Home – Home – Jornals – Thermophysics and Aeromechanics 2022 number 2

The annual cycles of the Northwestern Siberian warblers are analyzed in order to identify the features that determine the possibilities of further development of the Subarctic in the conditions of current climate change. The penetration of Philloscopus inornatus, Ph. trochiloides and Silvia curruca into the Subarctic is limited by woody vegetation, Ph. borealis - by high willows of the river valleys of the Middle Yamal. Ph. trochilus, Ph. collybita and Acrocephalus schoenobaenus inhabit the strip of subarctic tundra of Yamal. The last three species are moving in a northerly direction. The probable advance of forest-tundra-tundra landscapes to the north under conditions of further warming will entail the northward movement of forest and shrub birds, not only warblers, since there are no factors preventing this.

In this work reconstruction of past vegetation and fire dynamics in north Altai was performed by pollen and charcoal investigation of peat deposits of Maly Labysh Mire located in the upper reaches of the Kondoma River in Gornaya Shoriya National Park (52.6306° N, 88.0829°^{E, 490 м a. s. l.). Lithology and radiocarbon dating has shown that the swamp is of lacustrine origin. The lake originated about 3000 years ago, and about 2200 years ago it turned into a swamp. Spore-pollen analysis of lacustrine and peat deposits revealed repeated changes in the vegetation cover, probably caused by climate instability during the last 3000 years. In general, 2 humid millennial periods (3000-1800 cal. yr. BP and 550-200 cal. yr. BP) were identified when the role of fir ( Abies sibirica ) increased in the forests, alternating with 2 drier periods (1600-900 cal. yr. BP and 200 cal. yr. BP - contemporary) when the fir gave way to birch ( Betula pendula and Betula alba ) forests. The article represents also data on the dynamics of paleo fires in the area of the Maly Labysh Mire based on micro- and macrocharcoal analyzes. It was found, that in peat deposits of Maly Labysh Mire the maxima of micro-charcoals record wetter periods, but macro-charcoals - drier periods, while periodical flooding of the bog with river waters took place. With transition of mire from the flooding regime to unflooding regime, the microcoals and macrocoals began to synchronously reflect drier periods. The results of the study showed that the frequency and intensity of fires in Gornaya Shoriya in the last two thousand years correlate well with previously identified periods of lowering of the groundwater level in the mire [Kuryina, Blyakharchuk, 2020] and with a decrease in the amount of atmospheric precipitation in the Holocene [Arkhipov, Volkova, 1994]. A conclusion is drawn about connection of paleo fires with dynamics of humidity of climate, which in complex influenced on vegetation change in Gornaya Shoriya.}

In this work, a dendroecological study of the parameters of annual rings of Scots pine ( Pinus sylvestris L.) trees in the forest-steppe and steppe zones of Eastern Transbaikalia was carried out. For the first time, two new tree-ring chronologies (Nov and Tz) were built for the study area. They were constructed using digital growth ring anatomy methods and include four parameters: tree ring width, early wood width, late wood width, and late wood optical density. The analysis of the obtained chronologies made it possible to estimate the parameters of tree growth in the conditions of the forest-steppe (Nov) and steppe (Tz) zones and to reveal the presence of a reliable connection between them. Calculation of sliding correlation coefficients revealed periods of falling correlation coefficients below reliable values. This indicates the impossibility of constructing a generalized regional chronology for the forest-steppe and steppe zones of Eastern Transbaikalia. Comparison of the obtained chronologies with meteorological parameters (surface air temperature and atmospheric precipitation), with the calculated indices of aridity and moisture (Selyaninov’s hydrothermal coefficient, Pedya’s aridity index, Palmer drought severity index) showed the most sensitive characteristics of the annual ring in the study area. In the forest-steppe zone, the highest values of the correlation coefficients were obtained between the average annual precipitation and the annual ring width ( r = 0.59), early wood width ( r = 0.59), and also between the average air temperature for a hydrological year and the late wood width ( r = 0.51). For trees of the steppe zone, the largest significant correlation coefficients were obtained between water year precipitation and the annual ring width ( r = 0.43), early wood width ( r = 0.43), as well as between the Palmer drought severity index for June-September and the width of early wood ( r = 0.52).

The properties of a sandy Ferric Podzol over fluvioglacial deposits and the root mass of its 0-20 cm layer with Pinus sylvestris L. fine roots (≤ 3 mm in diameter) were studied in a mid-taiga cowberry-type pine stand. Keeping in mind the structure of the phytogenic field of a tree, the study was subdivided into the “trunk”, “crown”, and “gap” zones. The root mass of the forest floor and the mineral horizons was found to change in different directions in the said zones. In the forest floor, the “trunk” zone was more saturated with roots than the “gap” zone, while the trend in the soil mineral layer was the opposite. The highest root biomass was associated with sites that were the richest in soil nutrients and organic matter (NPKC). The cellulolytic activity and eco-physiological parameters of the microbiota varied in the studied horizons. Cellulolytic activity in the forest floor was the highest near tree trunks, while the spatial variation of this parameter in the mineral body of the soil was less pronounced. A correlation was detected between the contribution of root respiration to total СО₂ emissions from the soil surface and the biomass of fine roots (≤3 mm) in the 0-20-cm soil layer. The effect of the soil thermal regime on root mass in different zones of the phytogenic field was studied. Soil temperature variation due to the redistribution of solar energy by the canopy results in a higher root mass in areas receiving more heat. The zone with better heated soils is the canopy gaps. The effect of the temperature of the soil’s root mass is more explicit in the mineral layer. The results of this study can be used in environmental monitoring and in predictive assessments of the effects of climate change on boreal forest ecosystems.

