of the WRC parameters, assuming a normal probability distribution of the logarithms of the pore space capillary radii between soil particles. The effect of texture on water-holding capacity, boundary and initial conditions, intensity of gravity runoff and cumulative accumulation of moisture was studied.
Soil Formation on Sugar Industry Waste in the Central Chernozem Zone
Authors: Zamotaev I. V. , Gracheva R. G. , Konoplianikova Yu. V. , Dolgikh A. V. , Karelin D. V. , Belonovskaya E. A. , Dobryansky A. S. , Mikheev P. V.
Published: April 2024

Soils formed in treatment facilities of sugar beet factories in the forest-steppe zone of the Kursk region were studied. The technogenic factors of soil formation associated with the industrial sugar beet activity, and post-technogenic processes, acting during the abandonment of treatment facilities, are considered. The alternation of settling ponds and the earth walls separating them is the main factor determining the kind of “cellular” pattern of the soil cover. The mode of inflow and discharge of wastewaters, their composition, as well as the duration of the abandonment of settling ponds determine the specifics of the soils formed in the bottoms of the ponds. In operating settling ponds, under the periodic impact of sewage mixed with other wastes, dark-humus quasigleyic soils are developed (Calcaric Gleysol). When ponds are abandoned with previously removed calcareous sewage sludge (press mud), in the presence of perched water dark-humus quasigleyic soils (Gleyic Cambisol) are formed in 30 years; and in conditions of a variable-humid regime, quasigleyic zooturbated Chernozems are formed in 40 years. In settling ponds with preserved sewage sludge abandoned 20 years ago, soil formation has been noticeably active only in the upper 10–15 cm; below, the properties of the layered sediment are retained. Dark-humus technogenic arti-stratified soils are identified here (Spolic Technosols). On the earth walls, dark-humus typical soils (Eutric Cambisols (Organotransportic) are formed in 70 years; on the surfaces covered with calcareous sewage sludge, underdeveloped highly alkaline technogenic pelozems (Spolic Technosols (Transportic) are identified, in which the mixed material of technogenic sediments remains practically unchanged. All soils are alkaline and strongly alkaline, rich in organic matter, carbonates, phosphates, nutrients and some heavy metals from wastewater. According to the combination of properties and characteristics, the soils of the sugar industry treatment facilities have no direct natural analogues in the Central Chernozem region and are a vivid example of soils developing under ext-reme conditions of “resource excess”.
Content and Mobility Metals in Oligotrophic Peat Soils of the Cryolithozone of Western Siberia
Authors: Sokolov D. A. , Ivanova I. S. , Siromlya T. I.
Published: April 2024

The ongoing climatic changes have the greatest impact on natural ecosystems in high-latitude areas, as warming climate, as well as increasing anthropogenic load associated with the development of Arctic zone, contribute to the degradation of frozen peatlands and an increase in the thickness of seasonally thawed layer of soil. The relevance of studying peat oligotrophic soils (Cryic Histosols) of the northern territories of Western Siberia is associated with the fact that their degradation enriches natural waters by organomineral substances, which containing a large number of chemical elements, including heavy metals, contributing to changes in the hydrogeochemical properties of natural waters of the North. The article describes the main properties of peats sampled from different horizons of soil profiles laid down at key areas covering the territory of YNAO from north to south and from west to east. The chemical composition of soils was analyzed at the IPA SB RAS using standard methods. The concentrations of gross and mobile forms of metals (Fe, Ca, K, Na, Mg, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) were investigated by optical atomic emission spectrometry and flame atomic absorption spectrometry, respectively. It has been determined that a characteristic feature of the distribution of concentrations of chemical elements in peat oligotrophic soils of the northern part of Western Siberia is the presence of two maxima within the soil profile. The first is confined to the upper horizons showing signs of degradation, while the second is confined to the upper part of the permafrost. Statistical analysis using principal component method showed that low ash content, pH and C/N ratio are associated with high mobility of K, Cu, Zn and Mg. The mobility of Fe, Mn, Pb, Cd, and Cr is associated with an increase in ash content, pH, and Ntotal in the upper part of permafrost organogenic rocks.
Estimation of Carbon Stocks in Soils of Forest Ecosystems as a Basis for Monitoring Climatically Active Substances
Authors: Koptsik G. N. , Koptsik S. V. , Kupriianova I. V. , Kadulin M. S. , Smirnova I. E.
Published: April 2024

