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The research purpose is to analyse the self-regulation of students who use the massive open online course (MOOC) technology to learn the exact sciences. The sample included 252 students: females were 47%, and males were 53%. The average age of students was 20.08 ± 0.72. The students were divided into two groups: group 1 consisted of students who learnt the Digital singular (nano) optics course online using the MicrosoftTeams platform with teacher's support; group 2 consisted of students who learnt the MOOC course individually. The relationships between self-regulation and academic success were also analysed. The research found that the overall level of self-regulation of students using MOOCs was 40% higher. In students who learnt online using the MicrosoftTeams, the level of self-regulation was average and amounted to 24.96 ± 1.32. In students who learnt the course based on the MOOC technology, the level of self-regulation was high and amounted to 35.02 ± 1.44 (p < 0.05). The research of self-regulation shows higher results among the students who learnt using MOOCs platforms: flexibility -- 46%, planning -- 23% and results assessment -- 15%; modelling and programming were no different. The average success score of students after learning the course on the MicrosoftTeams platform was 3.83 ± 0.36, and in the MOOC group, it was 4.43 ± 1.89.

Over the course of the last decades, closed-loop supply chains (CLSC) and reverse logistics issues have attracted increasing attention owing to strict environmental laws, social responsibilities, economic interests, and customer awareness. Hence, the issue of closed-loop supply chain and reverse logistics has emerged as a field of research in the new era. This issue has received much attention because it allows recyclable products to return to their original cycle. Therefore, this study primarily intends to present a mathematical model for designing a supply chain network for recycled products. The multi-stage and multi-period objective function of the closed-loop supply chain is presented to meet that aim. In this chain, dismantling, recycling, and disposal centers are considered. The objective function is to reduce the total cost of the closed-loop supply chain. The results of optimizing the mathematical model demonstrate that this model has the necessary efficiency for use in recycled products.

Recently, due to the increasing awareness of communities regarding environmental issues and environmental regulations, companies have evolved to provide products with lower prices and better quality to retain and attract customers. Economics should also pay attention to environmental goals. Therefore, it is essential to provide a supply chain model that can consider both economic and environmental objectives. In this paper, the green direct supply chain network is presented to an automotive company, including five suppliers, primary warehouses, manufacturing plants, distributors, and sales centers. The objectives of this model are to minimize the total cost of construction, transportation, and the amount of carbon dioxide emissions during forwarding network transportation at all levels. The proposed model is also drawn using the weight method, which is one of the methods for solving multi-objective problems, and the solution of the model part. Ultimately, it has been discussed how much the automobile company should focus on reducing carbon dioxide so that managers can determine the best solutions from the Pareto border according to their organization’s priorities, which can be environmental or financial.

We briefly outline the history of the General Catalogue of Variable Stars (GCVS) and the New Catalogue of Suspected Variable Stars (NSV catalogue). Recently, we have completed a revision of the NSV catalogue. Positional information was checked for all its stars and, in many cases, new photometric data were added. As a result, one third of all NSV stars have been transferred to the GCVS. Having determined equatorial coordinates for variable stars in globular star clusters, we began to add them to the GCVS. Two Name-lists published so far contain more than 1700 variable stars in 36 globular clusters; an additional Name-list (about 900 variable stars in 27 globular clusters) will be published before the end of 2021. We discuss problem cases in the literature and in the Catalogue of Variable Stars in Galactic Globular Clusters revealed during our preparation of the Name-lists. The future of traditional catalogues of variable stars (GCVS; AAVSO Variable-star Data Index VSX) is discussed.

Inferior alveolar nerve block (IANB) is one of the most common procedures in operative dentistry, and a deep understanding of the normal anatomical variation of the pterygomandibular space (PM) is essential for its safe and successful administration. This cadaveric anatomical study aimed to use A-silicone injections to evaluate the volume of the PM. This study was conducted using 46 human cadaver heads (25 males and 21 females). A craniometric analysis was performed using the cadavers' ages, the number of silicone cartridges (carpules) used to fill the pterygomandibular space, Izard's Facial Index (FI), and the Cranial Index (CI). A Halstead mandibular block was performed by injecting 1.7 mL A-silicone cartridges (as an equivalent to standard local aesthetic carpules volume) into the PM. The cured silicone was extracted from the dissected mandibles. The volume (length, width, and thickness) of the extracted silicone and the number of silicone cartridges used to fill the space were evaluated. The results showed that there are statistically significant positive correlations between the CI and the width of the right PM, as well as the width and length of the left PM. A statistically significant correlation was found between the width of the left PM and the age of the cadaveric heads; the higher the age, the thicker the space on both sides. The volume of the PM corresponded to 1.5 cartridges on average. [ABSTRACT FROM AUTHOR]

