Ozonation of water is the most effective method of purifying water and preventing its contamination with various harmful and dangerous components. This method is used in urban water supply. During the purification process, ozone is able to oxidize pollutants of any origin to insoluble compounds that are safe for human health. Ozone is a safe substance for chemical water purification. Ozone water purification is widely used today due to the need for deep purification of water for its reuse. This study examines the results of a comparative analysis of the use of ozone and chlorine reagents in water purification processes. The comparative analysis is presented in the following aspects: the laws of ozone solubility in water, the effectiveness of inactivation of microorganisms, corrosion activity, environmental impact assessment at the stages of the life cycle and life cycle cost assessment. In general, ozone technology is one of the modern methods aimed at effectively purifying water from harmful compounds. The use of ozone for water purification ensures the destruction of bacteria, viruses and other harmful microorganisms, as well as reducing the content of organic and inorganic pollutants. One of the main advantages of using ozone is its high oxidizing ability, which increases the purity of water and facilitates the removal of various pollutants. The work carried out a life cycle assessment, which helps to determine the environmental characteristics of various cleaning agents, including their production, preparation of reagents and the immediate stages of the cleaning process. Based on life cycle assessments, it was possible to predict the potential impact on ecosystems and the depletion of natural resources for various categories of impact, which made it possible to justify the choice of the best technology when comparing alternative technologies. Of all the options considered, sodium hypochlorite is the most effective chlorine-containing reagent. The results of the study, compared with chlorine-containing reagents, revealed the most effective method of water purification based on ozone.

Screw compressors are critical equipment in oil and gas production and transportation, where efficiency losses caused by rotor geometry, inlet pressure pulsations, and harsh climatic conditions can accumulate into substantial annual energy penalties and reliability degradation. This study provides a quantitative assessment of these coupled effects within a unified multiphysics framework that combines time-accurate transient CFD simulations based on a fixed Cartesian immersed-boundary formulation with a climate-calibrated offline physics-based digital twin—functioning as a digital shadow with one-way data flow from archival SCADA records—a reduced-order seasonal model with no real-time updating, calibrated against a full calendar year of SCADA records and validated against a held-out cold-season dataset (October–December 2022, Tamb = −15 to +8 °C); summer-period predictions rely on calibrated extrapolation beyond the validation window—an integration not previously demonstrated for oil-flooded screw compressors. Two rotor profile configurations (Type A and Type B) were analyzed to quantify geometry-driven differences in static pressure distribution, leakage tendency, and pulsation sensitivity. Transient suction conditions were modeled using harmonic and quasi-random inlet pressure disturbances to evaluate pressure amplification, phase lag, leakage intensification, and efficiency degradation. Seasonal performance was assessed by integrating temperature-dependent gas properties, oil viscosity behavior, and external heat transfer into an annual climatic load framework. The results show that inlet oscillations are amplified inside the chambers (pressure amplification factor Пp ≈ 1.95; Пp up to 2.3 under quasi-random excitation), reducing mass flow and volumetric efficiency by 8–10% and decreasing polytropic efficiency from 0.78 to 0.69–0.71, while increasing leakage by up to 27% and raising peak contact pressures to 167–171 MPa. Seasonal variability (+30 to −30 °C) increased suction density by 38% but raised drive power by ~9% due to viscosity-driven mechanical losses, producing an energy penalty up to 10.8% and an estimated annual additional consumption of approximately 186 MWh per compressor, decomposed as: cold-season contribution ~113 MWh (±10 MWh, directly field-validated against October–December 2022 SCADA data) and summer-season contribution ~51 MWh (calibrated extrapolation; additional uncertainty unquantified and not included in the ±10 MWh bound). The full annual figure of 186 MWh should be interpreted as a model-based estimate rather than a fully validated result. These findings demonstrate that rotor design optimization and mitigation of nonstationary suction effects, coupled with climate-aware offline physics-based digital shadow operation, represent high-priority levers for improving efficiency and reducing energy penalties in field conditions; reliability implications require further validation against summer-season field measurements.

Relevance. The stability of pit walls is a key factor determining the safety and efficiency of open-pit mining operations. Excessive groundwater inflow and the presence of water-saturated zones often lead to slope instability, landslides, and reduced productivity. Therefore, developing effective methods for dewatering pit wall massifs is of great practical significance for ensuring sustainable mining operations. Objective. The objective of this study was to develop and implement a comprehensive system for draining the pit wall massif using newly designed horizontal and slightly inclined boreholes with camouflet cavities to enhance slope stability. Methods. The research methodology involved advanced groundwater interception in formation zones beyond pit boundaries and interception of surface runoff along pit slopes using horizontal, slightly inclined boreholes with camouflet cavities. Experimental investigations were carried out using a polarization optical setup to analyze stress distribution within the rock mass. Field studies included drilling horizontal boreholes in areas of maximum groundwater accumulation, creating camouflet cavities by controlled blasting, and assessing stress redistribution in the dewatered rock mass. The results demonstrated that camouflet cavities formed beyond the rock mass displacement line act as stress concentrators that effectively unload the near-contour zone and enhance slope stability. The introduction of horizontal, slightly inclined boreholes with camouflet cavities ensures efficient drainage of the contour massif, reduces stress concentrations at the slope base, and stabilizes the overall pit wall structure. The proposed set of measures can be widely applied at mining enterprises under similar geological and hydrogeological conditions, contributing to improved safety and productivity in open-pit mining. © 2025, National Academy of Sciences of the Republic of Kazakhstan. All rights reserved.