The eluvozems and soddy eluvozems on two-layer deposits dominating in the soil cover of the Zvenigorod biostation of Moscow State University contain, on average, 65–83 t/ha of organic carbon in the litter and a meter-deep layer of mineral strata. Carbon stocks are minimal in the soddy eluvozem of the complex spruce forest (59–68 t/ha), which is characterized by a lighter granulometric composition, and reach 76–92 t/ha in the soils of the birch–spruce and complex pine–spruce forests. At the same time, 3.3–5.8 t C/ha or 4–9% of the total organic carbon reserves are concentrated in the litter, and 64–69% in the upper mineral layer (0–20 cm). Different levels and profile distribution of organic carbon reserves in soils are determined by lithological and granulometric features and the nature of vegetation. The contribution of water-extractable organic carbon compounds to their total content in the upper mineral horizons of soils does not exceed 1.3–1.8%, microbial carbon, 1.7–2.4%. In acidic light loamy soils, the enrichment in calcium and potassium, the cation exchange capacity, the content of exchangeable bases, and the degree of saturation can serve as indicators of the content and reserves of organic carbon at the ecosystem level. The relationship with the content of finely dispersed fractions and oxalate-extractable Al and Fe is manifested to a lesser extent due to the similar origin and properties of soils. The variability of organic carbon stocks in soils is determined to the greatest extent by its content, the influence of which decreases with depth. Accounting for spatial heterogeneity, field measurements of the density and proportion of fine earth, and correct analytical determinations are essential components of the assessment of carbon stocks in soils of forest ecosystems as part of a national monitoring system for carbon pools and greenhouse gas fluxes under development.
One-Dimensional Spatial Boundary Value Problems of the Connected Thermoelasticity. Generalized Functions Method
Authors: Alexeyeva L. A. , Ahmetzhanova M. M.
Published: April 2024

Problems of definition of thermotension of a thermoelastic core with use of model of the connected thermoelasticity are considered. In this case in the equation of heat conductivity there is the divergence of speed of the movement of material points of the rod, and the elasticity equations contains the temperature gradient. On the basis of generalized functions method the generalized solutions of non-stationary and stationary boundary value problems have been solved at action of the power and thermal sources of various type including ones described singular generalized functions, under various boundary conditions on the ends of a core. Thermoshock waves which arise in such designs at action of impact loads and heat fluxes are considered, conditions on their fronts are received. The uniqueness of the set boundary tasks, including taking into account shock waves has been proved. Regular integral representation of the generalized solutions are given, which give the analytical solution of the tasks. Numerical implementation of solutions of a number of direct, return and semi-return boundary value problems of stationary fluctuations is carried out and results of computer experiments are presented
On the Problem of Determining the Position of the Source of Internal Waves
Authors: Baydulov V. G.
Published: April 2024

When bodies move in a continuously stratified fluid, the steady wave field moves along with the body and form a field of so-called associated internal waves. The flow incident on the body is usually assumed to be constant; non-stationary waves generated at the initial stage of motion are neglected. In this case, the body is modeled by point mass sources, and the wave field is found using the Green’s function method, followed by the use of asymptotic expansions based on the stationary phase method [1]. The inverse problem of determining the position of the source is solved from the wave field.
On the Contact Problem with Deformable Stamp in the Quarter Plain
Authors: Babeshko V. A. , Evdokimova O. V. , Babeshko O. M. , Zaretskaya M. V. , Evdokimov V. S.
Published: April 2024

In this paper, for the first time, a two-dimensional dynamic contact problem on the action of a deformable stamp on a quarter of the plane of a multilayer medium is strictly mathematically investigated. In contrast to the case of an absolutely solid stamp, a deformable stamp introduces additional features, consisting in the possibility of the occurrence of discrete resonances predicted by academician I.I. Vorovich. The paper shows that the use of a method based on the use of block elements makes it possible to obtain an equation describing resonant frequencies. To study contact problems with a deformable stamp made of materials of complex rheology, including smart materials, it is proposed in the paper to first conduct a study for the case of a deformable stamp made of a material of simple rheology described by Helmholtz equations. Solutions of boundary value problems for stamps of complex rheology, after that, are represented by a combination of solutions of boundary value problems for stamps of simple rheology.
Thermodynamically Compatible Hyperbolic Model for Two-Phase Compressible Fluid Flow with Surface Tension
Authors: Romenski E. , Peshkov I.
Published: April 2024

