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  • Designing of specialized fish food products with a reduced content of nitrogen extractives

    Alekseev, G. V.; Eliseeva, S. A.; Smolentseva, A. A. (2021)
    The authors consider the possibility of using low-value pelagic fish species in the diet of people with restrictions on the consumption of nitrogenous extractive substances including nucleic acids which are sources of purine base metabolism. The objects of the study were chopped mackerel fillets from boiled fish and chopped boiled fillets from raw fish, quick-frozen minced horse mackerel of industrial processing in a boiled form. The studies were carried out in accordance with the experimental plan in which the duration of the heat treatment and the temperature of the cooking medium were the variable factors. The technology of combined fish masses with the addition of functional plant components has been proposed. It has been established that the dynamics of dry matter losses and heat losses of fish fillets is determined by the duration of cooking. In terms of organoleptic characteristics boiled minced meat from raw mackerel fillets is significantly inferior to the organoleptic characteristics of minced meat from pre-boiled fillets. When comparing the data for frozen and freshly prepared mince from horse mackerel, it has been found that the loss of nucleic acids in industrially prepared minced meat is 4.6–13.1 % higher (T = 82 ± 2 and 98 ± 2 °C), the loss of nucleic acids by absolutely dry matter is higher by 11.3–5.8 %, mass – by 8.4–14.6 %. The content of the total amount of nucleic acids in industrial minced meat is 11.1 % lower than in freshly prepared minced meat. Obviously, in the process of preparing products for specialized purposes, including for preventive nutrition, it is preferable to use minced meat from boiled fish fillets.
  • Chemical composition of sea buckthorn (Hippophae rhamnoides L.) berry grown in the Chelyabinsk region

    Naumova, N. L. (2021)
    The most important phytonutrients of sea buckthorn (Hippophae rhamnoides L.) berry are carotenoids, flavonoids, anthocyanins, sugars, organic and amino acids, water and fat-soluble vitamins, tannins and pectin substances, phospholipids, macro- and microelements. In the Chelyabinsk region it is almost impossible to find well-groomed industrial plantings of sea buckthorn, since its main areas (600 hectares) are concentrated in amateur and home gardens. To form a healthy diet, it is important not only to ensure the safety of horticultural products, but also to raise the priority of signs that determine consumer demand, namely the quality and chemical composition of fruits, their saturation with the necessary micronutrients. While studying food and biologically active substances of sea buckthorn berries of the "Velikan" variety growing in different garden agrocenoses of the Chelyabinsk region it has been determined that sea buckthorn berries cultivated in the garden "Lokomotiv-1" (Chelyabinsk) contain more flavonoids (by 21.4 %), proteins (by 17.4 %), mineral elements – Al (in 5.3 times), V (3.4 times), Cu (3 times), Ti (2.4 times), Ca and Fe (1.9 times), Mn (1.5 times), in berries obtained in the garden "Dizelist-1" (Chelyabinsk region, Troitsk) contains more sugars (by 15.1 %), as well as Mo and Sr (2–2.3 times), Se (1.4 times), Cr (by 76.2 %), etc. In terms of Se content, the studied fruits exceed the clarke values by 4–6 times; in terms of Pb content, they turned out to be as close as possible to the upper limit of MPC according to the requirements of the Technical Regulations of the Customs Union. The study of the mineral composition of sea buckthorn is especially important in the context of the ecological disadvantage of the Chelyabinsk region due to the pollution of the environment with heavy metals.
  • New varieties of wheat, triticale and spelt grains: Comparative characteristics of milling properties

