Home – Home – Jornals – Advanced Search

A problem of penetration of a rigid impactor into a semi-infinite target is solved analytically to determine the dependence of the angle of expansion of ejection particles (ejection angle) on the penetration depth of the impactor. The problem is considered under the assumption of a plane deformed state of the target material. The mechanical properties of the target material are described using the hypothesis that the target material is incompressible and ideally plastic. An equation of motion (penetration) of the impactor on the basis of energy balance is obtained. The angles of ejection are determined from the condition of minimum power of internal forces. It is established that, in the case of impactor penetration to an infinite depth, the limiting value of the ejection angle (elevation angle) is approximately 84 ^°C.

The relationship between climate warming and processes occurring in communities and populations of terrestrial small mammals, reptiles, amphibians, and arthropods is considered. The studies were conduct-ed at the Yenisei ecological station “Mirnoe” of the A. N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences. The dynamics of climatic changes are shown on the basis of data from seven weather stations located along an almost thousand-kilometer stretch of the Yenisei River valley. The maximum temperature increase for the period from 1972 to 2020 was noted in the spring months, and the more northern the station is, the stronger these changes are manifested. In the XXI century cyclic type of small mammal population dynamics, which was noted for this area earlier, changed to fluctuating one. The number of small mammals in tenth century was lower than in XX century. At the same time, a significant decrease was noted mainly for species whose origin is connected with Siberia. Some new species were recorded for the first time in the territory of the Yenisei ecological station. The banc vole (Clethrionomys glareolus) and the taiga mite (Ixodes persulcatus) appeared on the right bank of the Yenisei, and the gray toad (Bufo bufo) appeared on both banks.

The aim of this study is to identify ecological and phytocenotic features and factors of differentiation of plant communities with Heracleum sosnowskyi Manden. in the Kursk region. This region is located on the southern border of the secondary area of this species in the European part of Russia. Plant communi-ties with Heracleum sosnowskyi in the study area are represented by 4 syntaxons. To identify of ecological patterns of their organization, we used the analysis of the composition of differential species and species with the greatest activity, the identification of differences in the ecological regimes of their habitats, and the ordination analysis of relevйs. Each syntaxon differs from the others in a number of environmental factors and is characterized by a group of species with similar environmental requirements. Рredominance of ruderal and eurytopic species in communities and increase of similarity of their floristic composition are manifestations of the negative impact of the distribution of Heracleum sosnowskyi on the vegetation cover. The greatest similarity of coenofloras is found between the derivative communities Heracleum sosnowskyi [Agropyretalia intermedio – repentis] and the association Urtico dioicae – Heracleetum sosnowskyi. Their phytocoenoses represent successive stages of vegetation cover change under the influence of the invader. As a result of the spread of hogweed, the strongest changes occurred in the aboriginal communities, in place of which the phytocenoses of these syntaxons were formed. In communities where Heracleum sosnowskyi forms variants of associations Rudbeckio laciniatae – Solidaginetum canadensis and Chelidonio – Aceretum negundi, the floristic composition and ecological conditions changed slightly compared to typical communities of these syntaxons due to the presence of other invasive species.

The round goby is a small demersal fish considered one of the top invasive fish species. Having settled far beyond its native Ponto-Caspian region, the round goby currently inhabit the basins of the Baltic and North Seas, as well as the Great Lakes of North America. Since 2005, the species has been increasingly occurred in the eastern part of the Baltic Sea - the Gulf of Finland, where one of its northernmost populations was founded. The study is focused on studying the morphological differentiation of the round goby from geographically distant parts of the Gulf of Finland in order to assess the heterogeneity of this population and to suggest the most probable ways of the species penetration and dispersal there. Four samples were compared in 5 meristic and 35 morphometric traits. The traits characterized the number of finrays and rows of scales along the body, the shape of the body and head, and the position and shape of the fins. The comparison was carried out using indices, parametric and nonparametric tests, factorial, cluster analysis and multivariate scaling. Round goby samples collected at a distance of 40 to 270 km significantly differed in body shape, position and size of fins, while other characters were less prominently different between locations. The round goby from the western part of the gulf was the most different from goby of its eastern part, where morphological differentiation between locations was also observed. The results of the study assume the existence of separate round goby populations in the Gulf of Finland, with development of morphological features, associated with local habitat conditions, and the limited migrations of the species within the gulf. On the basis of the results obtained, we suggested independent introduction of the round goby into the western and eastern parts of the Gulf of Finland of the Baltic Sea.

The ecological patterns of landscape differentiation of the fauna and bird population of the northern taiga of Central Siberia at altitudes of 100-1000 m a. s. l. have been analyzed. m. In 2002-2020 surveyed flat right bank of the river basin Lena and low-mountain areas of the Putorana Plateau and Vilyui Plateau. The route accounting method was used on transects of unlimited width. The commonality of the taxonomic structure and species composition of the nesting avifauna, numbering 156 species, is high. A number of species ( n = 14) were first recorded nesting at a distance of 100-250 km from the known boundaries of their ranges. The taxonomic structure of the nesting avifauna corresponds to the zonal and landscape features of the taiga of North Asia with the dominance of species from the orders of passeriformes, shorebirds, anseriformes, falconiformes, totaling 83 %. The avifauna of the northern taiga of Central Siberia is formed in a system of common zonal and altitudinal-belt patterns, unites species ecologically associated with forest and shrub vegetation, meadow, water, and mountain habitats. The most significant in the formation of the avifauna are the species of the Siberian (40 %) fauna type, boreal and boreal-hypoarctic zonal-landscape groups (41 %). The average population density of birds in the northern taiga larch forests is 261 ind./kmІ, in aquatic-semiaquatic habitats 8.5 ind./1 km of coastline. The bird population of larch forests is dominated numerically by the kuksha, willow, talovka, zarnichka, brown thrush, finch, common tap dance, baby bunting. Among the dominants of water and semiaquatic habitats there are 17 species, incl. wigeon, common teal, common tern, carrier, fifi, haley, glaucous gull, arctic tern.