A two-phase flow model for compressible immiscible fluids is presented, the derivation of which is based on the use of the theory of symmetric hyperbolic thermodynamically compatible systems. The model is an extension of the previously proposed thermodynamically compatible model of compressible two-phase flows due to the inclusion of new state variables of the medium associated with surface tension forces. The governing equations of the model form a hyperbolic system of differential equations of the first order and satisfy the laws of thermodynamics (energy conservation and entropy increase). The properties of the model equations are studied and it is shown that the Young–Laplace law of capillary pressure is fulfilled in the asymptotic approximation at the continuum level.
Modeling of Dynamic Thermo-Elastic-Viscous-Plastic Deformation of Flexible Shallow Reinforced Shells
Authors: Yankovskii A. P.
Published: April 2024

A mathematical model of non-isothermal elastic-viscous-plastic deformation of flexible shallow shells with multidirectional reinforcement structures has been developed. Wave processes and weak resistance to transverse shear in curved panels are modeled in terms of Ambartsumian’s bending theory. The geometric nonlinearity of the problem is taken into account in the Karman approximation. The composition components are assumed to be isotropic materials, and their plasticity is described by the flow theory with a loading function depending on the strain rate and temperature. The connectedness of the thermomechanical problem under dynamic loading of composite shallow shells is taken into account. In the transverse direction of constructions, the temperature is approximated by a 7th order polynomial. The formulated two-dimensional nonlinear initial-boundary value problem is solved using an explicit numerical scheme of time steps. The thermo-elastic-visco-plastic and thermo-elastic-plastic behavior of fiberglass and metal-composite shallow shells orthogonally reinforced in two tangential directions, loaded in the transverse direction by an air blast wave, has been studied. It is shown that flexible curved fiberglass panels at certain points can additionally heat up by 14…27°C, and similar metal-composite conctructions – by 70°С or more. In this case, peak temperature values are kept at short-term intervals – on the order of fractions of 1 ms. It is shown that, unlike flexible plates, similar shallow shells (with the same reinforcement structure and the same characteristic dimensions) under dynamic loading in the transverse direction must be calculated not only taking into account the dependence of the plastic properties of the composition components on their strain rate, but also taking into account thermal response in such thin-walled constructions. A more intense inelastic deformation of curved composite panels is observed when they are loaded from the side of the convex front surface.
Towards Heat Transfer Critical Conditions for Flow of Fluids with a Nonmonotonic Dependence of Viscosity on the Temperature in Annular Channel
Authors: Kireev V. N. , Mukhutdinova A. A. , Urmancheev S. F.
Published: April 2024

The present work is devoted to mathematical modeling of the features of the flow of fluids with a nonmonotonic dependence of viscosity on temperature, which is inherent in some solutions and melts of polymers, as well as in a number of liquid metal alloys. For a given pressure drop, the critical conditions of heat transfer on the channel walls are found, which determine the fluid flow rate in the process of establishing a flow associated with the formation of a localized high-viscosity region.
Problem of Longitudinal Vibrations of a Viscoelastic Rod of Maxwell Type
Authors: Korzyuk V. I. , Rudzko J. V. , Kolyachko V. V.
Published: April 2024

In this paper, we study well-posedness in the sense of Hadamard of the Cauchy problem for a one-dimensional hyperbolic system of partial differential equations describing the longitudinal vibrations of a viscoelastic rod of Maxwell type with constant cross-section. We discuss some properties of the system and its solutions: the conservation of modified “energy”, the finite propagation speed, dispersion, and dissipation of solutions.
Quaternion and Biquaternion Methods and Regular Models of Analytical Mechanics (Review)
Authors: Chelnokov Yu.N.
Published: April 2024

