In the work the scientific and technical analysis of modern methods of E-waste processing is carried out. It is shown that on the territory of Kazakhstan there are no E-waste recycling technologies. The relevance and importance of collection and processing of E-waste increases with the fact of lack of application of rational technology of their processing. Many valuable, technologically recoverable metals are lost irretrievably. The results of the chemical composition of the crushed product — computer boards of computers, which were used as an object of research for gold extraction from them, are presented. The results of studies of qualitative assessment of initial E-waste showed a wide range of changes in metal compositions. Precious metals in the studied E-waste are represented by Au, Ag and Pd, the average content of which is 225, 425 and 15 ppm, respectively. The paper presents the scheme of the laboratory installation and the methodology of low-temperature chloridizing roasting of E-waste with gaseous chlorine. Comprehensive studies of the chemical and phase composition of the solid residue obtained after the experiment using the SEM instrument (Leo Supra Carl Zeiss AG, Germany) and Agilent 7700 Series ICP-MS (Agilent Technologies, USA), Rigaku, Ultima III (Rigaku Corporation, USA) showed the presence of metal chlorides and amorphous phase representing unburned parts of plastic and other organic compounds in them. The quantitative ratio of solid and amorphous phase in the obtained solid residue is 31.5% and 69.5%, respec-tively. The phase composition of the solid residue was determined: 5.4% CuCl2; 7.8% FeClO and 17.2% Cu2 Cl(OH)3. As a result of the experiments, the optimal process parameters were established: temperature — 250о C, duration — 30 min, chlorine consumption —150 ml/min. It is established that at optimum firing parameters high up to ~98% of gold extraction from E-waste in the form of gaseous sublimate of gold chlorides is achieved.

Background Arterial hypertension (AH) and post-COVID synrome poses a rising challenge in low and middle-income countries, with uncertain prevalence in Kazakhstan’s older adults population. Objectives This study investigates the effectiveness and safety of transitioning older adults patients (65 and older) from multiple antihypertensive medications to a “single tablet” strategy, aiming to evaluate its effect on patient conidion and identify factors influencing dose adjustments. Design A prospective cohort study with a follow-up of 8 week. Participants There were enrolled 98 patients, categorizing them by age groups 65-74 years and 75 and older. Intervention One-moment isolated deprescribing of hypotensive drugs to “one tablet” therapy. Measurements Endpoints were assessed over three visits in eight weeks, utilizing statistical analysis with significance set at p < 0.05. Results Older patients exhibited a trend of higher education, lower smoking rates, and lower average weight. Transitioning to a single-tablet strategy led to a significant reduction in hypertensive crises and adverse events. While therapy adherence improved initially, it decreased by 10% by the 8th week. Factors influencing therapy changes were identified through subgroup analysis. Conclusion This study provides valuable insights into transitioning older adults patients to a “single tablet” strategy, underscoring the importance of personalized approaches based on identified influencing factors. © The Ibn Sina Trust.

This research explores the application of gravel filters in oil wells to mitigate sand production. The study focuses on a novel approach utilizing a bitumen-based binder to create a durable and efficient gravel pack. A comprehensive review of traditional gravel filter designs and their limitations is presented. Experimental results demonstrate the improved strength and stability of the bitumen-bound gravel pack, as well as its controlled dissolution rate in hydrocarbon environments. This innovative solution offers several advantages, including enhanced well productivity, reduced maintenance costs, and improved environmental performance. The paper concludes by discussing the potential applications and future research directions for bitumen-bound gravel filters in the oil and gas industry. The recommended gravel filter design, utilizing a gravel-bitumen mixture, is proposed to enhance efficiency and reliability in oil and gas well operations.

This review article focuses on the study of carbon materials utilized as electrodes in lithium-ion batteries and supercapacitors. The research examines three primary categories of materials: activated carbon, carbon aerogels, and nanoporous carbon. The article provides a comprehensive explanation of the operational principles of many types of capacitor systems, such as double-layer electrochemical capacitors, pseudo capacitors, and hybrid capacitors. The carbon materials under discussion are thoroughly examined with a focus on their synthesis processes, structural features, and electrochemical properties. The study investigates the impact of pore structure, surface area, and the presence of functional groups on electrode performance. The impact of heat treatment and chemical modification techniques on the properties of synthesized carbon structures has been investigated, specifically examining parameters such as temperature and duration. The text examines the benefits and drawbacks of each material type, taking into account their individual capacity, cyclical stability, and economic efficiency. The study emphasizes the importance of precise adjustment of the synthesis process to enhance the electrochemical characteristics and showcases the possibility of employing these materials in sophisticated energy storage devices. This review serves as a crucial resource for experts engaged in developing cutting-edge materials for lithium-ion batteries and supercapacitors. It also highlights potential topics for future research in the realm of electrochemical energy storage. © 2024 E.A. Buketov Karaganda University Publish house. All rights reserved.