The abundance, biomass, and size-morphological structure of heterotrophic bacterioplankton were determined in freshwater environments of the Svalbard archipelago (Norway), differing in morphometry and trophic level. The quantitative parameters of bacterioplankton varied within wide limits and increased along the trophic gradient of the waters. Medium-sized cocci and coccobacilli reached up to one third of the total abundance and a half of the total biomass of bacterioplankton. The abundance and biomass of small cocci varied over a wide range, while small rods were, on the contrary, relatively stable in these parameters. With an increase in trophic status, the proportion of small cocci in the community increased, while the proportion of rods and vibrios decreased. The proportion of medium-sized cocci and coccobacilli changed less, although there was a tendency for its increase in the trophic gradient.

Aquatic vascular plants at different stages of their life cycle exhibit different physiological and metabolic activity, resulting in changing habitat conditions for hydrobionts. The hydrochemical parameters of the environment, the concentrations of phytoplankton pigments, the abundance of bacteria and zooplankton were studied in experimental ecosystems (microcosms), including actively vegetating and completing the vegetation of aquatic plants. In microcosms with actively vegetating hornwort Ceratophyllum demersum L. the concentration of P_tot, Mg²⁺ and BOD ₅ increased, and Na⁺ and Ca²⁺ decreased. In systems with a dying arrowhead Sagittaria sagittifolia L. the concentration of K⁺ increased to the greatest extent, P_tot, Cl^-, and BOD₅ to a lesser extent, and the concentrations of SO₄^2- and O₂ dissolved in water decreased. In the presence of plants, higher concentrations of phytoplankton pigments were observed in comparison with the control. The quantitative indicators of bacterioplankton did not differ. The number and biomass of zooplankton in general and the dominant species Daphnia longispina in microcosms with plants exceeded these indicators in the control. The hornwort, which lost half of the biomass, but continued vegetation, had a stronger stimulating effect on the abundance of zooplankton than the arrowhead, which finished vegetation.

This article presents the results of the transformation of natural ecosystems due to an emergency diesel fuel spill at CHPP-3 in the Norilsk Industrial District. Oil products have negatively affected the vegetation of the floodplains of the Bezymyanny and Daldykan creeks and Ambarnaya River. Some of the plant communities have been significantly transformed due to direct contact with diesel fuel, which is expressed in a noticeable decrease in the indices of alpha, beta, and gamma diversity. The vegetation of the lower reaches of the Ambarnaya River is the most polluted. No effect of oil products has been recorded in the floodplain of the Pyasina River. Here, the indices of phytodiversity of conditionally disturbed communities are comparable to those of background vegetation. All bryophytes and some species of vascular plants of dry and drained habitats are extremely nonresistant to oil pollution. Conversely, aquatic and streamside-aquatic species of perennial long- and short-rhizome grasses are resistant to pollution. The diversity of vegetation affected by oil products is represented by five associations and three subassociations of three classes of floristic-sociological classification. We describe three associations ( Chamaenerio latifolii - Sanguisorbetum officinalis ass. nova, Eleocharo acicularis - Arctophiletum fulvae ass. nova, and Equiseto arvensis - Salicetum dasycladi ass. nova) and three subassociations ( Chamaenerio latifolii - Sanguisorbetum officinalis typicum subass. nova, Chamaenerio latifolii - Sanguisorbetum officinalis angelicetosum decurrentis subass. nova, and Caricetum aquatilis cerastietosum jenisejensis subass. nova) for the first time.

On the territory of South Kazakhstan (Almaty region) there are old abandoned warehouses with prohibited and unused pesticides, the active substances and metabolites of which pollute natural water sources and pastures of farm animals located nearby. The analysis of blood samples of 50 heads of cattle from five monitoring points of the Almaty region was carried out for the presence of micronucleus in erythrocytes, genomic mutations and chromosomal aberrations in lymphocytes. Cell cultivation and preparation of preparations were carried out by standard cytogenetic methods. The frequency of erythrocytes with micronucleus in cattle kept in experimental plots was 3.3 %, which is 4.7 times higher than in the control group. The incidence of genomic mutations in the blood system of experimental groups of animals exceeded the same indicator in the control group by an average of 1.6 times, and chromosomal aberrations - by 9.1 times. The proportion of hypodiploid cells was 46 % of the total number of genomic mutations. Polyploidy accounted for up to 17 %, and hyperdiploidy was found in 5 % of cells. Analysis of individual indicators of general cytogenetic instability in the blood system of animals showed that hyperdiploidy and chromosomal aberrations are the main components of this indicator, which, on average for five monitoring sites, exceeded the control data by 7.9 times. Statistical data processing allows us to make a conclusion about the genotoxic effect of prohibited and unused pesticides on the body of cattle, which have clastogenic, aneugene and mutagenic effects even after 30 years.

Introduced woody plants are widespread in the green spaces of Siberia, the mycobiota of which is formed on the basis of widespread local species. As a result of studying the biota of fungi associated with Populus balsamifera L., Acer negundo L., Ulmus pumila L., Prunus maackii Rupr. and Tilia cordata Mill. 105 species of mainly agaricoid macromycetes, common for Siberia, were identified and characterized mainly by a wide trophic and topical specialization. Many of them are characterized as synanthropic organisms. The largest number of macromycete species is generally associated with A. negundo (61), the smallest with U. pumila (16 species). The mycobiota of all tree species, except for T. cordata , is dominated by wood-destroying species. More than half of the identified wood-destroying fungi are capable of parasitism, and in the green plantations of Krasnoyarsk they form fruit bodies more often on living tree introduced species, while outside the city on aboriginal tree species, fruiting of these mushrooms begins only after the tree dies. The largest number of wood destroyers was found on A. negundo (39), among which Flammulina velutipes (Curtis) Singer dominate. and Bjerkandera adusta (Willd.) P. Karst. With a relatively rich biota of ground macromycetes associated with A. negundo (22 species) and T. cordata (17 species), there is a significant difference in the ratio of its constituent ecological-trophic groups: soil and litter saprotrophs are mainly associated with the first tree species (dominated by representatives of families Agaricaceae , Marasmiaceae and Psathyrellaceae ), with the second - mycorrhiza formers (dominated by Inocybe spp ., Inocybaceae ). In general, among the macromycetes of green spaces formed by introduced tree species, the mycobiota of U. pumila and P. maackii is distinguished by the least taxonomic and ecological-trophic diversity.

