THE EFFECT OF SEDIMENT GRAIN SIZE ON HEAVY METAL CONTENT

In the natural surroundings tectonical, climatological, dynamic and physico-chemical conditions of sedimentation are the crucial factors in the process of sediment composition formation. Grain size is one of the most investigated reasons of space and temporary variability in heavy metal concentration. In general, the data on grain size measurement afford to appreciate sorption capacity of sediments and arrange them. The dependence heavy metal content on grain size of sediments has been examined in the enormous amount of research works. The main conclusion is that if grain size decreases, metal content increases.We have carried out sediment grain size measurement of two lakes (Chebachje Lake, Piketnoye Lake) located in the South of Western Siberia, Russia. To define grain size of these sediments the sorting of samples collected layer-by-layer has been conducted by nest of sieves (from 43 to 1000 µm). Accomplished examinations allow to state that layer-by-layer grain size measurement of sediments has significant importance in reconstruction of paleoecologic peculiarities and also influences organic and inorganic matter concentrating in the sediments in dynamic

ТЕХНОЛОГІЇ ХІМІЧНОГО ФРЕЗЕРУВАННЯ АЛЮМІНІЮ ТА ЙОГО СПЛАВІВ: ВИКОРИСТАННЯ ЛУЖНИХ АГЕНТІВ

oai:ojs.journals.kntu.net.ua:article/553Підвищення ефективності технологій хімічного фрезерування алюмінію і його сплавів при спрощення процедури їх здійснення залишається актуальною проблемою. Один з ефективних способів її рішення – розробка нових травильних складів. Мета даної роботи полягала в експериментальному визначенні оптимальних умов використання сольових добавок (NaNO3, NaClO4) в якості компонентів лужних розчинів в технологіях хімічного фрезерування, а також в розробці основ раціонального використання відходів в цих технологіях. Показано, що введення сольовий добавки до лужного розчину хімічного фрезерування збільшує швидкість видалення алюмінію. Якість обробленої поверхні поліпшується, а кількість водню, що виділяється, зменшується. Запропоновано оптимальний хімічний склад травильного розчину. Показано, що з відпрацьованих алюмінатних розчинів можна отримати основну сіль алюмінію A12(OH)5C1, яка має ефективну коагулюючу здатність. Встановлено, що гідроксихлорид алюмінію може бути використаний в якості реагента-висаджувача при декомпозиції алюмінатних лужних розчинів. Запропоновано схему процесу хімічного фрезерування. Вона забезпечує регенерацію компонентів травильного лужного розчину і сприяє раціональному використанню технологічних ресурсів.Ключові слова: хімічне фрезерування, алюміній та його сплави, лужний розчин, сольова добавка, швидкість розчинення. The problem of improving the efficiency of chemical milling technologies while simplifying the procedure for their implementation remains unresolved. One of the efficient ways to solve this problem is to develop new etching compounds. The purpose of this work was to experimentally determine the optimal conditions for the use of salt additives (NaNO3, NaClO4) as components of alkaline solutions in chemical milling technologies, as well as to develop the foundations for the rational use of waste in these technologies. It is shown that the introduction of a salt additive to an alkaline solution of chemical milling increases the rate of aluminium removal. In this case, the quality of the treated surface is improved, and the amount of evolved hydrogen decreases. The optimal chemical composition of the etching solution is proposed. It is shown that the spent aluminate solutions can be used to obtain the basic aluminium salt A12(OH)5C1, which has a high coagulating ability. It has been determined that aluminium hydroxychloride can be used as a precipitating reagent for the decomposition of alkali-aluminate solutions. The scheme of the chemical milling process has been proposed. It provides for the regeneration of the components of the etching alkaline solution and contributes to the rational use of technological resourcesKey words: chemical milling, aluminium and its alloys, alkaline solution, salt additive, dissolution speed

Effects of Amino Acid Side-Chain Length and Chemical Structure on Anionic Polyglutamic and Polyaspartic Acid Cellulose-Based Polyelectrolyte Brushes.

