This study focuses on the development of environmentally sustainable polypropylene (PP)-based composites with the potential for biodegradability by incorporating cellulose and the oligomeric siloxane ES-40. Targeting industrial applications such as fused deposition modeling (FDM) 3D printing, ES-40 was employed as a precursor for the in situ formation of silica particles via hydrolytic polycondensation (HPC). Two HPC approaches were investigated: a preliminary reaction in a mixture of cellulose, ethanol, and water, and a direct reaction within the molten PP matrix. The composites were thoroughly characterized using rotational rheometry, optical microscopy, differential scanning calorimetry, and dynamic mechanical analysis. Both methods resulted in composites with markedly reduced crystallinity and shrinkage compared to neat PP, with the lowest shrinkage observed in blends prepared directly in the extruder. The inclusion of cellulose not only enhances the environmental profile of these composites but also paves the way for the development of PP materials with improved biodegradability, highlighting the potential of this technique for fabricating more amorphous composites from crystalline or semi-crystalline polymers for enhancing the quality and dimensional stability of FDM-printed materials. © 2024 by the authors.

The study of the properties of electrical power sources of ozonators through mathematical models is crucial for satisfying sanitary-hygienic and industrial needs. Ozone is a strong oxidant with disinfectant properties, making its application widespread. However, the efficiency of its production largely depends on the quality of the ozonators' electrical power sources. In this research, we developed and utilized mathematical models aimed at determining the main electrical parameters of various types of ozonators used in ozone production. The results of the study show possibilities for enhancing the energy efficiency of ozonators and optimizing their operational parameters. Mathematical modeling serves as a significant tool for predicting the operating modes and necessary electrical power parameters of ozonators, helping to increase their overall productivity and reduce the cost of ozone production. During the analysis, we considered the stability of the electrical power sources of ozonators, their high-frequency power transmission, and the level of electrical energy consumption. Our research aimed to determine how these parameters affect the ozone production process and, considering these effects, to design and improve the electrical power sources of ozonators. © Published under licence by IOP Publishing Ltd.

It is not uncommon that subways count as densely populated areas, so air quality standards, including fine dust concentration, have been established for them. As passengers and subway staff are exposed to potentially harmful airborne particles, addressing this issue is vital to ensuring a safe and healthy environment on the subway. To reduce the dust concentration in subway systems, the authors propose installing filters to capture dust in ventilation failures between subway tunnels near metro stations. A novel aspect of the proposed method is the fact that airflow will be moved through filters by using the piston action of trains passing through the tunnels. The result of this research provides empirical evidence regarding dust content and mass concentrations of PM2.5 and PM10 in subway environments. While some existing literature discusses air quality in subways, the inclusion of specific measurements and data from the experiment strengthens the understanding of the severity of dust-related air quality issues in such environments. The data for this study were collected in the Almaty subway (Republic of Kazakhstan) at four stations: Raiymbek Batyr, Almaty, Baikonur and Alatau. Measuring points were located on passenger platforms, in the halls and at the entrances to the station. The lab scale tests determined the percentage of particles by their diameters relative to the total volume of dust, the percentage of dust particles smaller than a certain diameter, the percentage of various metal oxides and the average dust density. A preliminary energy assessment has been done on the proposed method of air purification from dust. With a frequency of 24 pairs of trains per hour, the energy savings per ventilation failure will be 240.170 kWh. © 2023 by the authors.

The paper analyzes the main areas of application of mathematical methods in medical diagnostics, formulates principles of diagnostics based on fuzzy logic; developed mathematical models and algorithms that formalize the process of making diagnostic decisions based on fuzzy logic with quantitative and qualitative parameters of the patient's condition; developed mathematical models of membership function. Mathematical models and algorithms have been developed that formalize the process of making diagnostic decisions based on fuzzy logic with quantitative and qualitative parameters of the patient's condition; developed mathematical models of membership functions, formalizing the representation of quantitative and qualitative parameters of the patient's condition in the form of fuzzy sets, used in models and algorithms for diagnosis and finding a diagnosis of assessing the intensity of reactive postoperative edema in patients of all study groups. An expert system was implemented for solving the problems of medical diagnosis based on fuzzy logic when assessing the intensity of reactive swelling of soft tissues, which develops in the postoperative period in patients of all study groups against the background of diabetes. The paper analyzes the main areas of application of mathematical methods in medical diagnostics, formulates the principles of diagnostics based on fuzzy logic. © 2022, Politechnika Lubelska. All rights reserved.

This study explores the optimization of foam ceramic materials through experimental research and mathematical modeling. The goal was to enhance mechanical strength, thermal insulation, porosity, water absorption, and density by adjusting composition and firing conditions. Regression analysis and response surface methodology were used to assess the effects of loam, fly ash content, and the firing temperature. The optimal composition of 60–65% loam, 10% fly ash, and a firing temperature of 950–1000 °C yielded foam ceramics with a bulk density of 680–700 kg/m3, a compressive strength of 3.5–4 MPa, and a thermal conductivity of 0.135–0.140 W/(m·K). Controlled porosity (70–72%) enhanced insulation while maintaining structural integrity. X-ray diffraction confirmed mullite, quartz, and cristobalite phases, with mullite improving mechanical properties. This research demonstrates the potential of optimized foam ceramics for energy-efficient construction. Mathematical modeling and experimental validation provide a pathway for developing lightweight, high-performance ceramic materials. Future work should refine sintering processes, explore new additives, and evaluate the long-term performance. © 2025 by the authors.