    Kandrokov, R. H.; Begeulov, M. S.; Tkach, A. N.; Igonin, V. N.; Porechnaya, E. S. (2021)
    Triticale and spelt grains are non-traditional types of plant raw materials that are promising for expanding the range of everyday products, healthy foods, as well as for the manufacture of food additives. A promising and relevant direction of scientific and practical research is the use of methods of biomechanical impact on the products of processing grain triticale and spelt grain in the form of flour, crumbs and bran to obtain food for general, functional and therapeutic purposes. The aim of the research is a comparative characteristic of the milling properties of new varieties of grain of wheat, triticale and spelt and the possibility of theit using for grinding into flour at existing grain processing enterprises. A comparative characteristic of the cereal-forming ability of new varieties of wheat, triticale and spelt has been carried out and it is revealed that the best cereal-forming ability belongs to the spelt grain of the "Gremme 2 U" variety, equal to 79.8 %, which is 4 % more than that of the wheat grain of the "Timiryazevskaya Jubilee" and 4.8 % of triticale grain of the "Timiryazevskaya 155" variety. It has been found that the highest flour yield under the same grinding regimes is obtained when grinding the grain of a new type of spelt "Gremme 2 U" amounted to 79.3 %. The largest amount of triticale flour of the highest grade T-60 is obtained from triticale grain of the "Timiryazevskaya 155" variety. The grain of wheat "Timiryazevskaya Jubilee" occupies an intermediate position both in terms of the total yield of flour and its quality compared to spelt and triticale. All three given new varieties of various crops have good flour-grinding properties and can be recommended for processing into high-quality bakery flour at flour mills when making grinding mixtures.
  • Substantiation of a rational method for drying granules in a fluidized bed and the hydrodynamic regime of their interaction with a fluidizing agent

    Nugmanova, A. A.; Aleksanyan, I. Yu.; Nugmanov, A. H.-H.; Maksimenko, Yu. A.; Khaybulov, R. A. (2021)
    Gluten is produced from wheat grains and is used in the food industry as an improver in flour baking properties. On the basis of a comparative analysis of the methods of dehydration of frozen granules of wheat gluten with a surface dry crust, a rational method of drying them in a fluidized bed has been selected. In the process of calculating units with a fluidized bed, its hydrodynamic parameters have been determined: loss of the pressure of the fluidizing agent; the speed at the transition of the bed from the state of rest to the pseudo-boiling mode; layer porosity; the rate of entrainment of particles in unrestricted conditions roughly corresponding to the rate of soaring, at which a single particle is in equilibrium in the gas flow. During the dewatering operation, the rate of entrainment of the granules varies; therefore, it is advisable to use the passing fluidization mode depending on the decrease in their moisture content. In the variant of the active hydrodynamic regime in the drying unit, the dehydration procedure is intensified without a noticeable decrease in the economic efficiency of its functioning and high quality indicators of the finished product with the given final moisture are provided, which is due to the specific conditions of contact of the granules with the coolant. For granules with a moisture content of 0.19 kg/kg, the values of hydrodynamic characteristics have been determined: the area of critical pseudo-boiling rates is 4.1–5.5 m/s; the carryover rate of the fines is 12.5–14.5 m/s. As a result of the study, the choice has been substantiated in favor of drying the studied granules in a fluidized bed due to the prevalence of its advantages over the dehydration of the object in drum dryers.
  • The study of biotechnological potential of Lactobacillus sakei LSK-103

    Nikiforova, A. P.; Khamagaeva, I. S. (2021)
    Lactic acid bacteria play an important role in the production of food. Bacterial cultures widely used in the food industry often have a set of characteristics that ensure the stability of the production. The biotechnological properties of Lactobacillus sakei LSK-103 have been studied in the present work. Lactobacillus sakei LSK-103 has shown high biochemical activity on MRS medium. It has been found that after 16 h of cultivation at the end of the exponential growth phase, the number of viable bacterial cells reaches 109 CFU/cm3. The study of the effect of different concentrations of sodium chloride on biomass accumulation has shown that Lactobacillus sakei LSK-103 is highly resistant to salt. Increase in NaCl concentration from 2 to 10 % leads to decrease in cell survival from 96.8 to 91.2 %, and in number of bacteria to 108 CFU/cm3. Morphological studies indicate that an increase in the concentration of sodium chloride in the medium is accompanied by cell cohesion, the formation of cell conglomerates. Cohesion intensifies intercellular contacts and increases the resistance of Lactobacillus sakei LSK-103 to osmotic stress. The high survival rate of Lactobacillus sakei LSK-103 has been shown in the presence of bile, phenol (0.4 %), high (pH 8.3) and low (pH 3.5) values of active acidity of the medium indicating its probiotic properties. The results of research have shown that the Lactobacillus sakei LSK-103 has high biotechnological potential and can be used as part of bacterial preparations for the production of fermented fish products.
  • Chemical and enzymatic destruction of chondroitin sulfate from Arctic skate