The pulp and paper industry is developed in the northern regions. Ecosystems of northern rivers are less capable of biological self-rinsing and more sensitive to anthropogenic pollution. Assessing the pollution of water bodies is important for controlling the conservation of their bioresources. This article provides a literature review which illustrates the main impacts of wastewater of the pulp and paper industry on aquatic ecosystems. It will be useful for monitoring practitioners. This paper discusses examples of the impact of wastewater of the pulp and paper industry on aquatic organisms at different levels of organization - from the molecular to the ecosystem. The review describes the responses of aquatic zoocenoses (zooplankton and zoobenthos) to pollution and the effects of specific substances that enter water bodies from the effluents of the pulp and paper industry. The paper analyses information about transformation of bottom sediments of rivers and lakes in the wastewater zone. An overview of data is given, which evaluates the impact of thermal pollution. This type of pollution often characterizes industrial wastewater. One of the large rivers in the European part of Russia is the Vychegda River. The rivers in its basin are important in the Komi Republic. Therefore, monitoring the condition of communities of aquatic organisms that inhabit it is an urgent task. This paper presents the results of hydrobiological observations carried out in the Vychegda in the 1980s. At that time, changes in communities of aquatic organisms in the area of pulp and paper industry were shown.

The results of three-year measurements (2018-2020) of hydrophysical and hydrochemical indicators of the Vychegda River in places where treated wastewater is discharged from the Mondi Syktyvkar JSC pulp and paper mill are presented. At conventionally background stations and exposed to wastewater in concentrations significantly lower than the MPC: mineralization, the content of ions of Ca²⁺, Mg²⁺, Cl^-, SO4^2-, NO3^-, heavy metals, oil products, anionic surfactants, benz[a]pyrene were noted, an excess of MPC was noted for Suspended substances, COD, РО4^3-, Fe, Mn. Studies have shown that in connection with the modernization of the treatment facilities of Mondi Syktyvkar JSC, there is a noticeable improvement in the quality of wastewater and a decrease in the environmental load on the ecosystem of the Vychegda River in places of their discharge. With a high water level in the Vychegda River (2018-2019) for all investigated hydrochemical indicators in the places of wastewater discharge, no significant excess over conditionally background values - was revealed. It was possible to register the impact of pollutants only in the low-water period (2020), with a decrease in the degree of dilution by river waters of effluent from treatment facilities. During this period, at the observation points in the places of wastewater discharge, a significant increase was noted relative to the conditionally background indicators of the concentration of ions Cl^-, SO4^2-, РО4^3-, NH₄⁺, S_tot, K, Na, Fhenol, as well as COD, Permanganate Value, turbidity, electrical conductivity. In terms of environmental, sanitary and toxicological indicators, the waters of all surveyed observation points were assigned to the 3rd class of water quality (satisfactory purity).

Like most of the northern rivers, the Vychegda river, the second largest water system of the Komi Republic and the main tributary of the Northern Dvina river, is experienced intense anthropogenic load. Agricultural, domestic and industrial, at a greater extent, waste waters are currently the main polluting sources of river waters. The largest pulp and paper enterprise in Russia, Mondi Syktyvkar JSC, is located on the Vychegda riverbanks among the numerous enterprises operating here. The composition and structure of the zooplankton communities were investigated in the Vychegda river area, where effect of waste waters from the pulp and paper enterprise is observed. The research aim is to find out there is a negative impact of the conditionally treated waste waters on the aquatic biota. As a result, a rich species composition and quantitative development of zooplankton communities were established for the investigated river area. Rotifera was the dominant group on species abundance, number and biomass. This is characteristic feature of zooplankton communities in the watercourse as a whole. The indicator species of waters with a high level of pollution were registered both at points located in the area of waste waters influence and at the background plots of the river. The species which are not peculiar to the natural waters of the river were found in points of waste water discharge. The dominant complexes are represented by 9-15 species лучше. Their composition differs at background, waste waters and downstream points. According to the state of zooplankton communities, the river waters in the studied area are conditionally clean, except the points located downstream of waste waters discharge, where they are qualified as eutrophic.

We characterized the composition and diversity of benthic communities, as well as the current ecological state of Vychegda River in the zone of influence of wastewater from a pulp and paper production. A high diversity of benthic fauna and quantitative indicators of its development which are not typical for benthic biocenoses in the middle reaches of Vychegda River were registered. In the composition of the zoobenthos, 23 taxonomic groups of benthic invertebrates were identified. For 7 model groups, we identified 125 species and forms, as well as a persistent complex of species dominating in the studied section of the river. The model groups were dominated by indicator species of о-β- and β-saprobic conditions. In general, the water quality assessment indices based on the composition and structure of benthic invertebrate communities characterize the state of the river at the monitoring site as “satisfactory”. An exception was the wastewater discharge points, where the role of indicator species of α- and polysaprobic conditions was higher and the values of most of the indices were significantly lower.

In 2018-2020. we identified in Vychegda and Sysola Rivers new for the Komi Republic and the entire Northern Europe species of copepods: Elaphoidella bidens, Phyllognatopus viguieri, Paracyclops imminutus. All of these species were found exclusively in the areas of wastewater discharge of a timber processing company or urban wastewater of the city of Syktyvkar. The analysis of the identified specimens showed their morphological similarity with the type descriptions, only in P. viguieri from Sysola River we found certain features in the structure of the furca which distinguished it from the type form. As a result of molecular genetic studies, we determined that the crustacean Attheyella crassa native to the Vychegda basin is identical in the structure of mtDNA-COI to specimens of this species from the Moscow Oblast, while E. bidens from the zone of influence of wastewaters of a pulp and paper production company in the Vychegda basin differed from representatives of the species from the Moscow Oblast by 14 % and was similar to E. bidens from New Zealand. This characteristic feature of the Vychegda population of E. bidens indirectly confirms that the mechanism of invasion of the species into a new habitat is associated with wastewater. The identified species of copepod crayfish which are new for the Komi Republic represent a facultative synanthropic fauna in the study region that is capable of development only in urbanized areas.

