Recently, flexible perovskite solar cells (FPSCs) fabricated using solution-processed printing techniques have garnered significant attention. However, challenges remain in achieving cost-effective, scalable manufacturing under ambient conditions and ensuring stable, efficient devices. This study focuses on fabricating printed FPSCs using the slot-die coating technique and examines the impact of SnO2 quantum dot (QD) and (6,6)-Phenyl C61 butyric acid methyl ester (PCBM) based electron transport layers (ETLs) on device performance and hysteresis. Experimentally results show that SnO2 QD-based devices exhibited favorable photovoltaic properties but significant hysteresis compared to PCBM-based devices. Numerical simulations have shown that the hysteresis effect in devices is influenced not only by the higher concentration of mobile ions in the perovskite layer of PCBM-based devices compared to SnO2 QD-based devices, but also by the more effective redistribution of these ions during forward and reverse J-V scans. The results provide insights into the behavior of printed FPSCs with different ETLs, contributing to the development of high-performance, hysteresis-free printed FPSCs. © 2024 The Authors

Cyanide compounds, both organic and inorganic, are widely present in natural and industrial environments, especially in effluents from mining and metallurgical processes. Their high toxicity, particularly in the form of free cyanides and hydrogen cyanide, poses severe risks to ecosystems and public health by disrupting cellular respiration via inhibition of cytochrome c oxidase. Conventional chemical treatments such as alkaline chlorination are effective but can be costly, energy-intensive, and generate secondary pollutants. In contrast, microbial bioremediation has emerged as a potentially more sustainable and cost-effective alternative, particularly for on-site treatment of cyanide-laden wastewater from massive tailings dams. Microorganisms including cyanotrophs utilize cyanide as a nitrogen or carbon sources, transforming it into less toxic compounds such as ammonia and carbon dioxide through enzymatic systems like cyanide hydratase, nitrilase, and rhodanese. While bioremediation may operate more slowly than chemical methods, its advantages lie in lower energy consumption, reduced material input, simpler maintenance, and minimized toxic by-products. This review synthesizes current understanding of cyanide's chemical nature, toxicity, and environmental impact, and explores microbial cyanide degradation mechanisms. It further highlights how advances in metagenomics and synthetic biology (“cyanomics”) are enabling the design of more robust biocatalytic systems. Integrating these biological approaches into environmental management frameworks could reduce long-term operational costs and improve sustainability across cyanide-intensive industries. © 2025 The Authors

This article presents the results of developing a model for assessing water quality using the artificial intelligence method. The presented model is based on linear regression, which, when evaluated, revealed a statistically significant interdependence between the combined water quality indicators. It was found that among the measured parameters, the most influential predictor of acidity, conductivity, turbidity and redox potential is water temperature. The discovered relationship between the measured indicators is mainly associated with the influence of temperature on the physical and chemical processes that occur when the temperature of river water increases and decreases. © 2024 IEEE.

Western Kazakhstan is susceptible to desertification, with surface water resource scarcity constraining agricultural development. Groundwater has substantial potential as a reliable and secure alternative to other water resources, particularly for irrigation, which is required to ensure food security. Eight aquifer segments with an exploitable potential of 0.24 km3/year have been identified for the integrated assessment of groundwater’s suitability for irrigation. The assessment criteria included hydro-chemical groundwater characteristics and irrigated land soil-reclamation conditions. The primary objectives of this study were to assess the groundwater quality for irrigation and to develop a practical operation scheme for rational groundwater use in water-saving irrigation technologies and optimize agricultural crop cultivation. Approximately 90% of the groundwater in these aquifer segments was found to be suitable for irrigation, with a total amount of 6520 thousand m3/day and a salinity of up to 1 g/L, and an additional 12,971 thousand m3/day had a water salinity of up to 3 g/L. Only approximately 10% had TDS values above 3 g/L and up to 6.5 g/L, categorized as conditionally suitable for restricted customized agricultural crop irrigation. Irrigated land development by complex soil desalination agro-reclamation operations enabled the use of brackish water for irrigation. The integrated analysis allowed the development of drip irrigation and sprinkling system irrigation schemes that gradually replaced wasteful surface irrigation. The irrigated land prospective area recommended for groundwater irrigation development is 653 km2, with the further restructuring of cultivated areas, reducing the number of annual grasses and grain crops and increasing the number of vegetables, potatoes, and perennial grasses. © 2025 by the authors.

Design and Technology is one of the important subjects taught in secondary or primary schools. However, it is often said that most students are less interested in design and technology subjects. This study was conducted to develop an interactive application based on android in the design and technology subject for the topic of manufacturing technology form 2. The research method of this study was qualitative. The research tool was an interview method. The study respondents consisted of 3 teachers and Design and Technology experts and two design expert lecturers. Study data were collected by recording audio of each interview session conducted by the researcher with 5 respondents and transcribed in Microsoft Word and then categorized into several parts and commented in more detail by the researcher to see the answers given by respondents more clearly. The results of this study found that the developers of this Manufacturing Technology application are well educated. This is because the development of this application will to some extent facilitate the teaching of teachers when PdPc and PdPr take place. In terms of the views of expert teachers and expert lecturers, most respondents gave positive views related to the use of this interactive application in schools compared to negative views, and most gave views resulting from experience while teaching. Some planning suggestions before, during, and after using interactive applications in Learning and Facilitation (PdPc) in Home Teaching and Learning (PdPr) schools were also put forward by expert teachers and expert lecturers for ensuring the use of these interactive applications and it is at an optimal level. The implication of this study is that teachers can improve their skills in using interactive applications in PdPc and PdPr in the future. RBT expert teachers and RBT expert lecturers and teachers in schools are also aware of the importance of the use of these interactive applications in improving students 'thinking skills at a higher level. © 2024 AIP Publishing LLC.

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