В условиях цифровизации и растущей глобальной конкуренции крупные организации Республики Казахстан, такие как «Казатомпром» и «КазМунайГаз», активно внедряют современные подходы к управлению проектами. Использование международных стандартов и моделей таких как Stage-Gate и Project Management System, и интеграция собственных нормативных документов позволяют этим компаниям повышать эффективность реализации проектов, минимизировать риски и обеспечивать устойчивое развитие. В статье сопоставляются две ключевые модели проектного управления c анализом практик управления проектами двух ведущих компаний Казахстана.

В данной работе простым гидротермальным методом синтезированы три типа структур кобальтита цинка ZnCo2O4 на никелевой пене: наностержни, нанонити и пластины. Исследованы морфология и структурные характеристики синтезированных образцов. Выращенные структуры могут быть использованы в качестве основы для бесферментных электрохимических биосенсоров. Методом сканирующей электронной микроскопии (SEM) был проведен детальный анализ серии из шести образцов, синтезированных при различных соотношениях Zn:Co (1:1, 1:10 и 10:1). Результаты исследования элементного состава наноструктур ZnCo₂O₄, синтезированных гидротермальным методом на никелевой пене, показали, что состав полученных материалов коррелирует с составом исходного ростового раствора, подтверждая контролируемость процесса легирования. Отсутствие каких-либо примесей свидетельствует о высокой чистоте синтезированных образцов. Полученные данные подтверждают возможность точного управления стехиометрией кобальтита цинка. Показано, что морфология выращенных образцов зависит от стехиометрии прекурсоров, обеспечивая управляемый рост наноструктурированных материалов. Показано, что гидротермальный метод синтеза наноструктур ZnCo₂O₄ позволяет получать материалы с широким диапазоном стехиометрии от кобальт- до цинксодержащих фаз, что открывает возможности для тонкой настройки эффективных, функциональных свойств ZnCo₂O₄.

Currently, the demand for rare earth elements (REE) has increased significantly due to the expansion of volumes and applications in various industries. The annual increase in consumption of specific elements of rare earths is up to 25% per year. To solve the problem of increasing REE production, it is necessary to involve difficult-to-enrich raw materials in processing, which include the weathering mantle of the Kundybay deposit (Kazakhstan). A special feature of this deposit is the increased proportion (54%) of yttrium oxides, medium and heavy lanthanides. As a result of the conducted research, the granulometric and fractional composition of the ore was determined, which made it possible to determine the distribution of REE by the grain-size class of the ore under study. An analysis of the results showed that 29.35% of REE were contained in the grain-size classes more than 0.02 mm, and 70.65% of REE were in fine class –0.02+0.01 mm, –0.01+0.005 mm and less than 0.005 mm. Large classes were characterized by the presence of grains of minerals of low specific gravity with a reduced REE concentration, which determined the possibility of removing depleted fractions by gravity methods. To assess the possibility of using gravity technology for the enrichment of rare earth ore from the weathering mantle of the Kundybay deposit, a fractional analysis of the machine classes of crushed ore with a size of –2.50+0.315 mm and –0.315+0.10 mm was performed. The results of fractional analysis showed that REE were concentrated in minerals of increased density (more than 2850 kg/m3). Based on the results obtained, the possibility of extracting REE from both its slurry and sand fractions has been determined. For the studied ore of the Kundybay deposit, the use of a combined scheme is proposed, including gravitational enrichment of granular classes and subsequent hydro-and pyrometallurgical processing of enriched granular and slurry classes. Based on the conducted experimental and enlarged technological studies, the use of a bowl centrifugal separator in the process of gravitational enrichment is justified, which allows to intensify the extraction of minerals concentrating rare earth elements from relatively small ore classes. The application of the developed scheme using combined gravity enrichment technology with a combination of screw and bowl centrifugal separators ensures an increase in the content of ΣREE in gravity concentrate from 640 to 1054 g/t with the extraction of ΣREE into concentrate and industrial products of more than 70%. An additional economic effect is achieved by removing final tailings from the enrichment scheme and reducing by 30% the yield of products sent for hydrometallurgical processing.