    Kuchina, Yu. A.; Konovalova, I. N.; Novikov, V. Yu.; Dolgopyatova, N. V.; Kuznetsov, V. Ya. (2021)
    Due to its biocompatibility with human and animal tissues, low toxicity, and biodegradability, chondroitin sulfate (CS) is of great interest for medicine. Since CS is used as a pharmaceutical preparation, its molecular weight and solubility determine the possibilities of its use. This work presents the results of studying the chemical and enzymatic destruction of CS macromolecules and its effect on the molecular weight, solubility and crystallinity degree of the polysaccharide. CS was obtained from the cartilaginous tissue of the Arctic skate (Amblyraja hyperborea). At the stage of cartilage tissue fermentolysis, the enzymes pancreatin, hepatopancreatin and protosubtil were used. The obtained CS samples were identified by IR spectroscopy. Enzymatic destruction of glycosidic bonds in cholesterol macromolecules was carried out with a 1 % solution of the enzyme hepatopancreatin, chemical destruction with hydrogen peroxide and hydrochloric acid. The CS content in the samples was determined by the Dische method. The chemical composition of CS samples was evaluated by standard methods. The average molecular weight (MW) was determined using high performance liquid chromatography and the nephelometric method. The crystallinity degree (CD) was determined by graphical processing of diffraction patterns obtained by X-ray phase analysis of CS samples. It was found that under the action of hepatopancreatin and hydrogen peroxide, deep destruction of chondroitin sulfate occurs, to the formation of low molecular weight and oligomeric fragments. Under conditions of acid destruction in 0.5 N HCl for 20 min the MW of chondroitin sulfate is reduced by 10 % compared to the initial one. Acid destruction causes a significant decrease in the CD of the CS samples. For CS samples not degraded in acid, the solubility in distilled water increases with decreasing MW and CD. The solubility of CS after acid destruction in the range of pH = 5–9 units is 99.0 ± 0.5 %. This high solubility is most likely explained by the significant content of the amorphous phase in the samples.
  • Evaluation of the effect of enzymatic hydrolyzate of the bursa of broiler chickens on cytotoxic activity and nonspecific immunity

    Kolberg, N. A; Leontieva, S. A.; Tikhonov, S. L.; Tikhonova, N. V.; Shikhalev, S. V.; Kirpikova, K. E. (2021)
    The use of biologically active substances of tissue origin for the creation of biologically active additives and immunomodulatory drugs is an important area of scientific research in the field of nutrition and pharmacology. The aim of the work is to evaluate the effect of enzymatic hydrolysate from the fabricium bag of broiler chickens on the cytotoxicity and nonspecific immunity of mice against the background of experimental salmonella infection using biotechnological methods. For the experiment, three equal experimental groups of white mongrel mice were formed. All laboratory animals were fed daily for seven days with enzymatic hydrolysate at a dose of 750 mg/kg (therapeutic dose), 150 mg/kg (0.2 therapeutic dose) and 3,750 mg/kg (five therapeutic doses). At the same time, the control group of animals received intragastric water in the same volume. 24 hours after the last intake of the enzymatic hydrolysate, the animals were intraperitoneally infected with a culture of Salmonella enteritidis 92. The study reveals the absence of cytotoxic properties and impaired cell viability in cultures L929, J774.1A, HeLa S3, K562, and HST116 against the background of exposure to various concentrations of enzymatic hydrolysate from 0.02 to 10 mg/ml. It should be noted that there is a pronounced cytotoxic effect on MCF-7 tumor cells of the concentration of enzymatic hydrolysate in culture of 5 and 10 mg/ml, which suggests the possibility of using enzymatic hydrolysate for the prevention of tumor diseases. As a result of the experiment, it has been proved that the administration of enzymatic hydrolysate to mice increased the LD50 index and the survival rate of mice infected with the culture of the causative agent of salmonellosis by 1.5 times. Based on the conducted studies, it has been shown that the enzymatic hydrolysate of the lymphoid tissue of broiler chickens does not violate the viability of mammalian cells and does not exhibit cytotoxic properties on the metabolism of healthy mammalian cells, which indicates its safety. In an experiment on mice, the effect of enzymatic hydrolysate of the fabricium bag of broiler chickens on the activation of nonspecific immunity against salmonella infection has been revealed.
  • Development of a functional bread technology based on a grain baking mixture

