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consequences. Different measures are used to combat different types of unemployment.

According to the generally accepted classification, there are three main types of unemployment: frictional, structural, cyclical.

Frictional unemployment is caused by natural origin reasons: the change of residence, search for more profitable contract terms, graduation from university, dismissal from the army, change of occupation, family reasons, etc. Structural unemployment is caused by market changes in the structure of labor demand or improvement of the production technology. Both frictional and structural unemployment are an inevitable and natural phenomenon even in highly developed economies. The combination of frictional and structural unemployment forms the natural unemployment rate. The natural unemployment rate changes over time. So, in the early 60s, it was 4% of the workforce, and now it is around 6%. Cyclical unemployment is caused by the general recession of the economic cycle, when production becomes lower, and there is an imbalance in the labor market (a reduction in total demand for labor with an oversupply of labor). This is the most serious type of forced unemployment.

In economically developed countries, the basis of unemployment is its frictional and structural types. As for Russia, the main problem is cyclical unemployment with structural elements. In modern international practice of labor market regulation, the following models are distinguished: European (Sweden, Germany, Austria); Anglo-Saxon (USA, Great Britain, Australia); Chinese; Japanese.

The European model of the labor market is characterized by a high level of legal and social protection of the employee, strict labor law standards aimed at preserving jobs, sectoral tariff regulations, a relatively small minimum wage and its small differentiation, the leading role of the state in the labor market. Citizens are socially reliably protected. European governments spend from 40 to 60% of their budgets for these purposes. Unemployed people with work experience from six months to three years receive, on average, 70% of their salary at the last place of work as benefits for the first 14 months, then – 5060%. The state policy of Western European countries has led to the fact that the unemployment rate has decreased to the level of 3-5%.

The Anglo-Saxon model of the labor market is mainly aimed at collectivecontractual regulation at the enterprise and firm level, and not at the region or industry. In this model, it is assumed that the employer is free to dismiss and hire employees, and there is also a great similarity of labor law with civil law. The model is characterized by high labor mobility, increased differentiation of wages, while there is a restriction by the legislative acts to provide 85% of minimum wage. This model of labor relations contributes to a more dynamic

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creation of new jobs, a decrease in the unemployment rate, and high rates of economic growth. However, when using this model, a fairly large category of citizens, whose labor income is often lower than social benefits, arises.

The Chinese model of the labor market combines state regulation of labor relations of a socialist type, in which formal similarities with the European model in the public sector are manifested. The model contains laws on labor protection, improving working conditions, minimum wages, standardized working hours, employee social insurance and labor conflicts. At the same time, the existing lag in wage growth from production growth is one of the main sources of economic growth.

The Japanese model of the labor market is a bright representative of the "lifetime employment" system. It provides guarantees for the entire period of labor activity of the employees, up to the age limit of the employee. The system of lifelong employment involves an increase in the amount of material benefits in the form of wages, bonuses, social benefits. Japan is characterized by an internal labor market focused on the intra-company movement of workers. Training of the personnel, their formation, prevention of the staff turnover, profeesional development of employees' is creative attitude to work. This feature of the Japanese labor model makes it possible for entrepreneurs in crisis and production decline not to dismiss working personnel, but to reduce working hours or transfer employees to subsidiaries.

Thus, the effectiveness of the labor market is determined by the methods and instruments of its regulation, while the choice of these methods is determined by the structure and state of the national economy.

The model of labor market regulation in the Russian Federation, which has developed over the past two decades, has adapted the labor market to changes in the economic situation with the help of labor cost. This approach ensures a high and stable level of employment and a low unemployment rate with significant differences in wages. With the help of such labor market institutions as labor legislation, the minimum wage, the employment service policy based on low coverage and the amount of unemployment benefits, the mechanism for the formation of wages maintains relative stability of employment and unemployment rates. However, the result of such a model is the deformation of employment, which is a decrease of employed in the main segment of the economy and an increase of employment outside it. The traditional schemes of fighting against unemployment in Russia are a short working day, sending employees on unpaid leave, low wages, and a flexible system of bonuses. The Russian model also provides big range of measures to support employment: unemployment benefits (the amount of these benefits is significantly lower than those in many developed countries); benefits to

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businesses for the employment of the unemployed, interest-free loans to support employment, regional benefits, etc.