The work is of a survey analytical nature. The first part of the work presents quaternion and biquaternion methods for describing motion, models of the theory of finite displacements and regular kinematics of a rigid body based on the use of four-dimensional real and dual Euler (Rodrigues–Hamilton) parameters. These models, in contrast to the classical models of kinematics in Euler–Krylov angles and their dual counterparts, do not have division-by-zero features and do not contain trigonometric functions, which increases the efficiency of analytical research and numerical solution of problems in mechanics, inertial navigation, and motion control.
The problem of regularization of differential equations of the perturbed spatial two-body problem, which underlies celestial mechanics and space flight mechanics (astrodynamics), is discussed using the Euler parameters, four-dimensional Kustaanheimo–Stiefel variables, and Hamilton quaternions: the problem of eliminating singularities (division by zero), which are generated by the Newtonian gravitational forces acting on a celestial or cosmic body and which complicate the analytical and numerical study of the motion of a body near gravitating bodies or its motion along highly elongated orbits. The history of the regularization problem and the regular Kustaanheim–Stiefel equations, which have found wide application in celestial mechanics and astrodynamics, are presented. We present the quaternion methods of regularization, which have a number of advantages over Kustaanheimo–Stiefel matrix regularization, and various regular quaternion equations of the perturbed spatial two-body problem (for both absolute and relative motion). The results of a comparative study of the accuracy of numerical integration of various forms of regularized equations of celestial mechanics and astrodynamics in Kustaanheimo–Stiefel variables and Newtonian equations in Cartesian coordinates are presented, showing that the accuracy of numerical integration of regularized equations in Kustaanheimo–Stiefel variables is much higher (by several orders of magnitude) than the accuracy of numerical integration Newtonian equations.
Analytical Method in the Linear Three-Dimensional Aerodynamics of a Thin Rectangular Wing
Authors: Sumbatyan M. A. , Samsonov I. K.
Published: April 2024

The paper develops an analytical method in the classical problem on a flow around a thin rectangular plate of large span. It is shown that with a specific expansion on an orthogonal system of functions with a weight defined by qualitative properties of the solution, the initial 2d integral equation is asymptotically equivalent to a set of independent 1d integral equations. For them, we construct an asymptotic method allied to a boundary layer method, which permits development of analytical representations for basic aerodynamic characteristics. Comparison with the numerical method of discrete vortices shows that precision of the obtained solution is good not only for large but also for medium span of the wing.
Dynamic Regimes of Biaxial Stretching of a Thin Ideally Rigid-Plastic Rectangular Plate
Authors: Tsvetkov I. M.
Published: April 2024

The stress-strain state arising during dynamic tension of a homogeneous rectangular plate of an incompressible ideally rigid-plastic material, which obeys the Mises–Hencky criterion, is considered. The upper and lower bases are stress-free, longitudinal velocities are set at the ends. The possibility of deformation of the upper and lower sides of the plate is taken into account, which simulates neck formation and further development of the neck. A small geometric parameter is introduced – the ratio of the average thickness of the plate to its length along one of the directions. At different time intervals, the order of smallness of the dimensionless functions characterizing the dynamic stretching mode may be different with respect to the geometric parameter, which determines one or another stretching mode. Two such characteristic modes have been identified, one is associated with a sufficiently high rate of removal of the ends of the plate from each other, the second with acceleration. In the second case, an analysis was carried out using the method of asymptotic integration, which allows us to approximately find the parameters of the stress-strain state.
Fastest Motion of a System of Interacting Mass Points along a Rough Horizontal Straight Line
Authors: Ananievski I. M.
Published: April 2024

An optimal control problem for a system of material points that move along a horizontal rough line is considered. The system moves due to forces of the interaction between the points and the forces of Coulomb’s dry friction acting between points and the underlying line. Only forward movement is allowed. A control algorithm is proposed which provides the fastest transition of the system from one state of rest to another.
The Dynamics of Small Satellites with the Three-Axial Gravitational Damper
Authors: Aslanov V. S. , Doroshin A. V.
Published: April 2024

The questions of the dynamics of the angular motion of nanosatellites with gravitational dampers are considered. The damper is a solid body rotating in a spherical cavity with a viscous liquid filling and creating internal friction with the dissipation of the kinetic energy of the angular motion. Unlike classical models of similar viscous dampers using the M.A. Lavrentiev with spherical dynamic symmetry of the body-damper, in this work the body-damper has a central triaxial ellipsoid of inertia, which increases the efficiency of interaction with an external gravitational field. This makes it possible to use almost any autonomous nanosatellite assembly as such an internal body-damper, placing it in a sealed spherical shell inside a spherical cavity with a viscous liquid in the center of mass of the main body-satellite body. The presence of a three-axis inertia tensor of the damper body changes and complicates the mathematical model of the angular motion in comparison with the classical one, which can be considered as a certain generalization and development of research in this direction.
On the Orbital Stability of Pendulum Periodic Motions of a Heavy Rigid Body with a Fixed Point, the Main Moments of Inertia of which are in the Ratio 1 : 4 : 1
Authors: Bardin B. S. , Maksimov B. A.
Published: April 2024