Currently, ecological energy production is one of the most pressing issues in power engineering. In addition, environmental pollution caused by various emissions and the challenge of waste disposal remain significant global concerns. One potential solution to these problems is the conversion of waste into useful energy through combustion. In this study, experimental investigations were carried out on the combustion of municipal solid waste (MSW) in a grate furnace of a 400 kW hot water boiler. The experiments included the combustion of both MSW and traditional brown coal. Data were collected on the concentrations of various substances in the exhaust gases, and thermal imaging was performed to assess heat losses from the boiler surface. When burning waste compared to coal, SO2 concentrations were significantly lower, ranging from 3.43 to 4.3 ppm, whereas for coal they reached up to 122 ppm. NOX concentrations during MSW combustion peaked at 106 ppm, while for coal combustion they reached 67.5 ppm. A notable increase in CO concentration was observed during the initial phase of coal combustion, with levels reaching up to 2510 ppm. The thermal efficiency of the boiler plant reached 84.4% when burning waste and 87% when burning brown coal. © 2025 by the authors.

Introduction. Traditional machining methods for these components often face challenges related to high labor intensity, tool wear, and insufficient surface quality, especially when producing tooth gaps. The thermofrictional treatment method offers a promising alternative to improve efficiency and surface characteristics without compromising structural integrity. The aim of this study is to evaluate the feasibility and effectiveness of thermofrictional treatment in machining the tooth gaps of large-modular cylindrical gears, replacing the conventional rough milling stage with a more resource-efficient approach. Materials and methods. Experimental trials were conducted on 40Х steel blanks. Surface roughness was measured using a portable profilometer TR 100. The process was modeled using DEFORM 3D software. Cutting parameters included feed rates (S) from 0.13 to 2.08 mm/rev and spindle speeds (n) from 200 to 2000 rpm. Results. Experimental findings revealed that feed rate is the dominant parameter influencing surface roughness. Increased feed results in higher surface irregularity, while excessive reduction reduces processing efficiency. Higher spindle speed improves surface finish due to more stable chipformation. Optimal conditions were identified as S = 0.52 mm/rev and n = 2000 rpm. Simulation results showed that increasing spindle speed raises contact temperature (up to 2660°C) while reducing the depth of thermal penetration into the workpiece, resulting in localized thermal effects. Discussion. The study confirms that thermofrictional processing effectively replaces conventional rough milling, offeringacceptable surface quality and reduced manufacturing complexity. The thermal behavior at the interface plays a crucial role in achieving the desired surface integrity and must be controlled to avoid subsurface damage. Conclusion. Thermofrictionaltreatment using a specially developed disc cutter can be effectively applied to machine tooth gaps in large-modular cylindrical gears, achieving the required surface roughness while improving process efficiency. Resume. The method provides a viable and energy-efficient alternative to traditional machining operations for heavy-duty gear components. These results can be applied in gear manufacturing and repair facilities serving the mining and heavy equipment sectors. Further research should focus on analyzing hardness changes in the treated layer and optimizing heat distribution for various steel grades. © 2025, North Caucasian Institute of Mining and Metallurgy, State Technological University. All rights reserved.

In the article there is a review of world experience in the study of pollution of water bodies, including plastic particles. To date, the problem of plastic pollution has become global. Plastic pollution is a relevant and relatively new direction. The term "plastic" is a generalized name for the family of synthetic polymers. Plastic is a highly demanded material, which is used in all sectors of the economy for various reasons such as low cost, durability, etc. At the same time, it has a negative impact on the environment and impacts humans and living organisms by entering the food chain. Scientists classify plastic into micro- and macro-plastic according to particle size. Analysis of the study of plastic pollution leads to the conclusion that the smaller the size of the particles, the greater their impact on the pollution of water bodies. The difficulty of assessing plastic pollution is the lack of a unified recommended methodology. The study of MP problems in continental water bodies, including its possible concentrations, interaction with hazardous chemical compounds and impact on biota, is just beginning to be investigated. In this situation, it is reasonable to recommend the inclusion of micro- and macroplastics as one of the components of the program for monitoring the qualitative condition of surface waters. © 2023, National Academy of Sciences of the Republic of Kazakhstan. All rights reserved.