We used atomistic molecular dynamics (MD) simulations to study polyelectrolyte brushes based on anionic α,L-glutamic acid and α,L-aspartic acid grafted on cellulose in the presence of divalent CaCl2 salt at different concentrations. The motivation is to search for ways to control properties such as sorption capacity and the structural response of the brush to multivalent salts. For this detailed understanding of the role of side-chain length, the chemical structure and their interplay are required. It was found that in the case of glutamic acid oligomers, the longer side chains facilitate attractive interactions with the cellulose surface, which forces the grafted chains to lie down on the surface. The additional methylene group in the side chain enables side-chain rotation, enhancing this effect. On the other hand, the shorter and more restricted side chains of aspartic acid oligomers prevent attractive interactions to a large degree and push the grafted chains away from the surface. The difference in side-chain length also leads to differences in other properties of the brush in divalent salt solutions. At a low grafting density, the longer side chains of glutamic acid allow the adsorbed cations to be spatially distributed inside the brush resulting in a charge inversion. With an increase in grafting density, the difference in the total charge of the aspartic and glutamine brushes disappears, but new structural features appear. The longer sides allow for ion bridging between the grafted chains and the cellulose surface without a significant change in main-chain conformation. This leads to the brush structure being less sensitive to changes in salt concentration

Трансформация структуры интеллектуального капитала и рост значимости его составляющих – человеческого капитала и интеллектуальной собственности – в современной экономике

Subject. Currently, as the global economy evolves, its innovative components should demonstrate a tendency of accelerated growth as intellectual capital, information technologies, increasing knowledge and digitization of mushrooming production processes. Nowadays, intellectual capital is one of the economic development drivers. However, the economic community is found to have no generally accepted wording of the concept, thus laying the basis for this article. Objectives. The study sums up the analysis of approaches used by the Russian and foreign economists to determining the economic substance of intellectual capital. We also identify the importance of human capital as its components and specify the definition of the concept. Methods. The article overviews and analyzes proceedings by the most renowned authors, which substantiate how the economic substance of intellectual capital should be unveiled, and suggest its definitions. Results. We specified the definition of intellectual capital concerning the current economic development. We suggest integrating a new component into intellectual capital, such as intellectual property, which includes products of intellectual activity and intangible assets. They can be owned by the entity or other legal entities and individuals, including some employees of the entity. Conclusions. The specified definition of intellectual capital will help address issues of sustainable economic development and ensure the competitiveness of the Russian entities nationwide and worldwide, since it directly contributes to intellectual capital and its components

Characteristics of markets for the creation of innovative products and their impact on the mechanisms of interaction between the subjects of the innovation infrastructure

The article presents the results of a study of the main characteristics of modern markets for the production and sale of innovative products (services, technologies). They made it possible to identify new organizational and economic mechanisms of interaction between the subjects of the innovation infrastructure. As a methodological tool, authors used the main provisions of the theories of interconnections and value chains, cooperation and competition, as well as the Henderson-Clark innovation model. Authors carried out the analysis of the main characteristics of existing and new markets for the production and sale of innovative products (services, technologies). Based on the research, authors concluded that at present there is no universal organizational and economic mechanism for the interaction of subjects of innovation infrastructure in the markets for the production and sale of innovative products (services, technologies). For the successful development of innovation activity, usage of a specific mechanism is subject to a comprehensive justification from the standpoint of each subject of the innovation infrastructure

Развитие человеческого капитала в условиях неопределенности

The high level of uncertainty in the development of the Russian economy at the current stage is predetermined by the negative impact of the Covid-19 pandemic and the growth of sanctions restrictions. The socio-economic consequences of these factors continue to constrain the development of all sectors of the economy and their human capital. The professional activity of almost all specialists has undergone numerous changes. The above circumstances testify to the relevance of the subject of this article in modern conditions. The purpose of the article is to substantiate the key role of the competence Communicative Effectiveness in the formation of human capital in a situation of uncertainty on the example of one of the organizations in the banking sector based on the results of the study. The Assessment Center was used as the main data collection method. In addition, the article used information processing methods, qualitative and quantitative analysis, correlation analysis, visualization of the results. The study of the phenomenon of situation uncertainty using the methodology of the Assessment Center has important advantages over traditional studies using questionnaires. The difference of this study lies in the fact that the situation of uncertainty objectively already exists, and the Assessment Center procedure makes it possible to trace which managerial and professional competencies middle managers use to develop strategies for their behavior. In the course of the study, the key role of the Communicative Efficiency competence in the formation of human capital and the choice of behavior strategies by middle managers in a situation of uncertainty was revealed