Relevance. The development of digital technology has given a strong impetus to the development of consumer goods sharing and the emergence of numerous online platforms that provide goods for temporary use. Research objective. This paper aims to establishing user preferences and identifying consumer trends in the sharing market in Russia, in the USA and in the UK. The study also examines the scientific literature regarding the development of the market for sharing things. Data and methods. The material for the study were the statistical data of the Google Trends service on search queries originating from the territory of Russia, the USA and the UK over the past 10 years and data on the date of creation and visiting the most popular online platforms for sharing things in these countries. Analysis of their variance was used to study the relationship between the indicators. Results. Consumer interest in sharing things in Russia, the US and the UK is increasing. There are similar trends in the market for rented items in all three countries, in particular a rapid increase in the popularity of tool and equipment rentals. The popularity of demand for rented goods in all selected countries has a pronounced annual seasonality. The leaders in the Russian sharing economy are young companies, in contrast to the USA and the UK. Website traffic of Russian sites on sharing things is low, and it lags far behind that of retailers and is much lower than in the US and the UK. In all three countries there are not only rentals according to the classic scheme, but other formats: services, the business model of which is based on the P2P principle, rent of things provided by large trading and manufacturing companies, the Try & Buy format, through which consumers can try products before buying them. Conclusions. Consumers in Russia, in the US, and in the UK are gradually moving away from owning things towards using them. The rent of things markets in Russia, the US and the UK show similar trends. At the same time, in the US and the UK, the sharing economy is more developed than in Russia, especially rent of things under the classic scheme. In all three countries, new formats for rent of things are developing.

Factors of digitalisation process influencing on stability of the enterprises in sphere of the commodity circulation are considered in the paper. In addition to a significant positive impact in the form of new opportunities for all subjects whose activities are associated with the sphere of commodity circulation, there are many threats that can adversely affect the deformation of market space through the development of digital monopolization.

The use of car sharing instead of owning a car minimises the negative impact of logistics activities on the urban environment. This research aims to show that sustainable development of densely populated cities is accompanied by an increase in Internet users’ interest in sharing services. The research of Internet users’ interest in car sharing services was based on Google Trends data on search queries originating from Russia, the United States and Canada over the past five years. In the course of this work, the hypothesis was confirmed that high user interest in car sharing is mainly observed in urban agglomerations with high population numbers and density, where the positive effects of car sharing are most noticeable. The paper emphasises the need to encourage the creation of new services in urban logistics, which will contribute to sustainable development and increase the competitiveness of cities. It also confirms the hypothesis that the growing interest of Internet users in the new service is accompanied by an increase in the market volume. User interest in established car sharing markets is at a stable level, except for the occurrence of significant events (e.g., the emergence of a new major player in the market) that stimulate an increase in interest.

Sustainable development values and concepts of responsible consumption, sharing, waste-free production and recycling are becoming more and more popular among organisations and consumers. Though food-sharing has not yet become as popular as car-sharing, it aims to solve important social food policy problems of decreasing food waste and redistributing food to support those in need. Basing on research literature, and publications in business media the paper presents the results of content analysis of materials from food-sharing platforms and websites in Russia. Authors compare foreign best practices, identify the main food-sharing models: exchange with monetary compensation, gratuitous transfer (charity), and food-sharing within the neighbouring community Problems and unresolved food-sharing issues are explained, such as lack of information about available options of food-sharing, low trust of consumers to the quality of food being shared and perception of using charitable food stock as something shameful. The paper maps possible directions for the development of food-sharing considering the existing international experience.

The growth of technologies concerned with the high demand in lithium (Li) sources dictates the need for technological solutions garnering Li supplies to preserve the sustainability of the processes. The aim of this study was to use a machine learning-based search for phosphoryl-containing podandic ligands, potentially selective for lithium extraction from brine. Based on the experimental data available on the stability constant values of phosphoryl-containing organic ligands with Li + and Na + cations at 4:1 THF:CHCl 3 , candidate di-podandic ligands were proposed, for which the stability constant values (logK) with Li + and Na + as well as the corresponding selectivity values were evaluated using machine learning methods (ML). The modelling showed a reasonable predictive performance with the following statistical parameters: the determination coefficient R 2 = 0.75, 0.87 and 0.83 and root-mean-square error RMSE = 0.485, 0.449 and 0.32 were obtained for the prediction of the stability constant values with Li + and Na + cations and Li + /Na + selectivity values, respectively. This ML-based analysis was complemented by the preliminary estimation of the host–guest complementarity of metal–ligand 1:1 complexes using the HostDesigner software. [ABSTRACT FROM AUTHOR]