The increasing demand for rare refractory metals such as niobium in high-tech industries requires the development of efficient and sustainable methods to extract them from secondary sources, including industrial by-products. This study studied niobium extraction from a fluoride-sulfuric acid solution obtained by leaching a niobium-containing intermediate product. A comprehensive assessment of various organic extractants, including methyl isobutyl ketone, tributyl phosphate, trioctylamine, and Cyanex 923, was performed, focusing on the recoverability of niobium from this solution. Experimental results show that Cyanex 923 is significantly superior to other extractants in efficacy. The extraction of niobium at different concentrations of this extractant in toluene and the ratios of organic and aqueous phases were studied. It is established that an increase in the contact time of the phases does not contribute to additional niobium recovery. Studies show that applying concentrated Cyanex 923 in toluene ensures complete recovery of niobium into the organic phase. The three-stage counter-current extraction shows a slightly higher niobium recovery efficiency than the single-stage process. © 2024, Technical University of Kosice. All rights reserved.

In this study, an AM-based continuous processing reactor system was designed, manufactured, and assembled on a laboratory scale for the generation of pharmaceutical substances with an improved process control. The developed AM-based (additively manufactured) continuous pharmaceutical reactor system for the synthesis of metronidazole derivatives aimed to optimize both the physical and the chemical processes with time savings. Using AM, we were able to build reactor subcomponents with complex designs and precise dimensions, which facilitated the precise control of the reaction parameters and reduced the amount of chemicals required compared to macroscale reactors. The assembly of the whole reactor system consisted of main reactor bodies, mixers, valves, heat exchangers, electrical motors, and a microcontroller system. The assembled reactor system revealed a continuous flow of reagents and ensured uniform mixing and reaction conditions, thereby increasing the process efficiency and product quality. Five metronidazole derivatives were synthesized via two continuous processes, involving metronidazole reduction and its subsequent reactions with terephthalic aldehyde and anthracen-9(10H)-one to form Schiff bases. The optimal conditions were determined as follows: compound A (72% yield, 120 min, 55 °C), compounds B and C (63% and 68% yield, respectively, 8 h, 65 °C), and compounds D and E (74% and 85% yield, respectively, 8 h, 45 °C). © 2024 by the authors.

Water scarcity is a major issue in cities situated at the Caspian regions of Kazakhstan. To overcome this issue, two compression heat pump-assisted solar thermal desalination configurations are proposed in this research. A numerical model using the TRNSYS simulation package was developed to predict the energy performance of the proposed systems and was validated with experimental results available in the open literature. The influence of ambient parameters and water depth in the basin of a solar still and insulation thickness was analyzed. The performance of proposed configurations is compared with conventional solar still. The errors noticed at 2 and 10 cm depths are 23.6% and 12.1%, respectively. The simulation results confirmed that the heat pump-assisted regenerative solar still configuration has a 91.1%, 73.0%, 61.6% and 82.6% improved productivity during winter, spring, summer and autumn climates, respectively. The results confirmed that significant improvement in freshwater production was observed with heat regeneration compared to the configuration without heat regeneration. The maximum freshwater production with heat regeneration reached 18.0 kg m−2 day−1 in summer and 9.0 kg m−2 day−1 in winter. The optimal water depth in the basin is observed to be in the range between 0.5 and 2.0 cm, while the insulation thickness is between 5.0 and 7.0 cm. The results confirmed that the proposed configuration satisfies the water requirements in Kazakhstan. © Akadémiai Kiadó, Budapest, Hungary 2024.