The species composition and quantitative characteristics of the zoobenthos of Lake Pyasino and rivers flowing into it after the diesel spill have been analyzed. The production of zoobenthos and potential production of benthivorous fish in Lake Pyasino have been calculated. A small number of zoobenthos species, low values of abundance and biomass were revealed. In the Bezymyanny stream, the mouth of the Daldykan and Ambarnaya rivers, oligochaetes Limnodrilus hoffmeisteri Claparede and Tubifex tubifex (O. F. Muller) dominated in zoobenthos abundance and biomass. In Lake Pyasino and the Pyasina River outflow, larvae of caddis flies, chironomids, stoneflies, and amphipods prevailed. In the area of deep-water silted station of Lake Pyasino, oligochaetes L. hoffmeisteri developed, the proportion of which in the benthofauna at this station (40 and 79 % of the total biomass and abundance respectively) was maximal. Amphipod Monoporeia affinis (Lindstrцm) dominated in biomass at this station. A decrease in chironomid diversity, an increase in the proportion of polysaprobic oligochaetes, and lower values of the Shannon index in Lake Pyasino in 2020 compared to 1992 were noted. The low abundance (2181 ± 2048 ind./m²) and biomass (2.01 ± 1.85 g/m²) of zoobenthos in the lake resulted in low values of zoobenthos production and potential production of benthivores fish (3 kg/ha per season). Based on the state of zoobenthos, improvement of water quality has been observed from river sections exposed to the oil spill to the lake and the outflow of the River Pyasina.

Data on the state of stands and undergrowth of the main forest-forming species at the Karadag Nature Reserve in oak forests of downy oak (Quercus pubescens) and sessile oak (Q. petraea) under conditions of super-high density of European roe deer (Capreolus capreolus) are presented. The exponential growth in number of roe deer in the reserve, which has been observed since its creation (1979), led to an increase in its number by 2016 to 750 individuals and a density of up to 437 individuals per 1000 ha, which is 10 times higher than the norm. At the same time the level of damaged sessile oak undergrowth increased from 7.6 to 88.9 %, and downy oak - from 8.4 to 83.7 %. A decrease to an absolute minimum in number of mid and complete absence of big undergrowth of both sessile oak and pubescent oak took place. Alignment of tree species in abundance (estimated by the Berger-Parker index) is 1.20 for sessile oak stands and 1.18 for downy oak stands, and undergrowth in these stands is 3.0 and 1.6 respectively. At the Primorskoye Forestry located next to the reserve, relatively favorable in terms of the density of roe deer (37 individuals per 1 thousand ha), damage to the undergrowth of the main species was 5.5 % in sessile oak groves and 7.2 % in downy oak groves. Alignment of tree species in oak forests at the Primorskoye Forestry in abundance is 1.25 for sessile oak and 1.54 for downy oak, and for undergrowth - 2.15 and 2.11 respectively. Being based on the totality of the obtained data it was concluded that even under conditions of a super-high density of ungulates oak forests of the Karadag Reserve retain the possibility of renewal due to an increase in the density of small undergrowth (sessile oak groves) and alignment of undergrowth (downy oak groves). Regarding to the renewal of the main species the excessive number of roe deer in the reserve plays a negative role, and respectively biodiversity in terms of the alignment of tree species undergrowth in terms of abundance it plays a positive role.

Dechlorination of the hydroxy derivatives of polychlorinated biphenyls in coal tar pitch has been carried out. It is shown that the heat treatment of polychlorinated biphenyl congener mixtures and hydroxy derivatives of polychlorobiphenyls in toluene-insoluble substances of coal tar pitch involves hydrodechlorination of chloroarenes and their hydroxy derivatives with hydrogen transfer from coal tar pitch compounds. The major products of these reactions are the products of condensation with coal tar pitch compounds, as well as congeners of polychlorinated biphenyls and hydroxyl derivatives of polychlorobiphenyls a smaller number of chlorine atoms.

The results of laboratory studies on the additional treatment of model wastewater from pharmaceutical production with the help of the combined effect of UV radiation and hydrogen peroxide are presented. Literature data on the existing purification technological schemes were analyzed, with the determination of their main advantages and disadvantages. Experimental results were obtained on the treatment of model solutions of acetylsalicylic acid, tetracycline and sulfadimezin after passing through three stages of purification: photooxidation, coagulation, and sorption. The values of chemical oxygen demand (COD) and concentration of active pharmaceutical ingredients (API) were determined. The combined action of photooxidation and hydrogen peroxide makes it possible to achieve purification efficiency up to 80 % for COD and up to 99 % for API. A technological scheme for the treatment of pharmaceutical wastewater is proposed.

Hematite nanoparticles (23-150 nm) were obtained and dispersed in a hydrocarbon medium. The introduction of hematite nanoparticles at a concentration of 0.02 to 0.30 mass % into the oil residue during thermolysis allows increasing the yield of gasoline and reducing the yield of resins. The role of hematite is explained by its ability to selectively sorb resins and asphaltenes on its surface.