In conclusion, it should be noted that in all the countries mentioned above, the unemployment rate is close to the natural unemployment rate. The best results are in the Japanese model. Comparative analysis shows that in foreign models where the labor market has been established long time ago, the government primarily provides active employment policy, its purpose to prevent unemployment, reduce its duration, promote structural transformations, and ensure the effective use of the employed. Also social support measures for the unemployed have been used.

Unlike foreign models, the Russian model uses mainly a passive policy aimed at social protection of the population. These are assistance in finding employment through labor exchanges, programs to create new jobs in the public and private sector, a system of retraining and training programs for the unemployed, targeted employment programs for youth, women, long-term unemployed, disabled people; support for small and medium-sized businesses, self-employment through the provision of preferential loans, stimulating territorial mobility of labor; organization of public works, social support for the unemployed. Given the persistence of unfavorable employment trends in Russia, it is necessary to work within the framework of an active employment policy, but in modern economic and political conditions, Russia can only support the economy by regulating the employment market within the framework of a passive policy. Thus, the presence of various employment models leads to different results in the field of employment and means that there is no single way to develop the labor market. The formation of a specific model depends on the choice of priorities in the national economy, determined by the peculiarities of the socio-economic development of countries and the degree of their involvement in the world economy.

References

1.The Law of the Russian Federation "On employment of the population in the Russian Federation" dated 19.04.1991 N 1032-1

2.Government measures to increase the stability of the economy and support citizens in the face of sanctions. [Electronic resource] – URL access mode: http://government.ru/sanctions_measures (Accessed on 04.10.2022)

3.Malkina, M. Y. Economic theory. Part II. Macroeconomics. – Nizhny Novgorod: Publishing House of UNN, 2009. - 257 p.

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Y. Tsapaeva, N. Shapurova

Saint-Petersburg State University of Architecture and Civil Engineering,

St.Petersburg, Russia

FROZEN SOILS AS A BASIS FOR THE CONSTRUCTION OF PANEL

HOUSES

In modern conditions of the development of society, the influence of endogenous and exogenous factors of the industrial revolution played a decisive role in the development of new regions, directly in such a physical and geographical region of the earth as the Arctic. Numerous settlements, industrial cities and emerging infrastructure support this narrative. There are more than 370 settlements in the Arctic with a total population of 10 million people. This 5% of the population produces 11% of the country's GDP and two-thirds of foreign exchange earnings. The region-forming center of the Arctic is Western Siberia and such cities as Nadym, Novy Urengoy. The formation and development of infrastructure in this region is complicated not only by climatic conditions, remoteness from food centers, but also by the presence of difficulties in building on permafrost.

The significant part of the Russian scientists are engaged in the study of the physical and mechanical properties of frozen soils and the study of cryolithozones, such as A.V. Pavlov, G.V. Ananyeva, D.S. Drozdov, D.A. Streletsky, N.I. Shiklomanov.

The analysis of data from stationary observations, the results of systematization of disparate literature data make it possible to assess trends in modern physical and mechanical properties of frozen soils.

According to the studies of the above scientists, climate warming can be traced both in most of the Arctic and in its Russian sector, including in Western Siberia in 2008. The strongest warming is typical for the winter period, while a slight trend can also be traced in the summer months. Over the past 25 years, the duration of the warm period in the tundra zone has increased by 5-6 days, in the northern taiga zone - by 15-17 days [7].

Based on the studies and the current situation, it can be argued that it is necessary to develop Western Siberia, which is impossible without studying the issue of the bearing capacity of frozen soils and their physical and mechanical properties.