The natural environment of large cities is subject to strong anthropogenic pressure. Both the soil and the hydrosphere are exposed to pollution. At the same time, the atmosphere is one of the mechanisms means for the transfer pollutants that enter living organisms. The study of distribution routes, chemical reactions and interaction with the biosphere of released into nature substances and their compounds help to find means to minimize the negative impact to the environment. One of the ways to reduce costs is to find the best options for solving environmental problems. Such solutions are not possible without monitoring of pollutant emissions and environmental analytical control in particular. For the city of Almaty and the adjacent territory, for the first time in 2018-20, a research program on heavy metal pollution was carried out. This project made it possible to study the changes dynamics in soil and snow cover concentrations of the following elements: Copper (Cu), Zinc (Zn), Nickel (Ni), Lead (Pb), Cobalt (Co), and Cadmium (Cd). Along with the lithosphere, the water area of Kapshagay reservoir was studied. In addition, there was obtained the data on oxidizability, acidity, salinity and suspended solids. The dynamics of pollution by polychloryl biphenyl compounds has also been studied. The metals concentration was determined by the flame atomic absorption spectrometric method. The presence of these chemical elements in the lithosphere allowed assuming the presence natural sources of pollution against the background of anthropogenic factor exclusion. The lead content occupies a special position, since the presence of anthropogenic source is not excluded and requires further research and evaluation of the components of the incoming part of this chemical element balance. The article provides an analysis of the search for a source of copper pollution of the snow cover in Almaty agglomeration territory. The source of copper emissions is assumed to be of natural origin. Based on the analysis of the wind regime, the location zones of sources of lithosphere pollution by copper are potentially determined. The study of the location of areas free from snow cover during the period of increasing copper concentration will allow determining more accurate location of zones producing the copper particles transfer. © 2023, National Academy of Sciences of the Republic of Kazakhstan. All rights reserved.

It is difficult to reuse wastes from polymers due to the mismatch between the amount of contaminants and the secondary polymers and the quality of the feed. This type of operation is much more expensive and cost-effective than the production of polymer raw materials from the latest materials. However, the reuse of recyclable polymers is beneficial if used extensively in the production of various concrete products and wood-polymer boards. This is done only if cleaning and sorting are not particularly important for the production of polymer products. Polyethylene terephthalate (PET) is a widely used polymer in various industries due to its excellent physical and chemical properties. Besides, the increasing use of PET products has led to a global crisis in waste management, as improper disposal of products has caused significant environmental damage. PET is a major source of accumulated waste in landfills, and to address this issue, recycling methods have evolved. In this regard, the present review examines various techniques involved in the recycling of PET. Conventional recycling methods and the influence of diverse depolymerization reaction variables were discussed, and the upsides and downsides of each technique were considered. The review summarizes major advances in recycling technologies for plastic waste, focusing on the bio-recycling of PET, aiming for sustainable, economical solutions in the circular economy. © 2024 The Authors

Centrifugal pumps are vital components in various industrial and domestic applications for fluid transportation. Understanding the complex hydrodynamic behavior inside these pumps is crucial for their efficient design and operation. This study presents a detailed hydrodynamic analysis of a single-stage single-suction centrifugal pump using computational fluid dynamics (CFD) techniques. The focus is on modeling turbulent flow phenomena within the pump to improve its performance and energy efficiency. The numerical simulations are conducted using ANSYS CFX software, which allows for a comprehensive examination of the pump’s internal flow characteristics. The study investigates the effects of impeller design, blade angles, and operating conditions on the pump’s efficiency and hydraulic performance. The results highlight the importance of accurate numerical modeling in optimizing pump design and achieving higher efficiency. This research contributes to the advancement of centrifugal pump technology by providing insights into the complex flow dynamics. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

As the matter of fact, the Caspian Sea is an inland water structure that has no physical connection with the World Ocean, and has a high sensitive level for changes in various aspects. The live activity and mineral resources near the Caspian Sea was organized on the basis of the economic views of the states located on its coast since ancient times. Two-thirds of the earth's surface is covered by water ecosystem, and more than half of humanity is concentrated in a strip 50 miles wide along the coast. We are intimately connected to vast areas of water, and the health and quality of life in our oceans has a direct impact on the health of our lives. Systematic monitoring of water bodies should be an organizational and technological scheme for regular and continuous observations, assessment and forecasting of the state of water resources under the influence of natural and anthropogenic factors. The main purposes of monitoring are supplying water management and environmental complexities with reliable and latest updated information that allows scientists to assess the functional integrity of the state of ecosystems, and additionally, identify the causes of changes and evaluate their consequences of determination of corrective measures. Supportive information of that artificial reservoirs research should contain a large amount of various options and data on the physical-geographical and socio-economic features of the regions adjacent to the reservoir. This paper describes a state of knowledge of the dynamic evaluation of the coastline of the Caspian Sea region today, as well as the consequences may affect to the future economical situation of that area. Analysis of this research is devoted to the study of the practical application of photogrammetric methods and coastline monitoring technologies, using system of satellite images with high spatial resolution. The results of that observation reveal the high technological efficiency and comparison of the proposed methods with indication of updated techniques productivity. © 2023, National Academy of Sciences of the Republic of Kazakhstan. All rights reserved.