The results of a study of summer phytoplankton (July 2018-2020) in the middle reaches of the Vychegda River in the places where treated wastewater is discharged from the Mondi Syktyvkar JSC pulp and paper mill are presented. In the phytoplankton of the investigated section of the River, 263 species with varieties of algae of seven divisions were identified: Cyanoptokaryota - 8, Ochrophyta - 4, Rhodophyta - 1, Euglenophyta - 1, Bacillariophyta - 232, Chlorophyta- 15, Charophyta - 2. Mostly widespread in terms of diversity, eurytopic species. For three years of research, the stability of the complex of dominant species and structural diversity has been noted for phytoplankton communities. The basis of the dominant complexes is formed by species from the genera Aulacoseira , Dolichospermum , Pandorina , Eudorina , Closterium , etc. The composition of dominants is similar for conditionally background points and the zone of discharge of fine waters. Below the wastewater discharge site, a massive development of the thermophilic species of diatom Diadesmis confervacea , an indicator of thermal pollution, was noted. The total number of phytoplankton in the Vychegda River at the studied stations was recorded in the range from 1150 to 18000 thousand cells / dm³, biomass - from 0.01 to 0.29 mg / dm³. The ratio of the total abundance and biomass of phytoplankton algae and indicator species forming a complex of dominants reflect an increase in the trophic status of the waters of the surveyed areas and a high degree of anthropogenic load on the ecosystem of the Vychegda River. On the basis of algoindication, the waters of the conditionally background and receiving wastewaters of observation points were assigned to the III quality class (with the quality category 3b - slightly polluted).

The paper is presented the results of a study of the species diversity and developmental stability of individuals of common fish species from the Vychegda River in the area of treated wastewater discharge of one of the largest pulp and paper mill in the European northeast of Russia. It was shown that for the period from 2018 to 2020, perch, roach, and bleak predominate in the catches of a set of nets with a mesh size of 10 to 60 mm in the littoral zone of the monitoring sites. These species are widespread representatives of the ichthyofauna in the basin of the studied river. The catches included non-native species such as white-eye bream, asp and pike-perch. They recent appearance of which became possible due to the construction of canals connecting the Northern Dvina River basin with other river systems. Indices of species diversity (the number of species, their relative abundance and the Shannon index) in monitoring sites from the region of the studed of pulp and paper production is similar. The integral index of individual development assessing, based on the fluctuating asymmetry indicator, indicates the absence of a negative effect on the formation of bilateral morphological structures in early ontogenesis in fish that lived as in the impact as in the conditionally background sits. It was recommended to conduct an additional study to identify physiological disorders in the body of fish or the accumulation of heavy metals or other pollutants in their tissues and organs to clarify the obtained results.

The results of long-term studies of the collembolan population in the gradient of pollution of pine and spruce forests (middle taiga) in the zone of influence of pulp and paper industry (JSC Mondi SLPK, Komi Republic), the main pollutants of which are oxides of carbon, nitrogen, sulfur, hydrogen sulfide, mineral dust are given. The study was carried out in the period when the total amount of emissions was 20-30 thousand tons (2003, 2007-2009 years) and 10-15 years after their reduction by 2-3 times to 10 thousand tons (2018-2019 years). It was shown that after a decrease of emissions, the species richness of springtails significantly increases in the zones of strong and medium coniferous forests, but their number decreases in all zones, which may be associated with weather conditions. It was found that in pine forests, especially in the background plots, euedaphic species predominate, and the proportion of hemiedaphic and epiedaphic species increases in the zone of sting impact. At the same time, the spectrum of life forms, biotopic groups, the structure of the springtail population does not undergo significant changes over the course of 10 years. In spruce forests, on the contrary, differences were revealed in these parameters between years of research, which are expressed in a change in the dominance of species, their relative life forms and biotopic groups. The observed changes in the communities of springtails in spruce forests are apparently determined by changes in the ground cover. In general, there has been a significant improvement in the state of the collembola community of spruce forests in the zones of strong and medium imact from 2003 to 2019.

The analysis of the state of soil macrofauna during the period of reduction of emissions of pulp and paper production revealed changes in the structural parameters of invertebrate communities in the pine and spruce forests of the impact, buffer and background areas. The macrofauna of pine and spruce forests is characterized by a high degree of similarity and low diversity at the level of large taxa. It is a typical feature of coniferous forests in the middle taiga subzone. The species richness of invertebrate communities is estimated for the period from 2003 to 2019 years. It is comparable for the impact and buffer areas, and it is almost twice lower than for the background area. The total number of macrofauna, as well as taxonomic groups, varies by periods and areas of load. In 2007 and 2010, a change of dominant species was observed in the pine forests of the impact area. Lithobius curtipes C. L. Koch, 1847, Pella humeralis (Gravenhorst, 1802) predominated in the buffer and background area, and Philonthus rotundicollis (Menetries, 1832), Philonthus politus (Linnaeus, 1758) predominated in the impact area. In 2018, no changes of dominants were detected in pine forests, as in spruce forests (in 2006, 2010, 2019). Dendrobaena octaedra (Savigny, 1826) and L. curtipes were dominants in the impact, buffer and background area. The predominance of zoophages is typical for all the studied plots. The number of some taxa (Lumbricidae, Diplopoda, Elateridae) indicated an increase in the relative abundance of saprophages in the soils of coniferous forests at the impact area. The soils of background area, with high natural acidity, are unsuitable for activity of invertebrates. Due to the effect of neutralizing the acidity of the soil near the pulp and paper enterprise favorable conditions are created for them.