The aim of the study is to form the methodological aspects of frozen soils in construction. To achieve the goal of the study, a number of tasks were set:

- to substantiate the basic physical and mechanical foundations of frozen soils; to form the methodological aspects of the science of frozen soils and the

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characteristics of the permafrost zone; to reveal the features of cryogenic processes and landforms; to highlight the main stages of permafrost monitoring and construction opportunities in permafrost areas.

It is substantiated that any soils that have a negative temperature and contain ice are frozen. Along with the typically frozen soils, i.e. containing ice, there are soils with a negative temperature, but without ice, for example, lowmoisture loose sandy, gravel and pebble, dry rocky and semi-rocky soils, as well as rocks saturated with mineralized waters. It is proposed that when studying the physical and mechanical characteristics of frozen soils, it is necessary to pay attention to the significant place of the ice soil (the volume of ice in which is at least 80%).

It has been proven that ice is frozen water, but ice is distinguished by the chemical composition of the original substance. In the atomic nucleus of each chemical element, there can be a different number of neutrons with the same number of protons and electrons. During the study, three isotopes of hydrogen were identified: protium (1H), deuterium (2H or D), tritium (3H). Based on the hydrogen isotopicity, 17 crystalline modifications of ice are considered [1]. With the cyclic action of negative and positive temperatures on the soil, three stages are distinguished in the latter: freezing, frozen state, thawing. The physical processes of freezing, the formation of ice, the process of solifluction are considered. As a result of the considered processes, negative phenomena of soil runoff, icing, and a drop in the strength characteristics of the soil occur.

The concepts of glaciology and geocryology are considered. Glaciology is the science of the physical properties of glaciers, their origin, development, geological activity and influence on the formation of the earth's surface. Geocryology (permafrost science) studies the patterns of formation and distribution of permafrost and the geological processes occurring in the frozen zone of the lithosphere [3, 6].

Permafrost processes have been studied. It is distinguished seasonal and long-term permafrost. Seasonal permafrost exists only in winter, a long-term permafrost persists all year round and for many years. Permafrost (cryogenic) processes manifest themselves most clearly and on a large scale in the cryolithzone. The cryolithzone includes frozen rocks, frosty rocks and chilled rocks. According to different studies, three layers have been distinguished in the vertical section of the cryolithozone: the upper layer is called active, the second layer is where the seasonal fluctuations in negative temperature occur, which are accompanied by mechanical stresses and cracking, the third most powerful layer, a kind of foundation of the cryolithozone. Two ways of permafrost formation have been identified: epigenetic and syngenetic. The first path is typical for uplands; as the weathering crust is removed, freezing penetrates deep into the rock mass. The second way is typical for the lowlands, where

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accumulative processes dominate, for example, the accumulation of alluvium in river valleys.

The features of cryogenic processes and relief forms are revealed. The transition of water into ice during freezing of soils significantly changes their physical state, deformability, strength, water permeability, as well as electrical, thermal and other properties. In addition, soil freezing is accompanied by the development of special permafrost processes and phenomena. Based on the analysis of scientific periodicals, the main permafrost processes are systematized: frost cracking, frost sorting of loose material, heaving and icing, frost weathering, cryogenic creep, thermokarst [4].

The tasks of monitoring of the physical and mechanical properties of frozen soils are determined. Monitoring of the physical and mechanical properties of frozen soils is currently considered as a unified system for observing the state of the geological environment in the conditions of the North; a system for assessing, controlling and predicting its changes under the influence of natural factors and technogenesis. In essence, this is permafrost-climatic monitoring, since one of its main tasks is to carry out quantitative assessments of current and expected in the 21st century. permafrost-climatic changes. In permafrost areas, monitoring should be carried out for all types of buildings and structures, including underground utilities [2].

