Северный (Арктический) федеральный университет имени М.В.Ломоносова

Seed quality and seed germination are the major indicators determining the success of regeneration and structure in natural forest ecosystems. This study focuses on problems associated with seed quality and seed germination under air pollution impacts in the surrounding forest ecosystems of Ulaanbaatar city of Mongolia. The objectives were to test whether there was any negative effect of air pollutants on the site index, and to analyze the relationship between seed quality and distance from the city center (maximum pollution). The study was carried out in natural larch forests (Larix sibirica Ledeb.) growing in the vicinity of the capital of Mongolia. A total of eight 100×100 m (1 ha) sample plots were laid out using completely randomized sampling design along the main wind direction. Remoteness from the city center was 10, 15, 20 and 30 km both to the north and to the south. Results showed a high variation in stand mean height (p > 0.001) and diameter (p > 0.001) among selected forest areas. In general, all sampled forests belonged to bonitet / quality classes III, IV and V, which are considered as relatively poor growing conditions in terms of site index. Therefore, greater site index and seed quality were observed in the most distant locations from the city center, and contrary, the poorest seed quality was detected in locations close to the city center. This emphasizes that forests growing close to pollution sources exist with a potential risk of degradation, and their reproductive organs are more sensitive to the effects of pollutants. For citation: Udval B., Gerelbaatar S., Dashzeveg Ts., Lobanov A.I. Seed Quality of Larix sibirica Ledeb. Depending on the Distance between Forest Areas and Pollution Sources around Ulaanbaatar City of Mongolia. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 4, pp. 23–35. DOI: 10.37482/0536-1036-2021-4-23-35 Acknowledgments: This research was carried out within the framework of the project “Study of Forest Ecosystems in the Green zone of Ulaanbaatar city” and funded by the Foundation for Science and echnology. We also thank John Stanturf for the language improvement of this article.
Качество семян и их всхожесть являются главными показателями, определяющими успех восстановления и структуру естественных лесных экосистем. Основное внимание уделено проблемам, связанным с качеством семян лиственницы сибирской (Larix sibirica Ledeb.) и ее прорастанием в условиях загрязнения воздуха в окружающих лесных экосистемах города Улан-Батора. Цель работы – выявление влияния загрязнения воздуха на индекс участка и анализ взаимосвязи качества семян и расстояния от лесного участка до центра города (максимума загрязнения). Исследования проведены в естественных лиственничниках, произрастающих в окрестностях столицы Монголии. Всего было заложено восемь пробных площадей размером 100×100 м с использованием полностью рандомизированного плана отбора проб вдоль основного направления ветра. Удаленность от центра города составляла 10, 15, 20 и 30 км как на север, так и на юг. Обнаружены значительные различия средней высоты древостев (p > 0,001) и диаметра на высоте 1,3 м (p > 0,001). В целом все изученные лесонасаждения относились к III, IV и V классам бонитета, т. е. характеризовались относительно плохим состоянием с точки зрения индекса участка. Более высокие индекс участка и качество семян у Larix sibirica Ledeb. наблюдались в наиболее удаленных от центра города местах, и, наоборот, самые низкие по качеству семена были найдены недалеко от центра. Это позволяет утверждать: леса, произрастающие близко к источникам загрязнения, имеют потенциальный риск деградации, а их репродуктивные органы чувствительнее к воздействию вредных веществ, чем у деревьев, расположенных в экологически более благоприятных районах. Для цитирования: Udval B., Gerelbaatar S., Dashzeveg Ts., Lobanov A.I. Seed Quality of Larix sibirica Ledeb. Depending on the Distance between Forest Areas and Pollution Sources around Ulaanbaatar City of Mongolia // Изв. вузов. Лесн. журн. 2021. № 4. С. 23–35. DOI: 10.37482/0536-1036-2021-4-23-35