The paper presents a review of the methods of experimental investigations of the Görtler vortices in boundary layers. The proposed models are used in experiments for the analysis of the Görtler instability; the major methods of Görtler vortex generation are described. It has been revealed that spontaneous uncontrolled emergence of the Görtler vortices is caused by the roughness of model surfaces (especially in the area of the leading edge of a plane model) and free-stream disturbances. Effective methods of introduction of controlled stationary and nonstationary disturbances generating the Görtler vortices in the boundary layer are described. The methods of experimental measurements of boundary layer parameters in the presence of the Görtler vortices are presented; the diagnostic capabilities of these methods are demonstrated, and the major scientific results obtained by these methods are reported.

A numerical model of the dynamics of a flat localized region of turbulent perturbations of non-zero buoyancy in a linearly stratified medium has been developed on the basis of the mathematical model, including differential equations for Reynolds stresses transfer and algebraic model of a vector of turbulent scalar flux. The evolution of a heated turbulent spot has been considered. The non-zero buoyancy is the reason of an increase in the geometrical size of the turbulent spot and generation of internal waves of greater amplitude. The generation of the total energy of turbulence is insignificant even in the case when the initial potential energy of a turbulent spot of non-zero buoyancy is comparable to the initial total energy of turbulence in it.

The present study shows that enhancement of mixing efficiency (increasing the total pressure of the mixture) requires expansion of the cross section of the high-pressure gas flow. It is found that the parameters of the mixtures are identical in the cases of distributed and one-step mixing of the perfect gas flows. However, distributed mixing (multistep mixing as a finite-dimensional analog) is more reasonable because it ensures flow control to provide conditions to satisfy the existence of a steady flow in the channel.

The present study shows that enhancement of mixing efficiency (increasing the total pressure of the mixture) requires expansion of the cross section of the high-pressure gas flow. It is found that the parameters of the mixtures are identical in the cases of distributed and one-step mixing of the perfect gas flows. However, distributed mixing (multistep mixing as a finite-dimensional analog) is more reasonable because it ensures flow control to provide conditions to satisfy the existence of a steady flow in the channel.

The paper presents the results of computational and experimental study for parameters of the innovative pulse-mode ejector used as a flow control device for flight vehicles. The ejector comprises a Helmholtz resonator adjusted to a certain resonant frequency. The computational and experimental results revealed the existence of resonant modes in ejector operation providing a higher efficiency. Simulation for internal aerodynamics for the pulse-mode ejector can explain a high efficiency calculated by the high-pressure gas flow rate, as well as advantages/shortcomings in other metrics (compared to the steady operation mode). The margins of efficient operation of this resonance-operating ejector in the metrics of gas flow rate are calculated. The perspectives for using the ejector as a flow control devices are discussed.

In this paper, analytical analysis on g-Jitter induced natural convection flow in microgravity behaviour is theoretically examined in the existence of Lorentz forces in a vertical micro-channel. Effects of velocity slip and temperature jump are also taken into account. A single component of time harmonic g-Jitter is considered. Solutions are obtained for the velocity and temperature profile with a combined effect of oscillating g-Jitter driving force and induced Lorentz force, the latter resulting from an application of a transverse magnetic field. Four limiting cases are carried out based on the solutions. Numerical procedures are under see for various active parameters namely: g-Jitter induced frequency, fluid-wall interaction, rarefaction, and Hartmann number. The results of the research unveiled that, the amplitude of the velocity decreases at a rate inversely proportional to the g-Jitter induced frequency and with increase in the Hartmann number. The induced flow oscillates at the same frequency as the affecting g-Jitter. Furthermore, a magnetic field can be applied to suppress oscillating flows joined with g-Jitter, it is more effective in damping low frequency flows but only has a moderate damping effect on the flow induced by high frequency g-Jitter. Also, the temperature jump condition induced by the effects of rarefaction and fluid-wall interaction parameter plays relevant impact in slip-flow natural convection.

A physical-mathematical model of a laminar axisymmetric flow of a power-law fluid through a sudden pipe contraction under non-isothermal conditions is presented with allowance for dissipative effects. The rheology of the liquid medium is determined by the Ostwald-de Waale law. The effective viscosity is specified as a temperature function. Two options for setting the temperature boundary conditions on a solid wall are considered: the first implies invariable temperature along the pipe wall; and the second assumes a constant temperature value on the wall except for the area in the contraction plane vicinity, where the boundary is exposed to a zero-heat flux. The process is studied numerically using the finite-difference method. The main characteristics of the flow are calculated and visualized. The effect of thermal boundary conditions on the fluid flow structure and local pressure losses is analyzed.

In this paper, multi-objective optimization of geometric parameters of spirally-cross-corrugated (SCC) tubes is carried out using numerical methods, genetic algorithms (GAs), and artificial neural networks (ANNs). First, the turbulent flow is numerically characterized in various SCC tube geometries using a finite volume method with the realizable k-ε turbulence model. In this approach, the heat transfer coefficient and friction factor f in tubes are calculated. First, two parameters (corrugation pitch-to-diameter ratio ( PR = p / D ) and corrugation depth-to-diameter ratio ( DR = e / D )) are examined in a turbulent flow regime that affects the strength of quadruple longitudinal vortex flows and thermal characteristics. At the final step, using the obtained polynomials for neural networks, multi-objective genetic algorithms (NSGA II) are employed for Pareto based multi-objective optimization of flow parameters in such tubes. This analysis considers two conflicting parameters, f Re and Nusselt number Nu with respect to three design variables, Reynolds number (Re), values of PR and DR . Some interesting and important relationships between the parameters and variables mentioned above emerge as useful optimal design principles involved in the heat transfer of such tubes through Pareto based multi-objective optimization. Such important optimal principles would not have been obtained without the use of a combination of numerical techniques, ANN modeling, and the Pareto optimization.

