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The results of a numerical study of laminar fluid flow and heat transfer in an annular gap between two cylinders with a rib on one of the walls are presented. A mechanism for intensifying heat transfer between two cylinders, when one is rotating, was studied. Intensification was achieved by installing a single rib on the inner or outer cylinder. The rib was oriented along the annular system radius and occupied half the height of the gap between cylinders. The problem was formulated in two dimensions. The Reynolds number was varied in the range from 100 to 1000. Air was the working medium. Four options for the location of the intensifying rib were considered. A fundamental difference in the structure of the recirculation zone was noted for different rib locations. Maximum heat transfer was achieved on the wall of the stationary cylinder opposite the rib mounted on the rotating cylinder. Its multiple increase was observed compared to the case of rotating smooth cylinders.

This paper examines interaction of propagating waves with gas bubbles contained in liquid and the behavior of gas bubbles in a gas-liquid mixture. A description of the experimental setup for studying the influence of a propagating wave on gas bubbles is presented and the observed phenomena are described.

The article considers S.A. Karaganov’s concept of Siberization and the possibilities of using such theoretical tools as V. Christaller’s theory of central places and A. Lösch’s theory of economic landscape for its implementation. It is concluded that a version of the relativistic theory of central places for systems with a dispersed (distributed) main center may be useful for describing and planning urban settlement systems in Asian Russia, which are significantly less mature than those in the European part of the country. In the Far East, it is possible to form a system of central places with a hierarchy corresponding to <i>K</i> = 2. It has been established that settlement development in the post-industrial period should not be treated as a secondary factor in relation to production development, since the standort (location) of modern enterprises should ensure not only reduced costs for energy, raw materials and semi-finished products, as well as proximity to markets, but also advantages in the competition for highly qualified labor. Only a high-quality urban environment can provide these benefits. It is reasonable to expect different patterns of production distribution in the north and in the south of Siberia. In the north, according to Weber, the standort should ensure minimal costs, while in the south, the location according to Lösch will predominate. Such a standort ensures maximum profit. It is shown that even in the most developed regions of Siberia, the location of new high-tech production facilities “according to Weber” is still inevitable. This follows from the continuous nature of territorial development established by B.N. Zimin: each new industry develops it anew. Siberization is being hampered by a serious delay in the implementation of long-discussed railway infrastructure projects: the Barentskomur, the North-Siberian Railway, and the Northern Latitudinal Passage. Only the construction of these railways will significantly increase the cargo-generating base for the ports of the Northern Sea Route. Meanwhile, projects far less urgently needed for the country are being discussed, such as a bridge to Sakhalin and even a tunnel under the Bering Strait.

The resilience of forest ecosystems to natural and anthropogenic impacts was studied. The influence of climatic, biological, landscape, and anthropogenic factors on the productivity of forests in the Zeysky Nature Reserve was assessed. Climate trends and the sensitivity of the phytoproduction process to changes were analyzed, and a periodization of hydrothermal parameters was provided. The research methods included collecting tree cores to estimate annual increments and analyzing climate data using statistical methods. Based on the analysis of tree-ring chronologies, the relationship between climatic fluctuations and radial tree increment was retrospectively assessed. To improve the accuracy of the analysis, methods of cross-dating and standardization of tree-ring series were used. The resulting time series of tree increment were compared with the data on air temperature and precipitation provided by the nearest weather station. Correlation and regression analyses were used to assess the statistical significance of the identified relationships between climatic factors and tree increment. Specifically, the Pearson correlation coefficients were calculated between tree increment and average monthly temperature and precipitation values for different periods of the growing season. The results of the regression analysis made it possible to assess the contribution of each climatic factor to the overall variability of tree increment. It has been established that temperature conditions, especially in spring and summer, significantly affect tree increment, while precipitation plays a secondary role. At this stage of research, it was not possible to identify a clear influence of climatic factors on forest productivity in the long or short term. Despite the correlations identified, it is necessary to consider the influence of other factors, such as competition between trees, stand age, soil conditions, and the impact of pests and diseases, which may mask or enhance the influence of climatic factors.

The manifestation of the Little Ice Age in the south of the mainland of the Russian Far East is analyzed. The study is based on a synthesis of paleogeographic data, which, in the absence of historical records, are the most informative for reconstructing changes in the natural environment. The main natural archives were deposits of mountain lakes and bogs located in different landscape zones of the low- to mid-mountain areas of the Sikhote-Alin and East Manchurian Mountains (at absolute elevations from 300 to 1600 m). Based on changes in the composition of diatom flora, as well as components of forest and bog ecosystems, abrupt climatic changes that occurred from the 12^th to 13^th centuries, including the transition period from the Medieval Warm Period, were reconstructed. It has been established that the medieval cooling in the south of the Far East was humid, with increased precipitation, including winter precipitation, and frequent floods. In this context, short-term periods of decreased humidity and seasonal droughts were observed. Typically, drier conditions coincided with solar activity minima. The cooling had an impact on the development of mountain landscapes, resulting in a change in the ratio of forest-forming species, a shift in the boundaries of landscape zones, widespread development of sphagnum bogs, and the emergence of species of northern regions among peat-forming plants. At the end of the Little Ice Age, settlement and active development of the territory became the leading factor in landscape transformation.