Composite materials based on wood filler are promising materials that are actively conquering the market. This is due to the advantages of using these materials in various fields: weather resistance and environmental compatibility, easy machining and possibility of recycling. Furthermore, it is sustainable use of wastes of timber sawing and furniture and woodworking industries, as well as low-grade wood. Wood powder is also known to be one of the components of consumables used in additive 3D printing technologies. Over the last decade, the commercial use of 3D printers has increased rapidly due to the fact that it allows creating prototype objects of complex shape based on a computer model. Experimental studies were carried out to determine the tensile strength and rheological properties of a composite made of polylactide 4043D, untreated wood powder brand 140 and wood powder thermally modified at 200 and 240 °C. The composite is intended for creation of three-dimensional objects by extrusion using a 3D printer. It was found that with an increase in the amount of filler in the composite, the tensile strength decreases. Also, samples with thermally modified filler show an increase in tensile strength in comparison with samples with untreated filler. Prototypes of 3D threads with different composition were obtained, during the study of which the melt flow index was examined. It was found that with increasing temperature of wood filler treatment the melt flow index increases. With a lower content of wood powder in the melt composition, there is a 2-fold increase in the melt flow index. The knowing of the rheological properties of the resulting compositions will allow achieving maximum performance and reduction of energy and production costs. For citation: Sabirova G.A., Safin R.R., Galyavetdinov N.R., Shaikhutdinova A.R., Khayrullin R.Z. Studying the Rheological Properties of a Polylactide Melt Mixed with Wood Filler. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 1, pp. 173–179. DOI: 10.37482/0536-1036-2021-1-173-179 Funding: The reported study was funded by RFBR, project number 19-33-90249
Композиционные материалы на основе древесного наполнителя, являясь перспективными, активно завоевывают рынок. это связано с преимуществами применения данных материалов в различных областях: стойкость к атмосферным воздействиям и экологичность, легкость механической обработки и возможность утилизации отходов. Кроме того, это и рациональное использование низкосортной древесины, а также отходов лесопиления, мебельной и деревообрабатывающей промышленности. Известно применение древесной муки в качестве одного из компонентов в аддитивных технологиях 3D-печати. За последнее десятилетие коммерческое использование 3D-принтеров возросло благодаря тому, что они позволяют создавать объекты-прототипы сложной формы на основе компьютерной модели. Проведены экспериментальные исследования по определению предела прочности на разрыв и реологических свойств композита из полилактида 4043D и термически обработанной при температуре 200 и 240 °С и необработанной древесной муки марки 140, предназначенного для создания трехмерных объектов методом экструзии с помощью 3D-принтера. Установлено, что с увеличением количества наполнителя в композите уменьшается предел прочности при растяжении, а также что по сравнению с образцами из необработанного наполнителя у образцов из термически модифицированного наполнителя наблюдается возрастание предела прочности. Получены опытные образцы различных по составу 3D-нитей, для которых был исследован показатель текучести расплава. Показано, что с ростом температуры обработки древесного наполнителя этот показатель повышается. При меньшем содержании древесной муки в составе расплава отмечается его увеличение в 2 раза. Знание реологических свойств получаемых композиций позволит достигнуть максимальной производительности, снизить энергозатраты и себестоимость готовой продукции. Для цитирования: Sabirova G.A., Safin R.R., Galyavetdinov N.R., Shaikhutdinova A.R., Khayrullin R.Z. Studying the Rheological Properties of a Polylactide Melt Mixed with Wood Filler // Изв. вузов. Лесн. журн. 2021. № 1. С. 173–179. DOI: 10.37482/0536-1036-2021-1-173-179 Финансирование: Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 19-33-90249.