The motion of a heavy rigid body with a fixed point in a uniform gravitational field is considered. It is assumed that the main moments of inertia of the body for the fixed point satisfy the condition of D.N. Goryachev–S.A. Chaplygin, i.e., they are in the ratio 1 : 4 : 1. In contrast to the integrable case of D.N. Goryachev–S.A. Chaplygin, no additional restrictions are imposed on the position of the center of mass of the body.
The problem of orbital stability of pendulum periodic motions of the body is investigated. In the neighborhood of periodic motions, local variables are introduced and equations of perturbed motion are obtained. On the basis of a linear analysis of stability, the orbital instability of pendulum rotations for all values of the parameters has been concluded. It has been established that, depending on the values of the parameters, pendulum oscillations can be both orbitally unstable and orbitally stable in a linear approximation. For pendulum oscillations that are stable in the linear approximation, based on the methods of KAM theory, a nonlinear analysis is performed and rigorous conclusions about the orbital stability are obtained.
On Splitting of Separatrices Corresponding to the Working Mode of the Watt Regulator
Authors: Markeev A. P.
Published: April 2024

The nonlinear problem of the Watt regulator dynamics is investigated. It is assumed to be installed on a machine that performs the specific harmonic oscillations of small amplitude along the vertical. Viscous friction forces is believed to arise in the hinges of the regulator, and these forces are small. In the main operating mode of the regulator, its rods, carrying massive weights, are deflected from the downward vertical by a constant acute angle. If friction and vertical oscillations of the machine are neglected, then we obtain an approximate problem in which the dynamics of the regulator is described by an autonomous Hamiltonian system with one degree of freedom. On the phase portrait of the approximate problem, the operating mode corresponds to a singular point of the center type. The trajectories surrounding this point lie inside the separatrix, which is a homoclinic doubly asymptotic trajectory that passes through the equilibrium position corresponding to the vertical position of the rods with weights. In the phase portrait, this position corresponds to a saddle singular point. The Melnikov method is used to obtain the splitting condition for the unperturbed separatrix in the complete perturbed problem, taking into account dissipation in the hinges and vertical vibrations of the machine.
Stress Relaxation in Bended Viscoelastic Plate with Tension-Compression Asymmetry
Authors: Sevastyanov G. M.
Published: April 2024

The paper presents closed-form analytical solution to the plane-strain problem of stress relaxation in a bended plate with tension-compression asymmetry (TCA) in viscous properties. Reversible and irreversible strains are assumed to be finite. We utilize a linear viscous model with equivalent stress that is piecewise linear function of the principal stresses with TCA parameter. The specific features of the solution are discussed.
On the Contact Angles of a Small Sessile Drop and a Captive Bubble in View of the Size Dependence of Surface Tension
Authors: Sokurov A. A.
Published: April 2024

New mathematical models of a sessile drop and a captive bubble are constructed taking into account the size dependence of surface tension. If the Tolman length tends to zero the well-known Bashforth–Adams model can be considered as a special case of the constructed models. Numerical calculations of the contact angles are carried out for various numeric values of the equilibrium volume. The study shows that the size dependence of the surface tension leads to a violation of the consistency condition between the contact angles of a drop and a bubble in an external force field.
Cinematic Interpretation of Motion a Rigid Body in a new Solution of Grioli Equations
Authors: Gorr G. V.
Published: April 2024

In the article, a new solution is obtained for the problem on motion of a rigid body, having a fixed point, under the action of potential and gyroscopic forces. With use of the modified Poisson method, proposed by the author, it is shown that the motion of the body in this solution can be presented by rolling without sliding of the ellipsoid of inertia of the body along a plane fixed in the immovable space. This result may be considered as an analysis of Poisson result on interpretation of motion a rigid body in Euler solution.
One-Dimensional Spreading of Petroleum Products on the Surface of the Water
Authors: Kistovich A. V. , Chaplina T. O.
Published: April 2024

