THE STUDY OF THE EXTRACTION DYNAMICS OF BIOLOGICALLY ACTIVE SUBSTANCES FROM THE BIDENS TRIPARTITA L. HERB AND ANTIOXIDANT ACTIVITY OF THE OBTAINED EXTRACTS

The interest to study the genus Bidens and in particular Bidens tripartita L. (bur-marigold herb) is unmitigated due to its antioxidant, anti-allergic, antimicrobial, antifungal, hepatoprotective, immunostimulating and hypotensive activity. This pharmacological activities are determined by the presence of flavonoids, polyphenolic compounds, polysaccharides, components of essential oils, polyacetylenes, etc. The aim of the research was to study the process of extracting various biologically active substances (polysaccharides, flavonoids, polyphenols) from bur-marigold herb with water-alcohol mixtures of various concentrations, to study their component composition, as well as to evaluate their effect on the oxidative effect of free radicals. Materials and methods. The object of the research was the herb of Bidens tripartita L. Raw materials were collected and procured on the territory of Kharkiv, Zhytomyr and Poltava regions of Ukraine. All used methods for the quantitative determination of biologically active substances were pharmacopeial and described in various monographs in the European Pharmacopoeia and State Pharmacopoeia of Ukraine. Results. The extracts of the bur-marigold herb were analyzed for the content of the extractable matter, flavonoids, polysaccharides and it was found that they are maximally extracted (about 80 %) in the 1st percolate with a drug/solvent ratio of 1:10 for all the extractants. It was found that with an increase of ethanol concentration in the extraction mixture, the content of polyphenols and flavonoids, is expectedly increased, as well as the value of the antioxidant activity of the corresponding extracts, but the amount of extracted polysaccharides is significantly reduced. Conclusions. With the selected evaluation criteria, it was found that 40 % ethanol is optimal from the point of view of balanced extraction of flavonoids, polysaccharides and polyphenols. A strong positive and statistically significant correlation was found between the content of polyphenols in the obtained extracts and their antioxidant activity (Pearson correlation coefficient, r=0.9998), slightly weaker for flavonoids (r=0.9886), and an inverse correlation between polysaccharides content and TEAC- value

Screening of Coulomb Impurities in Graphene

We calculate exactly the vacuum polarization charge density in the field of a subcritical Coulomb impurity, $Z|e|/r$, in graphene. Our analysis is based on the exact electron Green's function, obtained by using the operator method, and leads to results that are exact in the parameter $Z\alpha$, where $\alpha$ is the "fine structure constant" of graphene. Taking into account also electron-electron interactions in the Hartree approximation, we solve the problem self-consistently in the subcritical regime, where the impurity has an effective charge $Z_{eff}$, determined by the localized induced charge. We find that an impurity with bare charge Z=1 remains subcritical, $Z_{eff} \alpha < 1/2$, for any $\alpha$, while impurities with $Z=2,3$ and higher can become supercritical at certain values of $\alpha$.Comment: 4 pages, 2 figure

PRINCIPLES OF THE "GREEN" ECONOMY IN RUSSIA: CURRENT STATE, COMPARING WITH WORLD EXPERIENCE, CHALLENGES AND PROSPECTS

Background: The concept of sustainable development plays an essential role in the functioning of the modern world economy. An important component of this concept is the implementation and financing of "green" and socially-oriented projects. In Russia, this direction is only at the initial stage of its formation, therefore it is important to study it and find ways to accelerate its development. Objective: The purpose of the research is to analyze the current state of sustainable development projects financing in Russia, to identify its features and future prospects, as well as to find the most effective ways for its development. Methods: To accomplish this task, the article analyzes the dynamics of changes and key trends in the global and Russian sustainability financial markets. Their comparative analysis is carried out, the main similarities and differences are highlighted. Results: Attention is paid to both industry and subtypes distribution. The theoretical basis of the sustainable development market formation is also considered, its impact on the ESG agenda in Russia is assessed. In the final part, forecasts are made for the possible development of the international and Russian ESG markets. The most effective ways of evolving the sustainable development concept in Russia are identified. Particular attention is paid to the DeFi technologies introduction possibility to simplify and improve financing mechanisms and the implementation of "green" and socially-oriented projects

Models for dynamic correlated charge collection effects in thick CCDs

Dynamic charge collection effects in thick CCDs have received interest in recent years, due to the performance implications for both ground and space based precision optical astronomy. The phenomena manifest as the "brighter - fatter" effect in Point Spread Function (PSF) measurements, and nonlinearity and signal dependence in spatial autocorrelation and photon transfer measurements. In this paper we present validation results from simple, analytically based predictive models for this effect, using an e2v CCD250. The model is intended to provide estimations for predicting device performance based on design parameters