One area that holds promise for nuclear energy advancement, which is the most attractive industry for eliminating the imbalance in the energy sector and reducing the world’s energy shortage for the long term, is the replacement of traditional uranium fuel with plutonium fuel. The focus on this research area is due to the growing concern of the world community about the problem of handling spent nuclear fuel, including its further use or storage and disposal. The main aims of this paper are to study the resistance of composite ceramics based on zirconium and cerium dioxide to the hydrogenation processes and subsequent destructive embrittlement, and to identify patterns of growth stability attributable to the occurrence of interfacial boundaries and changes in the phase composition of ceramics. Studies have shown that the main effects of the structural distortion of the crystalline structure of ceramics are caused primarily by tensile deformation distortions, resulting in the accumulation of radiation-induced damage. The formation of Zr0.85Ce0.15O2 tetragonal phase of replacement in the structure of ceramics results in a more than two-fold reduction in the deformation distortion degree in cases of high-dose radiation with protons. The evaluation of the alteration in the strength properties of ceramics revealed that the variation in the phase composition due to polymorphic transformation of the monoclinic Zr0.98Ce0.02O2 → tetragonal Zr0.85Ce0.15O2 type results in the strengthening of the damaged layers and the improvement of the resistance to radiation-induced embrittlement and softening. © 2023 by the authors.

Metal–semiconductor–metal back-contact perovskite solar cells (MSM BC PSCs) with interdigitated metallic electrodes show promise due to their simple structure. However, the power conversion efficiency (PCE) of experimentally obtained MSM BC PSCs is rather moderate. This could be attributed to suboptimal geometric dimensions of electrodes and the poor quality of the perovskite layers in reported devices. In this study, computer simulation methods are employed to investigate the influence of electrode and perovskite layer geometric and electronic parameters on the performance of MSM BC PSCs. The goal is to determine the optimum conditions for achieving high PCE. The findings reveal that the PCE of devices improves as the dimensions of electrodes become smaller. However, significant improvements in PCE are observed when the charge carrier diffusion lengths in the perovskite layer become longer and the work function difference between the electrodes becomes larger. The prediction based on optimal electrode and perovskite layer geometric and electronic parameters suggests that a PCE of around 26% can be achieved with MSM BC PSCs. Findings of this work unveils the hidden potential of MSM BC PSCs and can serve as a theoretical guide to optimize the structure and performance of experimental devices. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.

The growing reliance on fossil fuels is causing significant environmental issues, prompting the search for renewable energy sources. Hydrogen energy, which produces only water vapor, is a promising solution. This study focuses on developing an aluminum-doped SrTiO3 photocatalyst with dual cocatalysts (Rh/Cr2 O3 and CoOOH) for efficient photocatalytic water splitting. Using a simple chemical deposition method, high-purity and crystalline SrTiO3 was synthesized and thoroughly characterized. The results show that the modified SrTiO3 achieved significantly higher photocatalytic activity, with Rh/Cr2 O3/ SrTiO3 @Al/CoOOH producing 11.04 mmol g–1 h–1 of H2 and 4.69 mmol g–1 h–1 of O2. This work demonstrates the effectiveness of dual cocatalyst deposition and aluminum doping in enhancing photocatalytic performance by improving charge separation and reducing recombination. © 2024 The Author(s). Published by al-Farabi Kazakh National University.

The article presents trends in the hydrologic regime of the transboundary river Zhaiyk, and the in the context of anthropogenic and climatic changes. The water regime of rivers is characterized by reduction spring floods and increase the frequency of low-water runoff, especially in winter. The increase in winter runoff likely occurs as a result of climate-caused temperature and precipitation changes. Increasing average annual air temperature are evident both within seasons and from year to year between 1940 and 2019. The changes in runoff and water regime of transboundary Zhaiyk River basin have resulted in decrease in the annual and forecast reduction in river flows for future uses. © 2024, National Academy of Sciences of the Republic of Kazakhstan. All rights reserved.

The kinetics study of Pb2+ and Zn2+ ions adsorption by low-cost mixed Zr-Ca-Mg phosphates with a different Zr/(Ca + Mg) ratio was carried out, for the first time. The effect of chemical composition on adsorption characteristics of obtained adsorbents was established. It was shown that an increase of Ca2+ and Mg2+ cations content in the composition of Zr-Ca-Mg phosphate adsorbents contributed to an increase in the adsorption capacity to Pb2+ (3.82–4.76 mmol/g) and Zn2+ (2.60–4.13 mmol/g) ions. Such improvements in the adsorption capacities were due to the amelioration of the textural properties of adsorbents, so that ABET of adsorbents was in the range of 68–96 m2/g and Vdes BJH of adsorbent was in the range of 0.19–0.24 cm3/g. On the other hand, increase of Ca2+ and Mg2+ cations led to a high difference in solubility products of initial phosphates and spent adsorbents. Kinetic data of Pb2+ and Zn2+ ions adsorption revealed that the adsorption rate is controlled by film diffusion, intraparticle diffusion and chemical interaction, which was confirmed by the results of X-ray diffraction analysis of spent adsorbents and described by the pseudo-second-order model. The increase of zirconium content caused an increase in the rate constant of the pseudo-second-order of Pb2+ and Zn2+ ions adsorption. Intraparticle diffusion had a significant effect on Zn2+ ions adsorption. Due to the suitable kinetics parameters and sorption capacities of composite Zr-Ca-Mg phosphates for divalent metal ions, these sorbents can be recommended as effective materials for heavy metals removal. © 2023 Elsevier Ltd