The oscillating flow of a viscous incompressible fluid in a rigid circular pipe with local constriction has been studied numerically. Fluid viscosity and density of liquid, channel diameter and constriction, as well as amplitude-frequency characteristics of the flow rate are identical to those of the blood flow in the human popliteal artery with stenosis. Reynolds number in the area of stenosis is Re » 5×10³, dimensionless pulsation frequency is Sh = 0.43×10^-3, and normalized constriction of the channel is d = d / D = 0.4. The flow under consideration is characterized by the fact that during one oscillation period the fluid flow rate changes direction four times. This contributes to laminar-turbulent transition when the jet discharges from a contraction throat into the main flow. Qualitative features and quantitative parameters of pulsating flow have been determined including distribution of friction stresses along the channel wall.

A semi-analytical study is performed to examine transient Taylor-Dean flow in a composite annulus within two concentric cylinders partially filled with porous material. In the present model, the circumferential flow is set up as a result of azimuthal pressure gradient as well as the rotation of the two concentric cylinders. The equation governing the flow is rendered non-dimensional and transformed into ordinary differential equation using the well-known Laplace transform technique. The solution is then transformed back to the time domain using the Riemann-sum approximation (RSA) approach. The solution of the steady-state of the present model including the implicit finite difference (IFD) is also computed to validate the result obtained from the RSA approach. It is important to note that the surface resistant force can be controlled by choosing suitable values of β .

The division of diseases into organic and functional has its own long history and, despite the significantly increased technical capabilities of studying the structural and functional features of vital activity both in normal and in various pathological processes, still continues to divide scientists into two opposite camps. The article provides a brief historical and philosophical analysis of the problem under study in an attempt to prove the inconsistency of the functional concept of general human pathology. As an example, the most common functional diseases of the gastrointestinal tract are given, in which structural disorders are localized in the central nervous system.

Comparison of descriptions of historical observations of passage of Venus on a disk of the Sun on May, 26th, 1761, on May, 23-24rd, 1769 is spent and on December, 8-9th, 1874 with my personal observations on June, 8th, 2004 and on June, 6th, 2012 the opportunity of detection atmosphere of Venus Is studied at pass off the planet from the solar disk. From the point of view of comparison with my observations of transites 2004 and 2012, are especially interesting descriptions of observations 1874 executed in Odessa, Teheran and Luxor. Is considered extreme states of consciousness during transient astronomical observations and an opportunity of their reflection. Carefulness and attentiveness are connected with short duration and a rarity of the phenomenon. Observation of transites of Venus on a disk of the Sun are interesting to verification of historical and own observant experience.

This paper presents conventional and innovative technologies for wastewater and industrial solution purification from Ni²⁺ ions and accompanying non-ferrous metals. Several methods including sorption, extraction, flotation, chemical, electrochemical, membrane and microbiological separation of impurities from the liquid phase are introduced. Chemical methods involve nickel deposition in the form of insoluble compounds (hydroxide, carbonate, bicarbonate, sulphide, dimethylglyoximate), or metal powder by adding certain reagents. Carbon, aluminosilicate and some other inorganic materials in initial and pre-modified forms, as well as weakly acidic, strongly acidic, weakly basic, including chelate ion-exchange resins and fibres are used for sorption. The extraction of nickel ions from the liquid phase is carried out with the derivatives of organophosphorous, carboxylic acids, as well as with materials that combine the properties of solid sorbents and liquid extractants. Nanofiltration and reverse osmosis are the most relevant methods among the membrane purification methods. Foam separation of nickel ions during flotation is carried out using anionic and nonionic surfactants. Electrochemical methods include electrocoagulation, electroextraction, electroflotation, and electrodialysis using soluble and insoluble electrodes, as well as galvanic coagulation without connection to external power. Living and non-living biomass of some species of bacteria, fungi, algae, as well as their complex mixture in the form of activated sludge can be deployed for microbial extraction of nickel from aqueous media. The above purification methods are considered on the basis of case studies, both generally applicable and specific ones. Their advantages and disadvantages are briefly described.

The currently widespread methods of processing fuel oils obtained during the primary separation of oil are complex multistage processes, including preliminary vacuum distillation and subsequent cracking of the resulting vacuum gas oils, as well as the oxidation of residual tar into bitumens. For small-scale industries, such processes are costly and, in some cases, unprofitable. The article proposes a technology for thermolytic processing of fuel oil over a tin-lead melt in a semi-continuous reactor. The main advantages of the proposed technology are low process temperature and pressure close to atmospheric, as well as almost complete elimination of the formation of carbon deposits on reactor walls. The reported results describe experiments on thermal cracking of fuel oil carried out according to two kinds of destructive distillation: the classical version, and the version involving a tin-lead melt. It is shown that during destructive distillation on a tin-lead melt, deeper cracking occurs in comparison with classical destructive distillation. The content of gasoline fraction (IPB-180 °С) and diesel fraction (180-360 °С) in thermal gas oil obtained by means of classical destructive distillation is higher than in thermal gas oil obtained by destructive distillation on tin-lead melt, while the content of fractions boiling above 360 °C is lower. The group composition, density and dynamic viscosity of thermal gas oils differ insignificantly. For thermal gas oil obtained over a tin-lead melt, a slight decrease in sulphur content is observed. Analysis of thermal gas oils for tin and lead showed their absence. Thermal gas oils have a high content of aromatic compounds, which makes them a promising raw material for needle coke production. Multiple analysis of the tin-lead alloy after the completion of the process showed that the alloy was free from mechanical impurities present in the fuel oil, it also did not contain coke released during thermolysis, and the mass of the alloy remained constant, which means that in this case the alloy plays the role of an effective heat carrier, which makes it possible to deepen fuel oil thermolysis.