The relevance of the study is determined by the low population size and density, as well as the shortage of labor resources in Siberia amid depopulation and migration outflow from the territories. Significant differences in the socio-economic status of Siberian subjects determine the population movement to more developed regions, exacerbating territorial disparities in the distribution of labor resources in the labor market. The novelty of the study lies in its comprehensive approach to studying the relationships between demographic processes, economic development of the territory and social changes in society. The features of territorial dynamics of the population in the labor market (in terms of size, growth, distribution of those employed in economic sectors, and unemployment rate) are analyzed, taking into account the influence of economic and demographic factors. Regional factors that determine the increase/decrease in the total population, the working-age population and those employed in the economy have been identified. Between 2011 and 2023, significant shifts occurred in the overall structure the population employed in the economy, with a reduction in the total number of this group within one percent. The greatest decrease in the number of employed people was typical for agriculture, education and healthcare. The largest increase in the number of employed people was recorded in trade, in such areas as the repair of vehicles and household goods, transport and communications, and in the extraction of minerals. The matrix of labor market indicators, the quality of life index, the ratio of median income to the cost of a set of goods and services, and the share of the population below the poverty line revealed a clear correlation between economic and socio-demographic indicators.

The article provides a review of publications on the problems of water management activities and riverbed processes under dynamic natural and anthropogenic impacts. Various approaches in this field (ecosystem, basin, and integral ones) are characterized. It is shown that the need to analyze the socio-ecological consequences of water management activities and riverbed processes is currently increasing. Particular importance is given to sociological methods in studying the issues of managing these processes. To illustrate the effectiveness of these methods, the authors present the results of an expert interview and a supporting qualitative in-depth interview with the local population, using the central regions of the Sakha Republic (Yakutia) as an example. The analysis of expert knowledge and public opinion made it possible to identify the main risks and factors of anthropogenic impact on the Lena River, which are most often encountered by specialists and ordinary residents of the region. The main socio-ecological consequences of water management activities and riverbed processes are identified. The strengths and weaknesses of the methods of riverbed process management are formulated. Expert and public opinion on the problems of water management and planning on the Lena River is summarized. It was found that when assessing social consequences, their primary manifestations (human and economic losses) are usually indicated. More complex social processes are mentioned only by some experts and do not have a consistent reproduction of opinions. In general, experts point out that coordination of methods for managing risks caused by riverbed processes should be improved in order to harmonize the activities of various agencies facing relevant problems. It is concluded that, given the weak formalization of the considered ideas and the conflicting interests of various social groups, the use of methods for studying the expert opinions of managers with a supporting public opinion survey proves to be effective.

The article considers the issues of methodological support for assessing the possibility of using archaeological sites in tourism activities. The research base of the identified topic in the global and Russian scientific fields is analyzed. The presented authors’ methodology evaluates each site according to five parameters, namely: transport accessibility, infrastructure provision, events, available excursion programs, as well as public activity. Based on the results of applying the methodology to five districts of the southwest of Rostov oblast (Azovsky, Aksaysky, Myasnikovsky, Rodionovo-Nesvetaysky and Ust-Donetsky), the archaeological sites most promising for inclusion in tourist-excursion routes were identified. The advantages of sites with high ratings in these districts are also described. Proposals for the further use of the assessed sites in tourism, including consideration of the differentiation of their ratings, are presented for discussion. Based on the conducted research, the authors suggested a tourist route with an archaeological focus through the territory of Rostov oblast, “The Solar Plexus of Eurasia”, which includes the sights of the region’s southwestern districts with the highest ratings. Such a route can become a growth point for inbound archaeological tourism in the region and, in the long term, serve as a basis for the formation of infrastructure-supported tourism development poles. For low-rated sites, measures have been proposed to increase their tourist attractiveness and potential use in tourist routes. Furthermore, the prospects for applying this methodology to other districts of Rostov oblast, as well as to other subjects of the Russian Federation, with the possibility of forming national archaeological routes, are outlined.

Precipitation is a key indicator for determining the climate of a region. However, erratic precipitation patterns are detrimental to urban infrastructure. The objective of this study is to forecast precipitation patterns using historical time series data. The study used precipitation data for a century (1922-2022) to project future precipitation trends for the semi-arid region of the Agra district of Uttar Pradesh, India. A seasonal autoregressive integrated moving average (SARIMA) model was employed for the same purpose. Through data decomposition and the augmented Dickey-Fuller test, the study confirms the model’s stationarity prerequisites, with the SARIMA (2, 1, 1) (0, 1, 1)12 configuration proving to be the most accurate for the study. The model accuracy was further validated through residual checks and performance assessment against established metrics, such as the Akaike information criterion, Bayesian information criterion and Hannan-Quinn information criterion. Forecasts were generated at 80 % and 95 % confidence intervals using both the “pm.auto_arima” function of the “pmdarima” package in the Python library and manual assessment for further adjustment and verification. According to the forecasts, 2022-2031 is a decade of reduced precipitation, with an average of 590 mm. This forecasted average is lower than the historical average of 643,96 mm and the median of 665,92 mm.

The article considers the problem of migration of herders from rural to urban areas of Mongolia in the wake of the country’s transition to a market economy in the 1990s. The consequences of these reforms were the loss of some livestock (the source of livelihood for rural residents), including due to natural disasters, and a lack of jobs. The article presents an analysis of the main indicators of the internal migration in Mongolia from 1990 to 2020 at the province and soum levels, and determines the changes in the population distribution and settlement system due to the internal migration. Over the past 30 years, the population of Mongolia has increased by 1203,2 thousand people, or 58,7 %. It was found that this population growth (averaging 2 % per year) differed greatly geographically. Thus, during this period, the population of Ulaanbaatar increased by 962,5 thousand people, or 179,4 % (an average of 6 % per year), which is directly related to the flow of internal migrants towards Ulaanbaatar. An analysis of the average annual population growth rate suggests that in two provinces and 21 soums, the population grew mechanically or by migration; the average annual growth rate above the national average was observed in 9 province centers and 19 soum centers. In the future, it is necessary to identify and analyze the factors influencing internal migration in order to reduce population concentration in Ulaanbaatar and other large cities of Mongolia and to stimulate return migration.