The accuracy of the thickness of lumber is one of the most important indicators of sawing. It is inextricably linked with saw stabilization in the plane of the greatest stiffness. The aim of the study is to eliminate the influence of lateral force on the saw blade and the thickness of the resulting lumber. The issue of eliminating the influence of lateral force in frame sawing and sawing on band saws belongs to the constructive decision in combination with the analytical one according to classical methods. Therefore, the most important issue in the development of a new machine is to identify the presence of a huge range of frequencies of natural and parametric oscillations of saw blades. Previously, these frequencies could not be analytically found to the full extent and, respectively, the tuning out the machine operating frequencies of the possible oscillation frequencies of saw blades could not be carried out. Due to the complexity and the science intensity of the problem solving, it is not conceivable without modern numerical methods of calculation. Among them are the finite element method, modern software of NX and ANSYS, as well as other original programs. One of such methods, which allow to reduce the influence of lateral force, is determination of stability of the plane form of bending by the Eulerʼs method. The technical solution presented by a fundamentally new saw block with a circular translational motion of the blades reduce dramatically the impact of lateral force on the accuracy of sawing in conjunction with a number of other advantages. At the same time, the issue of ensuring the dynamic stability of the blades both when sawing and at idling speed is solved. It is necessary to point out that with circular translational motion the tooth side cutting edges are under alternating load when scraping over the cut surface. Therefore, the tooth cutting element is a subject of increased strength requirements. The angles of their sharpening were adjusted in order to preserve the integrity of the corners of the teeth tips. The possibility of strengthening the teeth lateral cutting edges of saw blades made of steels of different grades was investigated. The reasons of wear and corrosion, both the elements of the saw module and its operating part (blade teeth) were studied and it was decided to supply the teeth with a hard alloy of the stellite type as the most optimal. However, this provision requires additional targeted field tests. Preliminary calculations showed that the daily productivity of a machine with circular translational motion of the blades (model M2005) in comparison with saw frames increases by 2–4 times; in comparison with band saw equipment of any class by 3–6 times; and in comparison with the circular saw equipment (for small and medium enterprises) by 2–4 times. Analyzing the design scheme and the dynamics of the saw modules, it is possible to find a number of advantages of the multi-saw unit presented as part of the machine. The simplicity and reliability of the design allows us to hope for high functional characteristics. Among those we should highlight the following: increasing the accuracy of sawn products due to the rigidity of short blades, increasing the productivity, improving the quality of treated surfaces, as well as reducing the energy consumption, relatively light weight and dynamic balance of the main units with increased mobility of equipment and the absence of a massive foundation. For citation: Blokhin М.A., Podlesny D.A., Rodionov O.A. Solving the Problem of Reducing the Influence of Lateral Force on the Saw Blade Stability. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 2, pp. 118–128. DOI: 10.37482/0536-1036-2020-2-118-128
точность толщины пиломатериалов является одним из самых важных показателей пиления. она неразрывно связана с обеспечением устойчивости пилы в плоскости ее наибольшей жесткости. Цель исследования – устранение влияния боковой силы на пильное полотно и разнотолщинность получаемого пиломатериала. Классическими методами, при рамном пилении и пилении на ленточнопильных станках, задача устранения влияния боковой силы относится к конструктивному решению в совокупности с аналитическим. Поэтому важно при разработке нового станка выявить наличие огромного спектра частот собственных и параметрических колебаний пильных полотен. Ранее эти частоты не могли быть найдены аналитически в полном объеме и, соответственно, не могла быть осуществлена отстройка рабочих частот станка от возможных частот колебаний пильных полотен. в силу сложности и наукоемкости решение этой проблемы невозможно без применения современных численных методов расчета. К ним относятся: метод конечных элементов, программные продукты NX и ANSYS и другие оригинальные программы. одним из методов, который позволяет снизить влияние боковой силы, является определение «устойчивости плоской формы изгиба по л. Эйлеру». техническое решение, представленное принципиально новым пильным блоком с круговым поступательным движением полотен, значительно снижает влияние боковой силы на точность пиления в совокупности с рядом иных достоинств. одновременно с этим решается задача обеспечения динамической устойчивости полотен как при пилении, так и в режиме холостого хода. необходимо отметить, что при круговом поступательном движении боковые режущие кромки зубьев испытывают знакопеременную нагрузку, скобля по поверхности пропила. Поэтому к прочностным характеристикам режущего элемента зуба предъявляются повышенные требования. Для сохранения целостности уголков кончиков зубьев были скорректированы углы их заострения. Проведено исследование возможности упрочнения боковых режущих кромок зубьев пильных полотен, изготовленных из сталей различных марок. в ходе изучения причин износа и коррозии элементов пильного модуля и его рабочей части (зубьев полотна) принято решение о снабжении зубьев твердым сплавом типа «стеллит». однако это требует проведения дополнительных натурных испытаний. Предварительные расчеты показали, что суточная производительность станка с круговым поступательным движением полотен (модель М2005) по сравнению с лесопильными рамами увеличивается в 2–4 раза, с ленточнопильным оборудованием любого класса – в 3–6 раз, с круглопильным оборудованием (для малых и средних предприятий) – в 2–4 раза. Анализ конструктивной схемы многопильного блока и динамики движения пильных модулей выявил ряд достоинств. Простота и надежность конструкции позволяет надеяться на высокие функциональные характеристики, среди которых следует особо отметить рост производительности оборудования, повышение точности пилопродукции за счет жесткости коротких полотен, улучшение качества обработанных поверхностей пиломатериалов, снижение энергопотребления, относительно малый вес, динамическую сбалансированность основных узлов при повышенной мобильности оборудования и отсутствии массивного фундамента. Для цитирования: Blokhin М.A., Podlesny D.A., Rodionov O.A. Solving the Problem of Reducing the Influence of Lateral Force on the Saw Blade Stability // Изв. вузов. Лесн. журн. 2020. № 2. с.118–128. DOI: 10.37482/0536-1036-2020-2-118-128.