The methods of manufacturing the sintering additives to coal charges from the vacuum residues of visbreaking tar, one of the most widespread and large-tonnage products, are considered. The starting raw material was subjected to deep vacuum distillation on a laboratory unit and thermal oxidation in a batch reactor. Experimental samples of sintering additives were obtained, and the possibility to produce sintering additives of petroleum origin on this basis was investigated. The physicochemical characteristics of the obtained products were determined; the possibility of their transportation, crushing, mixing and use instead of sintering coal grades in coal coking charges was assessed. A comparison of the obtained sintering additives was carried out for different production methods: an increase in the extent of tar conversion in visbreaking, deep vacuum distillation of the visbreaking residue, and oxidation of the visbreaking vacuum residue. The possibility of the industrial production of sintering additives from visbreaking residues was evaluated on the basis of research results.

Results of the studies of powder and structural composites (plates) based on low-density polyethylene (LDPE 15803-020 and LLDPE 6101RQ) and ultra-high molecular weight polyethylene (UHMWPE from Braskem company) and inorganic additives (SiC, TiO₂, CaCO₃, SiO₂) within concentration range 0.05-70 wt. % are presented. It is established that ultradispersed inorganic particles promote a decrease in the amount of the crystalline phase of polymers and an increase in wear resistance for the samples: UHMWPE (containing 7 wt. % SiC ( S _sp = 10 m²/g)) - by a factor of about 150; LDPE 15803-020 (20 wt. % SiC ( S _sp = 6-10 m²/g)) - by a factor of 2-2.5. For LLDPE 6101RQ samples with the low additive content (0.05-5 wt. % ТiО₂, SiO₂, CaCO₃), tensile strength increases by 7-24 %, мodulus of elasticity (along the axis) increases by a factor of 1.2-1.4, and relative elongation at fracture decreases within the range of 13.5-38.0 %. The maximal increase in tensile strength is observed for samples containing 20 wt. % SiO₂ and 50 wt. % ТiО₂ (by 38.5 and 43.6 %, respectively), while relative elongation at fracture decreases 2.8 and 3.9 times, and мodulus of elasticity increases by a factor of 1.9 and 2.0, respectively. Comparative data on the oxygen permeability of the plates, with different methods for the initial components’ mixing, show that samples prepared by mixing the polymer with inorganic additives in a mixer (the amount of additives 5 and 20 wt. %) gave a decrease in oxygen permeability within 5.6-11.2 %, while the samples prepared through mixing in a planetary mill activator, AGO-3, showed a decrease in oxygen permeability in the range of 16.8-28.7 %, compared to the original sample.

The mechanisms of the coagulation-based water purification using titanium-containing coagulants were studied. Investigation of colloidal systems formed during hydrolysis of traditional coagulants based on aluminium and iron compounds, as well as innovative and promising titanium-containing coagulants, was carried out. The surface characteristics (surface charge, specific surface area) of hydrolysis products of titanium compounds were determined under conditions close to those of the coagulation water purification. The surface characteristics of the products of hydrolysis of traditional and titanium coagulants were compared. It has been established that the hydrolysis products of titanium compounds carry a negative charge on their surface, and their surface that is extremely developed in comparison with traditional coagulants, which indirectly confirms their ability to adsorb pollutants. The sedimentation characteristics of the resulting hydrolysis products of various coagulants were studied. It was shown that the coagulation slimes formed as a result of the use of titanium-containing reagents have a larger flake size, which means they quickly settle to the bottom during settling. The increased efficiency of complex titanium-containing coagulants (Al-Ti) due to the phenomena of charge neutralization and nucleation on the surface of hydrolysis products of titanium compounds has been confirmed and scientifically substantiated. Evaluation of the efficiency of titanium-containing coagulants in the purification of drinking water from the Moscow water intake was carried out. It was found that in the purification of water from the surface water intake, titanium-containing reagents significantly exceeded traditional reagents in the effectiveness (a decrease in the content of suspended solids, colour index), and residual concentrations of titanium compounds in purified water meet the requirements of drinking water quality standards (0.1 mg/L). The sediments obtained with the use of titanium-containing coagulants were distinguished by an increased sedimentation rate and more readily gave up moisture during the filtration process, which would allow reduction of the dimensions of the treatment equipment.

Concentrations of organochlorine compounds (OCs) were determined, and comparative analysis of OCs in the bottom sediments of the Chernaya river, small lakes of the Baydar valley, the Sevastopol Bay and the Chernorechensky reservoir, sampled in 2008 and 2019-2020, was carried out. A noticeable difference in the levels of pollution with OCs in the river, lakes and the bay was detected. This concerns mainly such OCs as polychlorinated biphenyls (PCB), the content of which in sediments of the studied areas varied within a wide range - from 0.5 in lakes to 900 ng/g dry mass in the Sevastopol bay. Increased anthropogenic pressure on the river water area in the region of Baydar valley and in the estuary area has led to the formation of zones with the local maxima of the concentrations of PCB and organochlorine pesticides (1,1,1-trichloro-2,2-bis(chlorophenylethane), DDT) in the bottom sediments of the Chernaya river. In the Baydar valley, the sediments in lakes were on average less contaminated than river sediments, which is due to the isolation of lake ecosystems; they may be classified as non-polluted and weakly polluted. The maximal OCs concentrations were detected in the Sevastopol Bay. The ratio of DDT metabolites in the composition of organochlorine pesticides depended on redox conditions in bottom sediments: under anaerobic conditions of the Sevastopol Bay, DDT was transformed into DDD (1,1-dichloro-2,2-bis(4-chlorophenyl)ethane), under aerobic conditions in the river sediment - into DDE (1,1-dichloro-2,2-bis-(4-chlorophenyl)ethylene). Reconstruction of sedimentation geochronology using radiotracer methods shows that the variability of OCs content at different depths of fresh-water sediments depended on the temporally varying amounts of OCs income into the water areas but not on the natural conditions of sediment formation. According to estimates, at present, the runoff from the Chernaya river contributes not more than 14 % ∑DDT and 4 % ∑6PCB into the bottom sediments of the Sevastopol Bay.