    Alekhina, N. N. (2021)
    One of the priority areas for developing the food industry is to increase the production of functional food products. When developing the latter, fruit and berry processing products, grain baking mixes are used. At the same time, there are no baking mixes with the use of bioactivated wheat, characterized by an increased content of macro- and micronutrients, antioxidants, and a reduced amount of phytin. However, the preparation of grain bread based on a baking mixture of bioactivated wheat crushed by the disintegration wave method with a moisture content of 10.0 ± 0.5 % led to the production of products with a sticky, strongly jamming crumb. The aim of the research was to develop a baking mixture of bioactivated wheat and functional grain bread of improved quality based on it. At the first stage of the research, the composition of the baking mixture based on bioactivated wheat grain was selected to obtain the best quality product, at the second stage, the chemical composition of bread was evaluated based on the developed baking mixture. The change in the properties of the dough during fermentation, the quality indicators of bread after 20 hours of storage and its chemical composition were evaluated in accordance with the methods specified in the current standards. The best properties of the dough and the quality of the bread have been observed in a sample obtained on the basis of a baking mixture, in 100 g of which 75 % of the grain products are dry bioactivated wheat crushed by the disintergation-wave method, and 25 % – baking wheat flour of the first grade. As a result of the assessment of the chemical composition of the developed product, it has been found that it belongs to functional food products. The preparation of grain bread using this technology will also allow us to solve one of the tasks of the state policy in the field of healthy nutrition aimed at increasing the production of functional products.
  • Numerical simulation of the thermal regime of an underground spent fuel storage facility (built-in structure variant)

    Amosov, P. V. (2021)
    The results of a numerical simulation of the thermal regime of an underground facility for long-term storage of spent nuclear fuel in a built-in reinforced concrete structure are presented. Two computer models were constructed in a three-dimensional formulation in the COMSOL programme. The first model is based on the incompressible fluid approximation, while the second model is based on the "incompressible ideal gas" approximation. The mathematical basis of models: the continuity equation, Navier – Stokes equations averaged by Reynolds, the standard (k – ?) turbulence model, and the general heat transfer equation. Consideration of mixed convection conditions is implemented in the "incompressible ideal gas" approximation, where the air density is a function of temperature only. The most thermally stressful arrangement of spent fuel placement is investigated: U-Zr – defective – U-Be. The air rate is varied in the range from 21 to 0.656 m3/s. Numerical experiments were performed for up to 5 years of fuel storage. The principal difference between the non-stationary structure of the velocity fields predicted in the "incompressible ideal gas" model and the "frozen" picture of the aerodynamic parameters in the incompressible fluid model is emphasized. It is shown that the requirements for exceeding the temperature limit values are met when the object operates under conservative ventilation conditions (rate 0.656 m3/s) with a minimum of costs for organizing ventilation. The dynamics of heat flows directed into the rock mass through the base and from the surface of the built-in structure of the U-Zr fuel compartment to the air environment are analyzed. The predominance of the heat flow from the surface of the structure and the different times when the curves of the heat flow dynamics reach their maximum values are noted. The heat flow to the array reaches its maximum significantly faster than to the air.
  • Natural risks and monitoring systems: Case study of the mining-industrial heritage objects of Karelia (Ruskeala Mining Park), Russia

    Shekov, V. A. (2021)
    Mine workings (open and underground) abandoned during the production process become part of the environment. These objects begin to degrade in accordance with ordinary processes occurring in nature. However, such developments are often of historical value and therefore become tourist sites. They pose a serious threat to the health and life of people visiting these tourist sites, if such workings were not initially processed to safe conditions. The paper considers an example of such an object – a marble quarry with elements of underground caves – the Ruskeala marble deposit, located in Karelia. In the middle of the XX century, it was abandoned, today the "Main" quarry is a monument of the historical and cultural (mining-industrial) heritage of the Republic of Karelia. Ruskeala Mining Park has collected all the risks of degradation inherent in such a natural site. The paper has proposed solutions for monitoring the sustainability of underground objects used as museum exhibits to ensure the safety of tourists visiting them.
  • Seasonal variability of sulfate ions in the Volga River water