Analysis of four protocols based on tropical circulant matrices

Several key exchange protocols based on tropical circulant matrices were proposed in the last two years. In this paper, we show that protocols offered by M. Durcheva [M. I. Durcheva. TrES: Tropical Encryption Scheme Based on Double Key Exchange. In: Eur. J. Inf. Tech. Comp. Sci. 2.4 (2022), pp. 11–17], by B. Amutha and R. Perumal [B. Amutha and R. Perumal. Public key exchange protocols based on tropical lower circulant and anti-circulant matrices. In: AIMS Math. 8.7 (2023), pp. 17307–17334.], and by H. Huang, C. Li, and L. Deng [H. Huang, C. Li, and L. Deng. Public-Key Cryptography Based on Tropical Circular Matrices. In: Appl. Sci. 12.15 (2022), p. 7401] are insecure

An attack on a key exchange protocol based on max-times and min-times algebras

In this paper, we examine one of the public key exchange protocols proposed in [M. I. Durcheva. An application of different dioids in public key cryptography. In AIP Conference Proceedings, vol. 1631, pp 336-343. AIP, 2014] which uses max-times and min-times algebras. We discuss properties of powers of matrices over these algebras and introduce a fast attack on this protocol. This preprint has not undergone peer review (when applicable) or any post-submission improvements or corrections. The Version of Record of this article is published in Indian Journal of Pure and Applied Mathematics, and is available online at https://doi.org/10.1007/s13226-023-00469-0

OSCILLATOR STRATEGIES APPLICATION IN STOCK MOVEMENT PREDICTION ON THE RUSSIAN FINANCIAL MARKET: EFFICIENCY ISSUES

Background: Technical analysis is one of the most frequently used by traders instruments. However, many of its elements (in particular oscillators) may show varying efficiency depending on the particular markets characteristics. Therefore, taking into account the distinctive features of the Russian stock market, it is reasonable to examine which oscillators can be effectively applied on it. Objective: The purpose of the study is to analyze the effectiveness of technical analysis indicators for forecasting shares of the Russian stock market and to develop the most effective trading strategy combining various oscillators. Methods: In order to achieve this, the selection of stocks suitable for testing and technical analysis indicators representing various groups is carried out. The accuracy and the total number of signals act as criteria for the indicators effectiveness, while accuracy is given the main attention. The interval from mid-2020 to mid-2021 is used for testing. Results: Based on the results obtained, the indicators are divided into efficiency groups; recommendations for the application of each oscillator are given. The result of the study is the development of the most effective strategies for the usage of technical analysis indicators that have passed the test. The strengths and weaknesses of each formed strategy are highlighted. Conclusion: The novelty of the research lies in obtaining the results of comparing the different types of technical analysis indicators effectiveness in the modern conditions of the Russian stock market and in building optimal strategies for their application

THE EVALUATION OF FUNDAMENTAL METHODS EFFECTIVENESS ON THE RUSSIAN STOCK MARKET

Objective: The purpose of the study is a comparative analysis of various fundamental analysis indicators and indicators based on expected levels of return and risk usage. The aim also lies in identifying the most promising of them in the current state of the modern Russian stock market. Methods: To achieve this goal, 13 portfolios are formed and analyzed based on the application of various indicators. Both the effectiveness of individual indicators and the methods of their application are compared; index and average levels of profitability are added as an additional basis for comparison. For the purposes of the study, historical data from 2015 to mid-2021 is considered; portfolios are formed as of the first trading day of each year, starting from 2017. Results: Based on the results of the study, recommendations for traders on the use of the considered indicators were formed. Conclusion: The novelty of the study is the obtained results of comparing the effectiveness of individual groups of indicators used in compiling a portfolio in the modern state of the Russian stock market

Building data marts to analyze university faculty activities using power BI

Evaluating the performance of university faculty is a hard task because of the diversity of the work performed. The authors assume that the founder of the university evaluates the effectiveness of the university according to performing the teaching staff. The aim of the study is to improve the monitoring of key performance indicators of the university teaching staff based on data management. The authors present an information system to support decision-making related to the teaching staff at Kemerovo State University. The authors of the paper describe creating such a system using Business Intelligence technologies step by step. The authors identified data sources, designed the structure of the data mart and built ETL-processes for its filling, implemented various analytical dashboards. Implementing the information system in the daily activities of the university allows responding promptly to changes in the key indicators, forecasting their further change, deciding on activation of efforts in the chosen direction or types of work