This research aims to evaluate the impact of implementing digital twins on companies’ operational activities in terms of enhancing their efficiency. Research methods include data analytics and visualization to explore the intricacies of creating and utilizing digital twins among high-tech leaders, as well as the correlation between expenses on innovative digital twin solutions and company revenues, followed by clustering to assess the impact of costs associated with the development and implementation of digital twins on enhancing the efficiency of business operational activities. In this context, the research presents a novel approach to measuring the influence of digital twin implementation on the efficiency of operational activities of high-tech companies based on correlation and cluster analysis. The findings indicate that all selected high-tech companies analyzed successfully applied digital twins to enhance their operational efficiency, as evidenced by the high correlation coefficient between expenses on digital twins and company revenues. Cluster analysis, distinguishing between two clusters of leaders and followers in the use of digital twins, allowed for identifying some distinctive characteristics of a leader in digital twin utilization and presenting a vision for transitioning to management based on the digitization of all company business processes. © 2024 Informa UK Limited, trading as Taylor & Francis Group.

Currently, due to the high rate of development of the rare-earth industry, new sources of raw materials are being mastered and new technologies for obtaining rare-earth metals (REM) are being developed. Studies have shown that REM in kaolinite clays of Alexeevskoe deposit in Kazakhstan and Egypt deposits in Sinai Peninsula (K-Watt, K-Tech) and in Aswan region (KB,KPL) are mainly represented by erbium (Er). Production of Er concentrate is considered as a by-product in a comprehensive middlings processing of kaolinite clays to produce alumina and building materials. The possibility of obtaining Er concentrate by sulfuric acid leaching and sorption concentration methods has been determined. Optimal technological conditions of kaolinite clays leaching is the use of 5% solution of H2SO4, at temperature 50 °C, duration 60 min and L:S ratio = 5. Under these conditions the separation of REM from the main components Fe2O3, Al2O3, SiO2 is achieved. Concentrates were obtained with the content of the sum of REM oxides from 91.3 to 93.4%, in which the relative content of Er was from 64.89 to 90.82%. The results showed that the developed technology can be used for processing of erbium-containing kaolinite clays of various deposits. © 2023 The Authors

Assessing glaciers using recent and historical data and predicting the future impacts on them due to climate change are crucial for understanding global glacier mass balance, regional water resources, and downstream hydrology. Computational methods are crucial for analyzing current conditions and forecasting glacier changes using remote sensing and other data sources. Due to the complexity and large data volumes, there is a strong demand for accelerated computing. AI-based approaches are increasingly being adopted for their efficiency and accuracy in these tasks. Thus, in the current state-of-the-art review work, available research results on the application of AI methods for glacier studies are addressed. Using selected search terms, AI-based publications are collected from research databases. They are further classified in terms of their geographical locations and glacier-related research purposes. It was found that the majority of AI-based glacier studies focused on inventorying and mapping glaciers worldwide. AI techniques like U-Net, Random forest, CNN, and DeepLab are mostly utilized in glacier mapping, demonstrating their adaptability and scalability. Other AI-based glacier studies such as glacier evolution, snow/ice differentiation, and ice dynamic modeling are reviewed and classified, Overall, AI methods are predominantly based on supervised learning and deep learning approaches, and these methods have been used almost evenly in glacier publications over the years since the beginning of this research area. Thus, the integration of AI in glacier research is advancing, promising to enhance our comprehension of glaciers amid climate change and aiding environmental conservation and resource management. © 2024 by the authors.