The main methods of construction on frozen soils are substantiated. In case of building in areas with frozen soils, the correct choice of sites for construction with such soils is of particular importance so that they are not heaving, not subject to the formation of icing and failures. In addition, it is necessary to choose such space-planning and design solutions, as well as construction methods, in order to ensure the normal performance of buildings. The first method is recommended if the soil is hard frozen. Objects erected according to this method of using frozen soils must have the following types of reinforced concrete foundations: solid section or hollow; shell piles; pilespillars; prefabricated columnar; monolithic. Preservation of the frozen state of soils at the base is possible using the following methods: erecting a building on a backfill, installing thermal insulation under the floor, installing a ventilated underground, locating unheated rooms on the ground floor, laying cooling ventilation ducts under the floor of the building, cooling the soil with the help of freezing columns (thermosyphons) [5]. When erecting buildings according to a rigid structural scheme, it should be borne in mind that longitudinally and transversely located walls must be installed symmetrically with respect to the main axes. Walls must be made through the entire width or length of the object. The distance between the transverse bearing walls should not exceed 12 meters. Doorways are recommended to be placed evenly and to make them the same size. It is unacceptable to weaken the walls with niches, channels, strobes [8].

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The second method of construction on permafrost grounds is based on a design technique appropriate when the ground under the building (structure) is thawing. Thawing is considered acceptable during the preparation of the area for construction work or after their completion. In accordance with this design method, buildings must have an insensitive structure that is resistant to subsidence of the foundation during thawing of the soil.

References

1.Alekseev V.R. This mysterious ordinary ice / V.R. Alekseev // Science and technology in Yakutia. – 2020. – №2. – p. 98-106

2.Goncharov Y.M. Bases and foundations on permafrost soils / Y.M. Goncharov. - Yakutsk: Publishing House of the Institute of Permafrost Science of the Siberian Branch of the Russian Academy of Sciences, 2016. – p. 405

3.Ershov E.D. General geocryology: textbook / E.D. Ershov. –

Publishing House of Moscow university. – 2002. – 682 p.

4.Kudryavtsev V.A. General permafrost (geocryology) / V.A. Kudryavtsev. – 2nd edition. – Publishing house of Moscow State University, 1978. – 464 p.

5.Mangushev R.A., Sakharov I.I. Foundations and foundations / R.A. Mangushev, I.I. Sakharov. – Moscow: DIA Publishing House. – 2019. – 468 p.

6.Ostanin O.V. Glaciology and permafrost: tutorial / O.V. Ostanin, G.S. Dyakova, V.P. Galakhov; AltGU, geogr. fak. – Barnaul: AltGU Publishing House. – 2016.

7.Streletsky D.A., Shiklomanov N.I., Grebenets V.I. Changes in the bearing capacity of frozen soils due to climate warming in the north of Western Siberia. Cryosphere of the Earth / D.A. Streletsky, N.I. Shiklomanov, V.I. Grebenets // Earth's cryosphere. – 2012. – vol. XVI. – №1. – p. 22-32

8.The subtleties of construction on permafrost soils [Electronic resource]:

-Electron. text data. - St. Petersburg. – 2021. – Access mode: https://borey- stroy.ru/articles/principy-stroitelstva-na-vechnomerzlyh-gruntah/ (Accessed on 01.10.2022)

F.Sh. Bekmurzaeva, A.A. Efimov

Saint Petersburg State Forest Technical University named after S.M. Kirov, Saint-Petersburg, Russia

SOSNOWSKIY`S HOGWEED CONTROL PROBLEM

Introduction history of Sosnowskiy`s hogweed. Sosnowskiy`s hogweed or Heracleum sosnowskyi – plant of the Heracleum genus from the Umbelliferae

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family with height up to 3-5 meters, with large inflorescences and leaf rosettes composed of 2-3m leaves, each inflorescence contains from 30 to 150 flowers, so one specimen can contain about 80000 flowers.