The process of quasi-one-dimensional spreading of oil product spots on the water surface has been experimentally and theoretically investigated. The theoretical model is based on an approximate equation obtained using the laws of conservation of the mass of the decomposed product and the total energy of the system. Approximate solutions of this equation and the results of experimental studies on the spreading of machine oil and crude oil in a narrow extended container are presented, and their good compliance with the theory is shown. A comparison is made with the process of two-dimensional axisymmetric spreading of a spot of the same petroleum products.
Amplitude-Frequency Characteristics and Stability Regions of a Two-Layer Liquid Under Angular Vibrations of a Solid Body
Authors: Ko Ko Win , Temnov A.N.
Published: April 2024

The article considers the problem of nonlinear oscillations of the motion of liquids completely filling an axisymmetric cylindrical vessel moving around a horizontal axis \(O{\kern 1pt} *{\kern 1pt} Y\). The motion of each fluid is assumed to be potential and formulated in a cylindrical coordinate system. The influence of nonlinear coefficients on the characteristics of dynamic processes during finite rotational movements of the vessel is estimated and the case of forced angular oscillations of a vessel with liquids relative to a fixed axis is considered. The main nonlinear effects associated with the rotation of the diameter of the interface of liquids are also revealed. An approximate solution of the obtained non-linear equations, found by the Bubnov-Galerkin method, was used in the article. As a result of the transformation, the amplitude-frequency characteristics and stability regions of a two-layer liquid are constructed under forced angular oscillations of a round cylindrical vessel.
Extraction of cesium and strontium from nitric acid hlw by a mixture of extractants of -18-crown-6 and -21-crown-7 derivatives in organic solvents
Authors: Koscheeva A. M. , Rodin A. V. , Ananiev A. V.
Published: April 2024

The processes of extraction of stable isotopes of cesium and strontium by solutions of macrocyclic polyesters in organic solvents from nitric acid mediums have been studied. The e ect of the crown ether structure and solvent type on the distribution coe cients of cesium ( D Cs) and strontium ( D Sr) has been studied. Extraction systems for the combined extraction of cesium and strontium were tested, in which 1,1,7-trihydrododeca uoroh eptanol and chlorohydrocarbons were used as solvents. It is shown that the highest D Cs and D Sr in the combined extraction of metals are observed when using a mixture of DTBDB18C6 and DCH18C6. Experimental data con rm the high e ciency of the use of crown ethers for the extraction of cesium and strontium into a separate fraction when handling radioactive waste.
Phosphorus concentration by sorbents based on polyacrylonitrile fiber modi ed with iron(III) hydroxide
Authors: Frolova M. A. , Bezhin N. A. , Kozlovskaia O. N. , Tananaev I. G.
Published: April 2024

The resu lts of phosphorus recovery by sorbents of our production on the base of polyacrylonitrile ber modi ed with iron(III) hydroxide from solutions with di erent pH were presented. The phos phorus degree of recovery, the dynamic exchange capacity, and the total dynamic exchange capacity of sorbents for phosphorus have been established. The output curves of phosphorus sorption were constructed, and the results of a study of the sorption physicochemical regularities (isotherm and kinetics) were presented. The sorption e ciency of 32P and 33P from rainfall samples using sorbents based on polyacrylonitrile ber modi ed with iron(III) hydroxide was evaluated. Monitoring of 32P, 33P in atmospheric fallout of the Sevastopol region was carried out.
Simulation of thermal decomposition of a nitric acid solution of acetohydroxamic acid during SNF reprocessing
Authors: Kalistratova V. V , Smirnov A. V , Belova E. V
Published: April 2024

A thermal analysis of a solution of acetohydroxamic acid in 12 mol/L HNO3 was carried out. The activation energy, the speci c thermal e ect, the duration and rate of the exothermic reaction, the pre-exponential factor, the onset temperature and self-heating value of the sample, and the change in pressure and the speci c volume of the evolved gases were determined. It was shown that under experimental conditions this reaction proceeds in the autocatalytic mode. On the basis of experimental data, a kinetic equation for the reaction was obtained, which was used to create a model of the reaction under various conditions. The reliability of the simulation results was veri ed by di erential scanning calorimetry.