Cellulose-based composite materials have attracted increasing interest among scientists working on developing energy-storage materials with unique properties. In the present study, an aerogel was synthesized from sunflower seed husk (SFH) to form microcrystalline cellulose (MCC), the hydrogen (H2) sorption potential of which was then investigated. The effect of MCC concentration on the nitrogen sorption capacity of the aerogel samples obtained was assessed based on comparison with other like materials. As per the results of BET analysis, the aerogel with an MCC concentration of 3% was determined to be microporous, with a specific surface area of 3000 cm2/g, average pore diameter of 29.7 nm, total pore volume of 0.44 cm3/g, density of 166 kg/m3, and porosity of 95%. It was found that at a temperature of 77 K and up to 1 bar, MCC3/polyacrylamide (PAm) aerogel can sorb up to 0.8% hydrogen. Additionally, the results of SEM analysis revealed a microporous surface morphology, while FTIR analysis showed that the hydroxy groups in the MCC molecule and the amino groups in the PAm molecule form hydrogen bonds with each other. The results of the research indicate that such an aerogel has potential for use as a material for H2 storage, and appears to be more ecologically friendly than the metal hydrides used in many H2 fuel cells and storage containers, the end-of-life processing of which remains a relatively unexplored issue. Generally, cellulose is considered to be a highly desirable material from both ecological and economic perspectives. © The Author(s), under exclusive licence to Springer Nature B.V. 2025.

The study presents a scenario analysis of the long-term dynamics of the water level of Lake Balkhash, one of the largest closed lakes in Central Asia, taking into account climate change according to CMIP6 scenarios (SSP2-4.5 and SSP5-8.5) and socio-economic factors of water use. Based on historical data (1947–2021) and a water balance model, the contribution of surface runoff, precipitation and evaporation to the formation of the lake’s hydrological regime was assessed. It was established that the main source of water resources for the lake is the flow of the Ile River, which feeds the western part of the reservoir. The eastern part is characterized by extremely limited water inflow, while evaporation remains the main element of water consumption, having increased significantly in recent decades due to rising air temperatures. Increasing intra-seasonal and interannual fluctuations in water levels have been recorded: The amplitude of short-term fluctuations reached 0.7–0.8 m, which exceeds previously characteristic values. The results of water balance modeling up to 2050 show a trend towards a 30% reduction in surface inflow and an increase in evaporation by 25% compared to the 1981–2010 climate norm, which highlights the high sensitivity of the lake’s hydrological regime to climatic and anthropogenic influences. The results obtained justify the need for the comprehensive and adaptive management of water resources in the Balkhash Lake basin, taking into account the transboundary nature of water use and changing climatic conditions. © 2025 by the authors.

Critical infrastructure has a paramount role in socio-economic development, and its disruption can have dramatic consequences for human communities, including cascading impacts. Assessing critical-infrastructure exposure to multiple hazard is therefore of utmost importance for disaster risk reduction purposes. However, past efforts in exposure assessment have predominantly concentrated on residential buildings, often overlooking the unique characteristics of critical infrastructure. Knowing the location, type and characteristics of critical infrastructure is particularly challenging due to the overall scarcity of data and difficulty of interacting with local stakeholders. We propose a method to assess exposure of selected critical infrastructure and demonstrate it for Central Asia, a region prone to multiple hazards (e.g., floods, earthquakes, landslides). We develop the first regionally consistent exposure database for selected critical infrastructure and asset types (namely, non-residential buildings, transportation and croplands), assembling the available global and regional datasets together with country-based information provided by local authorities and research groups, including reconstruction costs. The method addresses the main known challenges related to exposure assessment of critical infrastructure (i.e., data scarcity, difficulties in interacting with local stakeholders) by collecting national-scale data with the help of local research groups. The analysis also includes country-based reconstruction costs, supporting regional-scale disaster risk reduction strategies that include the financial aspect. © 2024 Copernicus Publications. All rights reserved.