Sosnowskiy`s hogweed natural habits are located in meadows and forests of south-eastern regions of Asia, primarily the Caucasus, the Transcaucasia and northeastern Turkey. In 1944 Sonsowskiy`s hogweed was firstly described by plant finder Ida P. Mandenova and named in honor of Caucasian flora researcher

– Dymitr Sosnowsky.

First Sosnowskiy`s hogweed species beyond their native habits were sprout out of seeds from Kabardino-Balkaria and introduced in northwest of Russia as an experimental fodder crop in 1946. Starting from the 1960s Sosnowskiy`s hogweed was being cultivated in industrial scale all over the Russia and former Soviet Union Countries such as Belarus, Ukraine, Hungary, Poland, Lithuania, Latvia, Estonia, and the former German Democratic Republic [1].

Further observations made promoting of this hogweed as nutrious, healthy silage plant not feasible due its hazardous toxicity, which may cause severe skin burns among animals, negative impact on diary production by making milk from cattle that had been eating hogweed, tasteless [2]. Cultivation of this species had been finally terminated by 1980s. After that moment gradual collapse of socialism led to the decline of agricultural branch, dereliction of collective farms and decrease of liquidation intensity of Sosnowskiy`s hogweed [3].

Chemical hazard and impact on ecology. During examination of Sosnowskiy's Hogweed chemical composition allopathic and allergic compounds have been explored. These are mostly: coumarins, furanocoumarins, hydrocarbons, alcohol, esters, aldehydes etc. [3]. Depending on part of plant is being examined classes of chemical compounds vary. For instance, plant fruits contain derivatives of coumarins – phototoxic furanocoumarins, which may increase skin photosensitivity among animals, humans and lead to reddening and accumulation of fluid in skin. The damaged skin area may remain sensitive for years [5]. Chemical composition of essential oils extracted from the seeds consists of 62 compounds in total. Aliphatic esters (82.9%) were the main constituents of the oil, followed by aliphatic alcohols (11%)[6]. Leaves of Sosnowskiy`s hogweed are also rich with phenol contents [7].

All these chemical elements are capable of suppressing vitality of grampositive and gram-negative bacteria, viruses, as well as being toxic to vertebrates and invertebrates [3]. Ability of Sosnowskiy`s hogweed to impact on majority of taxons emerges in disturbances of biomass proportions and biotic cycles in biogeocenosis. For instance, ground dwellers and farmland birds responded negatively to H. sosnowskyi towards open habitats, while a more negative response towards forest habitats was observed in birds associated with

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bushes [8]. Presence of this hogweed influences on quantity of fungi in soil. The share of yeast-like Trichosporon fungi with high hydrolytic activity was higher in the soil under H. sosnowskyi [9]. In opposite, Under H. sosnowskyi were less ascomycetes Candida vartiovaarae, Wickerhamomyces anomalus [10].

Dispersal and methods of fight. Sosnowskiy`s hogweed control problem is hidden in mechanisms of its widespread distribution. The seeds of S. Hogweed obtain high possibility of germination regardless of temperature regime – from 71 to 94%. The average density of H. sosnowskyi seeds, expressed per m2 and pooled across localities, was 9025 ± 2229 (mean ± SD) in autumn, 14,881 ±7217 in spring and 4013 ± 1216 in summer for total seeds, and 5400 ±3281, 9045 ± 6411 and 1119 ± 889, respectively, for living seeds [11]. Having been melliferous plant, seeds of this plant are spread by plenty of insects: 69 species that visited Heracleum sosnowskyi inflorescences were identified in Moscow oblast [12]. Seeds may be spread by animals, humans by attaching to the clothes or fur. Local and long-distance dispersal can be also implemented by river flows and wind respectively. Taking into account fact that Sosnowskiy`s Hogweed does not require special environment conditions, being able to grow in both anthropogenic (roadsides, disturbed areas, agricultural fields, abandoned farmyards, gardens) and natural habitats (bushes, grasslands, parks, pastures, abandoned orchards) [13], this plant represents great menace to ecosystems due its alarming reproduction estimates and flexibility of occupying different land types.