A study of the scale effect on the reservoir permeability and porosity over a wide range of the void structure appears to be a significant research task. In this work, we aimed to investigate the scale effect over a wide range of alternating reservoir properties, depending on changes in the void structure, as well as to assess the feasibility of using a whole core with a retained drilling diameter in determining the permeability and porosity of complex reservoirs. For the first time, core samples are proposed to be selected on the basis of space zoning, which takes into consideration the void structure and the scale effect. Filtration studies using such samples are expected to correctly reflect the physical and hydrodynamic characteristics of the reservoir, thus being valuable for calculating reserves and designing project documentation. Based on the performed linear discriminant analysis, the practical problem of dividing the D3fm object of the Tedinskoye oil field by the type of productive sediment reservoir is solved. In addition, an analysis of the results of physical and hydrodynamic studies confirmed the significance of the scale effect when studying the porosity and permeability properties of complex reservoirs. A significant effect of the void structure on the value of residual water-oil saturation is demonstrated. The feasibility of using whole core samples is substantiated, taking into account the quantitative measure of the scale effect differentiated over a wide range of porosity and permeability when determining the boundary values of porosity for carbonate deposits of the D3fm object of the Tedinskoye oil field. The obtained results show that the calculation of geological and recoverable reserves should take into account both the scale effect and the structural features of the void.

The article provides information on the outcrops of the Neogene-Quaternary riverine sediments of the North-Western Black Sea coastal area. A description of five outcrops of fluvial deposits located on the territory of the modern basins of the Dniester and Prut rivers is given. Based on the granulometric composition of the sediments and the presence in them of the fossil shells of freshwater bivalve mollusks (Bivalvia: Unionoida), an assumption has been made about the characteristics of the ancient river ecosystems of the Dniester and Prut on different Pliocene and Pleistocene time sections. A review of the data in the body of literature on the geological age of the studied outcrops was undertaken. The localities considered provide information on the sedimentation conditions in this region from the Pliocene to the Late Pleistocene. Previously, various approaches were used for dating such rocks and for determining the stratigraphic position of fossil material found in them. The article considers the method of amino acids racemization as one of the approaches. Racemization allows to obtain new data on the stratigraphy of Neogene-Quaternary riverine sediments and to solve the problem of their dating. The sampling principles of carbonate material for the analysis of amino acids from the mollusk shells and features of sample preparation are described. Five amino acids were used: aspartic acid (Asp), glutamic acid (Glu), leucine (Leu), phenylalanine (Phe) and isoleucine (Ile). The D/L ratios were analyzed (amino acid racemization (or AAR) is the interconversion of amino acids from one chiral form (the L – (laevo) amino acids which are the building blocks of proteins) to a mixture of L- and D- (dextro) forms. The extent of racemization is measured by the ratio of D/L isomers (it increases as a function of time and temperature and can be used for geochronology) from the same group of fossils (genera), which were preserved under similar environmental conditions, inorganic geochemistry and thermal histories. Based on the obtained values, it can be concluded that the analysis of the racemization of amino acids is useful for determining the geological age of fossil shells of freshwater bivalve mollusks, but there are limitations regarding age. In the shells of the Pliocene sites, the values of some amino acids are close to one, indicating that the racemization took place. D/L values in shells from Pleistocene localities allowed the determination of their stratigraphic position.

Phytoplankton constitutes a key part of all aquatic ecosystems. It produces organic matter, thus forming the first level of food chains in water bodies. In addition, phytoplankton plays a major role in the water quality formation. The studies of algocoenosis always remain relevant, since the obtained data provides important information on the ecological status of water bodies. This information can subsequently be used for planning and implementing environmental measures, which are particularly significant for water bodies located in specially protected areas. National parks existing for the purposes of nature preservation, education and research are also designed for tourism, which makes their ecosystems more vulnerable. Population residing in such territories and its economic activity may also carry some environmental risks, which necessitates regular complex observations. This paper covers the state of spring phytoplankton community of Lake Kenozero in 2018, its qualitative and quantitative characteristics (species composition, abundance and biomass). In the course of research, we identified 70 phytoplankton taxa belonging to seven divisions: Bacillariophyta, Dinophyta, Chlorophyta, Cyanophyta, Chrysophyta, Xanthophyta and Euglenophyta. The dominant species complex included diatoms (Asterionella formosa, Melosira granulata, Tabellaria fenestrata), representatives of Dinophyta (Gymnodinium sp.), as well as small euglenoids. Species diversity was estimated using the Shannon-Weaver index. Aquatic environment contamination was assessed, i.e. the saprobity index was calculated and the class of surface water quality was determined. According to the water quality classification of water bodies and watercourses by hydrobiological indicators, Lake Kenozero was assigned the second class of water quality (moderately polluted).