    Seleznev, V. A. (2021)
    In the Volga River water, sulfate ions rank second among the main anions in terms of their contribution to water mineralization. To study the seasonal variability of sulfate concentration, an analysis of long-term data of hydrological and hydrochemical observations obtained on the River Volga (in the outlet section of the Kuibyshev reservoir) has been carried out. For the period of 2001–2018 the average annual water consumption in the dam section varied in the range of 6.2–9.0 thousand m3/s, the average annual concentration of sulfates was 55 mg/dm3, the highest – 64 mg/dm3, and the lowest – 45 mg/dm3. The content of sulfates in the reservoir is formed mainly under the influence of the Volga River water coming from the Cheboksary reservoir and the Kama River water coming from the Nizhnekamsk reservoir. The sulfate content is characterized by significant seasonal variability. During the winter low-water period, the highest concentrations of sulfates were observed with a maximum in April, before the beginning of the spring flood (67 mg/dm3). During the flood, the content of sulfates decreased, reaching the lowest values during the summer low-water period in August (44 mg/dm3), and then, from September, the concentration of sulfates gradually increased, reaching 57 mg/dm3 at the beginning of the winter low-water period. Over a long-term observation period, the amplitude of sulfate fluctuations was 34–87 mg/dm3, and its value depended on the water content of a particular year. In dry years, the concentration of sulfates in the water increased, and in dry years, it decreased. In the seasonal context, the main differences in sulfate concentrations in dry and high-water years occurred during the spring flood and winter low-water period, and during the summer – autumn low-water period, the differences became minimal.
  • Analysis of atmospheric emissions in Murmansk and their relationship with pollution of urban lakes

    Postevaya, M. A.; Slukovskii, Z. I. (2021)
    The main sources of anthropogenic emissions into the atmosphere of Murmansk are emissions from thermal power plants and boiler houses operating on fuel oil. As a result of the analysis of the dynamics of pollutant emissions from stationary anthropogenic sources for the period 1997–2019 it has been established that the level of air pollution is assessed as low; there is a tendency towards a decrease in gross emissions from stationary sources. The main pollutants from thermal power plants are sulfur dioxide, nitrogen oxides, carbon monoxide, formaldehyde, and benzo(a)pyrene. Together with gaseous and liquid substances, fuel oil ash and products of incomplete underburning of fuel, which include heavy metals V, Ni, Cr, Pb, Fe, Sn, enter the atmospheric air. Technogenic compounds of heavy metals and other pollutants from the enterprises of the power unit, falling out with dust or precipitation on the surface and catchment areas of lakes, affect the formation of the chemical composition of surface soils, waters and bottom sediments of water bodies. This is reflected in an increase in the concentration of heavy metals (in particular, V and Ni) in the water and bottom sediments of the lakes of Murmansk in comparison with the background values.
  • Destructive activity of hydrocarbon-oxidizing micromycetes extracted from the substrates of the coastal areas, the Barents and White Seas

    Isakova, E. A.; Korneykova, M. V. (2021)
    We analyzed the hydrocarbon-oxidizing activity of 33 micromycetes strains isolated from water and soils of the White Sea and Barents Sea coastal territories. The microscopic fungi studied were represented by the following genera: Acremonium, Aspergillus, Meyerozyma, Oidiodendron, Paradendryphiella, Penicillium, Pseudoqymnoascus, Tolypocladium, Trichoderma, Sarocladium, Talaromyces, Umbelopsis. Hydrocarbon-oxidizing activity of fungi was carried out in a laboratory experiment for two time periods: 14 and 28 days. The residual concentration of oil hydrocarbons in the medium was determined by the infrared spectrometry method. We revealed that micromycetes had different oil-destructive activity. The decrease in oil content for the strains over 14 days ranged from 11 to 83 %. Tolypocladium inflatum st.1, T. inflatum st.2, Penicillium thomii, Meyerozyma guilliermondii, P. simplicissimum, P. camemberti, P. solitum and Trichoderma minutisporum strains had the greatest oil destructive activity, reducing the concentration in the medium by 57–83 %. These micromycetes were isolated from coastal substrates, the content of oil products in which did not exceed the MPC. We found that some individual strains of microscopic fungi had high oil-destructive activity for a longer period of time: Tolypocladium cylindrosporum reduced the content of oil hydrocarbons for 28 days by 95 %. No clear relationship between the fungal biomass and the degree of decomposition of oil products was found, but some tolerant species of micromycetes can actively decompose oil hydrocarbons without significantly increasing their biomass. The identified active strains of hydrocarbon-oxidizing micromycetes can be used to create biopreparations with the prospect of their further use for bioremediation of oil spills in the northern marine ecosystems.
  • U-Pb age and trace elements composition of titanite from granites of Belokurikhinsky massif, Gorny Altai