Разработка и апробация цифровой модели принятия эффективных инвестиционных решений для формирования стратегий развития экономических субъектов

Subject. Sanction restrictions sharply decreased possibilities to attract external borrowings and substantiated the expediency of internal investments. This necessitated software tools enabling calculations and investment decisions. The developed a digital model of ISPI (Information System Portfolio Investor) will help make smart investment decisions, including at the government level. Objectives. The study aims to build a digital model to identify the most attractive investment areas at the regional, country, and cross-country level. Methods. The ISPI model is based on the Markowitz portfolio theory, the Profitability-Risk Model (PRM), and optimization methods. For our calculations, we used yields on Major and Sector Indices of the UK, India, China, USA, France, South Africa for 2014–2021, in one-month increments. Results. Using the developed ISPI model, we constructed scatter plots of leading stock market indices and identified the leading sectors of national economies of the studied countries and the most attractive investment areas. We solved the problem of finding a global optimum for the studied countries, differentiated the leading economic sectors by the level of investment risk, determined that an international portfolio is the most preferable for investment. Conclusions. Our ISPI model helps investors identify a region or country for smart investments. The model enables to determine industries in which investing is most justified within the nearest investment horizon. The model also helps identify the most appropriate financial instruments for investing in individual countries

Methodological approach to assess the efficiency of the implementation and practical use of the results of scientific research

Accelerated implementation of scientific research results significantly increases the rate of economic growth. However, the complexity and laboriousness of the production of innovative products for various purposes requires the development of new approaches to assess the effectiveness of the processes of its implementation. The article substantiates a modern methodological approach to assess the effectiveness of innovative products. It allows identifying the most promising areas for its implementation, as well as the use of the accumulated scientific potential. In addition, the developed approach makes it possible to assess the significance of the scientific results of scientific, technical and technological programs, systematically analyze the prospects for their application and choose the most effective ways of their practical implementation

Atomistic Molecular Dynamics Simulations of the Initial Crystallization Stage in an SWCNT-Polyetherimide Nanocomposite

Crystallization of all-aromatic heterocyclic polymers typically results in an improvement of their thermo-mechanical properties. Nucleation agents may be used to promote crystallization, and it is well known that the incorporation of nanoparticles, and in particular carbon-based nanofillers, may induce or accelerate crystallization through nucleation. The present study addresses the structural properties of polyetherimide-based nanocomposites and the initial stages of polyetherimide crystallization as a result of single-walled carbon nanotube (SWCNT) incorporation. We selected two amorphous thermoplastic polyetherimides ODPA-P3 and aBPDA-P3 based on 3,3′,4,4′-oxydiphthalic dianhydride (ODPA), 2,3′,3,4′-biphenyltetracarboxylic dianhydride (aBPDA) and diamine 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene (P3) and simulated the onset of crystallization in the presence of SWCNTs using atomistic molecular dynamics. For ODPA-P3, we found that the planar phthalimide and phenylene moieties show pronounced ordering near the CNT (carbon nanotube) surface, which can be regarded as the initial stage of crystallization. We will discuss two possible mechanisms for ODPA-P3 crystallization in the presence of SWCNTs: the spatial confinement caused by the CNTs and π–π interactions at the CNT-polymer matrix interface. Based on our simulation results, we propose that ODPA-P3 crystallization is most likely initiated by favorable π–π interactions between the carbon nanofiller surface and the planar ODPA-P3 phthalimide and phenylene moieties