Although current fighting methods against Sosnowskiy`s hogweed don’t make its eradication feasible some of them may prevent further invasion. These methods can be divided into 3 groups: mechanical (mowing, root cutting), chemical (using herbicides, inhibitors) and biogical (grazing, pests spread). Mechanical methods as mowing and cutting might be relatively efficient in cases when density of specimen is low, but considered unsafe (risk of gaining skin, respiratory system lesion by contacting stalk poisons or inhaling them in evaporated form) and labour-instensive. Application of herbicides is probably the most efficient method from those available, but puts in danger vitality of other vegetation, forage crops as well as intentional spread of pests like weevil Nastus faustii [14]. Treatment with inhibitors like gibberellin (GA3) may significantly decrease seed-bank of Sosnowskiy`s hogweed. It was observed that even low GA3 concentration (0.07 mM) significantly changed the percentage of seeds from 98.0% to 47.6%. However, simultaneous application of inhibitors may even increase the seed germination, so it requires systematic highlycoordinated approach [15]. Of a special interests are selective herbicides. Despite lack of research they have already shown encouraging results in fight with Sosnowskiy`s hogweed within coniferous forests. Suppression rate of this plant by herbicides like Anchor-85, Mortar, Magnum equals 89–97% [15].

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Sosnowskiy's Hogweed has become a serious threat to the environment after decline of USSR agricultural system and intensity of eradicating this specimen. For the current moment countries of the former Soviet Union are vulnerable to Sosnowskiy's Hogweed widespread distribution due to lack of sufficiently effective methods of treatment. However, implementation of already available methods can prevent further infestation. Further research and development in direction of inhibitors and selective herbicides may be the key to solving Sosnowskiy's Hogweed control problem, but it requires high coordination, level of responsibility between countries, because only a systematic and long-term approach makes future liquidation of this specimen feasible.

References

1.Moravcová, L.; Gudžinskas, Z.; Pyšek, P.; Pergl, J.; Perglova, I. Seed Ecology of Heracleum mantegazzianum and H. sosnowskyi, Two Invasive Species with Different Distributions in Europe // Ecology and Management of Giant Hogweed (Heracleum mantegazzianum): CAB International: Wallingford, UK, 2007; P. 157–169.

2.Sosnowsky’s hogweed – current environmental problem. [Electronic resource] URL access mode: https://sciendo.com/pdf/10.1515/oszn-2017-0020 (Accessed on 11.10.2022)

3.Grzedzicka, E. Invasion of the Giant Hogweed and the Sosnowsky’s Hogweed as a Multidisciplinary Problem with Unknown Future – A Review. Earth 2022, 3, 287–312. [Electronic resource] URL access mode: https://www.researchgate.net/publication/358702180_Invasion_of_the_Giant_H ogweed_and_the_Sosnowsky's_Hogweed_as_a_Multidisciplinary_Problem_wit h_Unknown_Future-A_Review. (Accessed on 13.10.2022)

4.Jahodová Š., Fröberg L., Pyšek P., Geltman D., Trybush S., Karp A. Taxonomy, identification, genetic relationships and distribution of large Heracleum species in Europe // Ecology and Management of Giant Hogweed (Heracleum mantegazzianum): CAB International, Wallingford, UK, P. 1–19.

5.Nielsen, C., Ravn, H.P., Nentwig, W., Wade, M. The Giant Hogweed Best Practice Manual: Guidelines for the Management and Control of an Invasive Weed in Europe // Forest and Landscape Denmark, Hoersholm, 2005. 44p. [Electronic resource] URL access mode: https://www.researchgate.net/publication/260202289_The_Giant_Hogweed_Bes t_Practice_Manual_Guidelines_for_Management_and_Control_of_an_Invasive _Weed_in_Europe. (Accessed on 11.10.2022)

6.Composition and herbicidal effect of Heracleum sosnowskyi essential

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