    Skublov, S. G.; Mamykina, M. E.; Rizvanova, N. G. (2021)
    As a result of isotope-geochemical study, the age data (U-Pb method, ID-TIMS) of titanite from the first phase granites of the Belokurikhinsky granite massif, Gorny Altai, were obtained for the first time. The concordant value of the titanite age of 255 ± 2 Ma coincides within the margin of error with the previously published results of dating micas from granites of the second and third phases of the Belokurikha massif by the Ar-Ar method (250 ± 3 Ma). At the same time, the results of dating differ significantly from the previously published age values for the granites of the Belokurikha massif (232 ± 5 Ma, U-Pb method for the monofraction of zircon grains; 245 ± 8 Ma, Rb-Sr method for the whole rocks). Therefore, there is every reason to narrow the time interval of the formation of the Belokurikha granite massif to 255–250 Ma. The study of the trace element composition of titanite by SIMS demonstrated their zonal structure. The central part of the titanite grain differs from the rim by a noticeably higher content of REE, Cr, Y, and Nb. The content of V, Zr and Ba decreases to a lesser extent towards the rim, the content of Sr and U remains constant. At the same time, the REE distribution spectra in the central and rim parts are conformal to each other, having a convex spectrum for LREE and a concave one for HREE. Titanite is characterized by a negative Eu-anomaly, the depth of which decreases to the rim of the grain. A negative Eu-anomaly indicates the co-crystallization of titanite and plagioclase. The REE distribution spectra in titanite from the Belokurikha massif correspond to the characteristics of a typical magmatic titanite from granitoids and differ significantly from the distribution spectra in metamorphic titanite.
  • Registration of avalanches in the Khibiny Mountains by the geophysical methods

    Fedorov, I. S.; Fedorov, A. V.; Asming, V. E. (2021)
    In the winter months of 2018–2020 the Kola Branch of the Unified Geophysical Service RAS conducted experiments on the joint registration of avalanches in the Khibiny mountain range using seismic and infrasonic sensors during work on the forced descent of the snow mass. The aim of the experiments is to assess the possibility of avalanche detection using the geophysical methods. The lack of representative statistics on the frequency and regularity of avalanches is the reason for the relevance of developing methods of their remote registration. The difficulty of registering avalanches is due to their occurrence often in hard-to-reach areas and in poor visibility conditions. To record signals generated by avalanches, different configurations of infrasound panels consisting of three spatially separated sensors (MPA 201 or Hyperion IFS-4000 microbarographs) and a portable seismic station Guralp CMG-6TD were used. As a result of the experiments, infrasound recordings were obtained at different distances from the avalanche source. The infrasound group recordings collected from the experiments were processed using an automatic detector implementing amplitude and cross-correlation signal detection methods. The spectral composition of the recordings and their characteristic appearance were analyzed. Avalanche-induced signals are characterized by long duration and changes in azimuth to the source. The dominant frequencies of the signal lie in the region of 1–10 Hz. Conclusions are made about the insufficient sensitivity of the seismic method when the seismometer is located at a distance of the first kilometers from the avalanche source, as well as the high applicability of the infrasound method for recording the facts of avalanches. The results obtained will make it possible to develop a methodology for automatic detection of signals generated by avalanches using the data of infrasound registration. This is the necessary basis for building a system for continuous monitoring of avalanche activity.
  • Petrographic structures: Khibiny ijolites and urtites