Phytoplankton constitutes a key part of all aquatic ecosystems. It produces organic matter, thus forming the first level of food chains in water bodies. In addition, phytoplankton plays a major role in the water quality formation. The studies of algocoenosis always remain relevant, since the obtained data provides important information on the ecological status of water bodies. This information can subsequently be used for planning and implementing environmental measures, which are particularly significant for water bodies located in specially protected areas. National parks existing for the purposes of nature preservation, education and research are also designed for tourism, which makes their ecosystems more vulnerable. Population residing in such territories and its economic activity may also carry some environmental risks, which necessitates regular complex observations. This paper covers the state of spring phytoplankton community of Lake Kenozero in 2018, its qualitative and quantitative characteristics (species composition, abundance and biomass). In the course of research, we identified 70 phytoplankton taxa belonging to seven divisions: Bacillariophyta, Dinophyta, Chlorophyta, Cyanophyta, Chrysophyta, Xanthophyta and Euglenophyta. The dominant species complex included diatoms (Asterionella formosa, Melosira granulata, Tabellaria fenestrata), representatives of Dinophyta (Gymnodinium sp.), as well as small euglenoids. Species diversity was estimated using the Shannon-Weaver index. Aquatic environment contamination was assessed, i.e. the saprobity index was calculated and the class of surface water quality was determined. According to the water quality classification of water bodies and watercourses by hydrobiological indicators, Lake Kenozero was assigned the second class of water quality (moderately polluted). Citation: Otchenash NG, Dvoryankin GA, Imant EN (2019) State of spring phytoplankton and quality of the Kenozero waters in 2018. Arctic Environmental Research 19(1): 43–48. https://doi.org/10.3897/issn2541-8416.2019.19.1.43

The objective of the research is to identify the main patterns of spatial distribution of natural and anthropogenic radionuclides (RN) in Naryan-Mar. Urban soils are formed by means of natural soil transformation with the participation of technogenic sedimentogenesis, which leads to disturbance of natural RN migration processes and contributes to the complex structure of natural and anthropogenic RNs contamination of tundra soils. The specific activity of anthropogenic (134Cs, 137Cs) and natural (226Ra, 232Th, 40K) RNs in Naryan-Mar soil was determined. The local low-intensity anomalies (LLIA) of anthropogenic RNs result from transboundary transfer; 134Cs and 137Cs are concentrated in soils with a well-shaped vegetable layer. 226Ra and 232Th LLIAs are confined to regions with stone buildings. 40K LLIAs are conditioned by high density of grassland vegetation involving 40K in the biological cycle. The statistical manipulation of the acquired data involved correlation and factor analysis techniques. The statistical analysis demonstrated a moderate and salient correlation between the content of 232Th and 40K in the soils of the areas built up with wooden houses and the soils of the recreation area, respectively. There is a salient correlation between the content of 134Cs and 40K as well as between 134Cs and 232Th in the soils of the recreation area. The area occupied by technological buildings demonstrates salient and high negative correlations between the content of 226Ra and radionuclides of 40K and 234Th. The multidirectional nature of the 226Ra and 232Th accumulation processes can be explained by their different mobility in the environment. A factor analysis of the specific activities of the radionuclides in the soils (based on the varimax method) revealed that the strongest factor (28%) conjointly regulates the 134Cs and 40K content, which testifies to their affiliation to non-mobile cationogenic elements. The second factor (25%) identified through an analysis of the overall data array may signify that organic matter plays a major role in the 137Cs retention.

For a long time one of the main ways of teaching vocabulary in ESP used to be learning the lists of specialized words and reading and translating the texts. Nowadays, with the appearance and a wide spread of modern technologies and the necessity to encourage autonomy, they need to be revised.

The modernization and industrialization in the USSR have very specific features due to the specific features of the totalitarian Soviet system itself.