The catalytic properties of ZSM-5 type zeolites modified with copper, zirconium and boron in the process of obtaining high-octane gasoline from the straight-run gasoline fraction of gas condensate have been studied in a flow-through installation at atmospheric pressure without hydrogen within the temperature range 350-430 °C. Cracking and aromatization of hydrocarbons mainly take place on non-modified HZSM-5 zeolite; with an increase in reaction temperature from 350 to 430 °C on HZSM-5, an increase in the content of aromatic hydrocarbons (from 10.8 to 16.9 mass %) and a decrease in the yield of liquid hydrocarbons (from 68.6 to 60.8 mass %) is observed. Modification of HZSM-5 zeolite with copper significantly changes the content of high-octane components in the catalyzate. An increase in copper concentration in HZSM-5 up to 2.0 mass % leads to an increase in the ability of the catalyst to provide isomerization and aromatization. At the optimum temperature (380 °C), the content of isoparaffinic and aromatic hydrocarbons in the catalyzate increases up to 36.8 and 24.6 mass %, respectively. An increase in the concentration of copper in HZSM-5 up to 3.0 mass % promotes an increase in the aromatization ability of the catalyst. Modification of the catalyst 2 % Cu/HZSM-5 with boron in the amount of 0.5-1.0 mass % has a small effect on its isomerization and aromatization properties, but significantly increases the yield of liquid products. It is found that the modification of the catalyst 2.0 % Cu-1.0 % B/HZSM-5 with zirconium in the amount of 0.5-1.5 mass % significantly increases the content of isoparaffinic hydrocarbons in the catalyzate (42.1-43.5 mass %). The highest activity is exhibited by the bimetallic catalyst consisting of 1.0 % Zr-2.0 % Cu-1.0 % B/HZSM-5, which allows obtaining the gasoline fraction with 88-94 octane number according to the research method. The addition of boron in the amount of 1.0 mass %, followed by the introduction of zirconium and copper, makes it possible to increase the duration of catalyst operation by up to 200 h. With respect to the content of isoparaffinic and aromatic hydrocarbons and benzene, the gasoline fraction corresponds to the Euro-4 and Euro-5 class. The possibility of refining low-octane straight-run gasoline fractions in the presence of a bimetallic catalyst under unconventional conditions without hydrogen supply to the reaction zone at atmospheric pressure is demonstrated.

As a result of sedimentation, suspended particles carry chemical pollution from the surface layer of water into bottom sediments, playing a significant role in waters’ self-purification from mercury. For the purpose of establishing the features of mercury distribution in the surface water of coastal and open-sea areas and concentrating it in the suspended matter, mercury concentrations were measured in water sampled in different seasons of the years 2018-2019 from the surface water layer of the Black Sea, and empirical dependencies of the parameters of mercury concentrating by the suspended matter on the seasons and depths of the water areas were determined. It is demonstrated that dissolved mercury forms dominated in the Black Sea during the period under investigation, regardless of the seasons. The concentration of dissolved mercury form in the water of the Black Sea varied from 10.0 to 130.0 ng/L, and the average concentration was 54.9 ng/L. The coefficient of mercury accumulation by suspended matter (K_ss) was determined, which varied within the range (0.01-3.33)•10⁶. The values K_ss > 10⁶ provide evidence of the high concentrating capacity of suspended matter in sea water and prevalence of sedimentation over other biogeochemical mechanisms of water self-purification. The formula for calculating the percentage pool of mercury in suspended matter was analysed. The values of the percentage pool of the suspended form of mercury were obtained, ranging from 3.2 to 75 % of the total mercury content in the surface water of the Black Sea for its coastal and open water areas in different seasons of the year.

Mumijo is a product of natural origin, composed of a complex mixture of organic compounds and exhibiting physiological activity in some cases. The Altai mumijo is widely known in Russia, but Tuvinian mumijo has been studied much less. The data on the location of mumijo in the Republic of Tyva, its elemental composition, isotopic composition of carbon, amino acid spectrum, and mineral formations associated with mumijo are presented. The investigated mumijo is a waste product of small rodents, which underwent aqua transfer, weathering and bacterial processing.

The carbon isotope composition analysis of 51 melliferous plants species of the Tomsk region, 35 samples of pollen load, 77 samples of honey and 36 samples of dead bees taken from different geographic regions of Russia was carried out. The stable carbon isotope ratios were measured to reveal the applicability of isotope ratio mass spectrometry to detect honey adulteration with sugar syrup and to determine the geographical origin. Seven adulterated honey samples were identified with the help of the method of honey adulteration detection based on comparison of the ¹³C/¹²C isotope ratio in honey sample and in the protein isolated from honey, which was an internal standard. Some differences in the carbon isotope composition (δ¹³C) are observed for honey samples from the Tomsk Region collected in 2019 and 2020, which points to the necessity of further studies of the influence of climatic conditions and honey harvesting season on the ratio of stable carbon isotopes in honey. Carbon isotope analysis demonstrated differences between honey samples differing from each other in geographical origin. Higher δ¹³C values are typical for honey samples from the European part of Russia and the Black Sea region. The δ¹³C values of honey from Siberian regions with a lower average temperature or higher air humidity are lower. For local areas, the “canopy effect” was revealed, in which the carbon isotope composition of the pollen load for forest ecosystems is depleted in ¹³С isotopes, compared to meadow ecosystems. Trophic enrichment values (Δ¹³С = 1.0±1.2 ‰) in the chain “pollen load - bee” were also determined.