    Voytekhovsky, Yu. L.; Zakharova, A. A. (2021)
    In addition to the standard description of the structures and textures of crystalline rocks the mathematical approaches have been proposed based on a rigorous determination of the petrographic structure through the probabilities of binary intergrain contacts. In general, the petrographic structure is defined as an invariant aspect of rock organization, algebraically expressed by the canonical diagonal form of the symmetric Pij matrix and geometrically visualized by structural indicatrices – surfaces of the 2nd order. The agreed nomenclature of possible petrographic structures for an n-mineral rock is simple: the symbol Snm means that there are exactly m positive numbers in the canonical diagonal form of the Pij matrix. New types of barycentric diagrams have been proposed. To describe the massive texture, the concept of Hardy – Weinberg equilibrium has been proposed. This boundary classifies barycentric diagrams into areas within which canonical types of Рij matrices and topological types of structural indicatrices are preserved. The change in the organization of the rock within a type is quantitative, the transition from one type to another means structural restructuring. The methods are used to describe ijolites and urtites of the Khibiny massif, the Kola Peninsula. In the modern taxonomy of rocks, the boundaries between them are mostly conditional and are drawn according to the contents of rock-forming minerals, for example, between ijolites and urtites – according to the contents of nepheline and pyroxene. The strict definition of the petrographic structure proposed by the authors makes it possible to introduce into petrography the constitutional principle (structure + composition), which is successfully acting in mineralogy.
  • Intertidal community of fucoid seaweeds in the Yarnyshnaya Bay, the Barents Sea

    Kapkov, V. I.; Shoshina, E. V. (2021)
    The specific and spatial structure of benthic algal community on the littoral zone in the east area of Murman coast of the Barents Sea (69°11'78''N, 36°04'38''E) has been studied in the conditions of anthropogenic influence absence. As a material for studying indicators of fucoid community and populations of dominating species in connection with habitats own long-term seasonal observations and data of scientific expeditions of 1994–2017 have served. The species composition of littoral phytocenosis consists of 39 species including 18 brown, 9 red and 12 green seaweeds, with prevalence on number of annual and seasonal species, on a biomass – perennials. Ecological factors influence essentially on seaweed distribution in different sites of the littoral zone. The major abiotic factors are presence of firm substratum, surf and storms, ice motion. Seaweed littoral community had multi-level structure, in which the basic layer was occupied by brown seaweeds with numerous litophytes and epiphytes under beds and on thallus of dominant species. The community algal biomass in the littoral zone was from 2.8 ± 0.6 up to 17.7 ± 2.9 kg/m? and depended on the species structure, substratum for benthic seaweeds, surf and tides. The biomass and density of fucoid seaweeds varied over a wide range in different biotopes under a natural rigid press of seasonal changes of environmental factors (temperature, surfs, storms) during tides and under natural damages of littoral community in the arctic region. As a whole littoral fucoid phytocenosis of the bay could be considered as an example of adaptation of seaweeds populations to the conditions of the northern seas. The received results could be useful for estimating ecological status of coastal ecosystem, at stock assessment of commercial seaweeds and for algal aquaculture development in the Barents Sea.
  • Chemical amelioration of nepheline sands using sewage sludge from a regional wastewater treatment plant

    Gorbacheva, T. T.; Lusis, A. V.; Ivanova, L. A. (2021)
    The studies on the use of municipal wastewater sludge as an unconventional chemical ameliorant with a fertilizing effect were carried out on ore dressing waste ("tailings") of the apatite-nepheline plant ANOF-2 KF JSC "Apatit" with a predominance of nepheline sands in their composition. The tailings dump is included in the list of objects of accumulated environmental damage in the region, but due to its rich mineral composition, it is recognized as a technogenic deposit subject to conservation for the prospect of obtaining apatite, nepheline, sphene, aegirine and titanomagnetite concentrates. In the work, the method of phytotesting of soil irrigated with unfiltered rainwater with fragmentary application of sewage sludge of a regional wastewater treatment plant enterprise has been applied. The experiments have been carried out on a single-species seed recommended for reclamation of disturbed territories in the northern regions. During the formation of a sown phytocenosis from meadow timothy (Phleum pratense L.) on nepheline sands, the stimulating effect of sewage sludge on the nutrient regime of the soil is confirmed. After phytoextraction (at the end of the experiment), it retains a high residual pool of basic nutrients (N, P, K), which indicates a prolonged action of sewage sludge. To confirm the effect obtained in laboratory conditions, a field experiment has been laid at the ANOF-2 reserve tailing dump in 2019, observations are continuing.
  • Sulfur isotope signatures of sulfides from the Khibina and Lovozero massifs (Kola Alkaline Province, Fennoscandian Shield)

    Huber, M.; Mokrushin, A. V. (2021)
    The sulfur isotope geochemistry of the Khibina and Lovozero agpaitic massifs provides an opportunity to understand the role of plume-lithosphere interaction processes responsible for the Paleozoic alkaline igneous activity in the north-eastern part of the Fennoscandian Shield. The stable sulfur isotope δ 34S analysis using triple collector isotope ratio mass spectrometer (IRMS) has been carried out on the pentlandite, chalcopyrite and pyrite from nepheline syenites. The δ 34S values for pentlandite from Khibina rocks range from +0.69 to +2.06 ‰ relative to the Vienna Canyon Diablo Troillite standard (VCDT), and the pyrite has significantly higher δ 34S values up to +4.92 ‰ VCDT. The pentlandite from the Lovozero samples has value +1.48 ‰ VCDT, δ 34S values of chalcopyrite is +2.85 ‰ VCDT. The maximum positive δ 34S values are obtained for Lovozero pyrite, which vary from +5.41 to +6.30 ‰ VCDT. Comparison of sulfur-geochemical features of Khibina and Lovozero nepheline syenite with δ 34S data for the carbonatites from the Khibina, Sallanlatvi, Seblyavr, Vuoriyarvi, Salmagora and Kovdor massifs show later carbonatite formation relatively to associated alkaline rocks. Geochemical sulfur isotope δ 34S investigations emphasizes that parental magmas of the Khibina and Lovozero alkaline massifs were derived from a metasomatized subcontinental lithospheric mantle (SCLM). We suggest that high-?34S signature on the SCLM (δ 34S of +1 to +6 ‰ VCDT) can be explained by subduction of the high-δ 34S Archaean crust.
  • Lithological characteristics of modern sediments in the southwestern part of the Kara Sea shelf

    Chikirev, I. V.; Tolstobrov, D. S.; Sorokhtin, N. O.; Nikiforov, S. L.; Meluzov, A. A.; Ananiev, R. A.; Dmitrevsky, N. N. (2021)
    In August – September 2020, during cruise 49 of the R/V Akademik Nikolay Strakhov, comprehensive geological, geophysical, hydroacoustic, geomorphological and hydrophysical research studies of the western segment of the Arctic zone within the Pechora and Kara Seas began in 2018–2019 were continued. As previously, the work was aimed at mapping the relief and modern sediments in order to assess the possible negative consequences of changes in natural conditions on the Arctic coast of the Russian Federation. The main purpose of the research was to assess the evolution of natural environments within the southwestern part of the Kara Sea shelf in connection with the observed global climate change in the Arctic, as well as with the expected increase in anthropogenic load on the Arctic shelf due to the development of oil and combustible natural gas fields. Bottom grab and a shock ground tube were used to obtain samples of recent sediments of the Kara Sea. The sampling sites were determined based on the analysis of data from bathymetric bottom survey and continuous seismic profiling. During the research, the boundaries of the distribution of various facies of bottom sediments within the southwestern part of the Kara Sea shelf have been clarified. The main feature of the modern bottom sediments in the southwestern part of the Kara Sea shelf is a wide areal distribution of thin facies – pelitic muds. Along the eastern and southern coasts of the Archipelago Novaya Zemlya, a distribution zone of iceberg sediments with a width of at least 150 km has been established. The formation of icebergs should be associated with the movement of the Novaya Zemlya cover glacier, formed 30–20 thousand years ago during the Sartan Ice Age. As the studies have shown, the general Holocene transgression in the Kara Sea was periodically replaced by short regressions, at least in the southwestern part of the basin.

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