Полупроводниковые наноструктурированные образцы ZnOи ZnO-GOбыли получены при комнатной температуре методом химического осаждения из раствора.В работе исследовано электрохимическое неферментативное определение аскорбиновой кислоты с помощью полученных наноструктур, нанесённых на стеклоуглеродный электрод. Морфология и структурные свойства изготовленных наноструктурированных материалов были проанализированы с помощью электронного растровогомикроскопа и рентгеновскогодифрактометра. Электрохимические свойствабыли исследованыметодами циклической вольтамперометрии на одноканальном потенциостате-гальваностате. Чувствительность полученных электродовбыла рассчитана для концентрацийаскорбиновой кислотыв фосфатно-буферном растворе от 0,3мМ до 3 мМ при различных скоростях сканирования. Таким образом,было выявлено, что чувствительность образца ZnO-GO ниже, чем у образцаZnO, что может быть связано с диэлектрическими свойствами оксида графена. Однако после отжига в атмосфере чувствительность образца ZnO-GO повысилась, что связано суменьшением дефектов в образце и увеличениемудельной поверхности образцов. В результате исследованийбыл получен модифицированный ZnO-GO/GCE электрод с высокой чувствительностью 386 мкАМ-1см-2,перспективный для использования в качестве основы биосенсора для определения уровнявитамина C вкрови,пищевых продуктах и лекарствах.

Strength and stiffness assessment of rod mechanisms and robotic manipulators is commonly performed using finite element methods (FEM), while motion-induced inertia is often represented by resultant forces and moments applied at link centers of mass. This simplification is inherently approximate because inertial and gravitational forces are distributed along the link and depend on instantaneous kinematics. The main contribution of this paper is a systematic FEM-ready algorithm that extends a previously planar distributed-inertia concept to a formulation applicable to both planar and spatial rod models. The proposed approach computes distributed inertial and weight load intensities in the local coordinate system of each moving rod from kinematic quantities (link orientation, angular velocity/acceleration, and pole accelerations), transforms them into consistent equivalent nodal forces and moments, and assembles them into the global FEM equilibrium system for strength and stiffness calculations. Unlike flexible multibody dynamics formulations (e.g., floating frame of reference formulation (FFRF)/ANCF) absolute nodal coordinate formulation, which primarily target time-domain dynamic simulation, the proposed method is design-oriented and directly produces configuration-dependent engineering outputs-bending moments, axial forces, and longitudinal/transverse displacements-required for link cross-section sizing and stress assessment. The method is demonstrated on a six-bar planar mechanism to illustrate the influence of distributed inertia on internal force and deformation diagrams at low and high driving speeds.

Improving the durability of reinforced concrete sleepers is essential for railway infrastructure exposed to dynamic loading, moisture, and repeated freeze–thaw action. This study proposes a material-level modification approach for heavy concrete for type 2 reinforced concrete sleepers based on the combined use of activated microsilica, a ferroalloy-production byproduct, electrolyzed mixing water, and a polycarboxylate superplasticizer. The novelty of the work lies in the preliminary electrochemical activation of microsilica in an alkaline medium and in the optimization of its joint use with KN-5 by means of second-order experimental design. The concrete was evaluated by compressive and bending strength tests, scanning electron microscopy (SEM), water-penetration testing, and freeze–thaw resistance testing. All modified mixtures outperformed the reference concrete. The highest 28-day compressive strength reached 67.0 MPa, while bending strength reached 7.26 MPa. SEM observations showed a denser and more homogeneous cement matrix with reduced capillary porosity and improved interfacial transition zones. Water resistance improved from W8 for the reference mixture to W10–W14 for the modified concretes. Most modified mixtures achieved a frost resistance grade of F500, and the composition containing 15% activated microsilica and 1.0% superplasticizer reached F550. The proposed approach is effective at the material level for producing heavy concrete with enhanced strength and durability characteristics for reinforced concrete sleeper applications.

Creating a comfortable microclimate in the premises of buildings is currently becoming one of the priorities in the field of architecture, construction and engineering systems. The increased attention from the scientific community to this topic is due not only to the desire to ensure healthy and favorable conditions for human life but also to the need for the rational use of energy resources. This area is becoming particularly relevant in the context of global challenges related to climate change, rising energy costs and increased environmental requirements. Practice shows that any technical solutions to ensure comfortable temperature, humidity and air exchange in rooms should be closely linked to the concept of energy efficiency. This allows one not only to reduce operating costs but also to significantly reduce greenhouse gas emissions, thereby contributing to sustainable development and environmental safety. In this connection, this study presents a parametric assessment of the influence of climatic and geometric factors on the aerodynamic characteristics of the air cavity, which affect the heat exchange process in the ventilated layer of curtain wall systems. The assessment was carried out using a combined analytical calculation method that provides averaged thermophysical parameters, such as mean air velocity (Vs), average internal surface temperature (tin.sav), and convective heat transfer coefficient (αs) within the air cavity. This study resulted in empirical average values, demonstrating that the air velocity within the cavity significantly depends on atmospheric pressure and façade height difference. For instance, a 10-fold increase in façade height leads to a 4.4-fold increase in air velocity. Furthermore, a three-fold variation in local resistance coefficients results in up to a two-fold change in airflow velocity. The cavity thickness, depending on atmospheric pressure, was also found to affect airflow velocity by up to 25%. Similar patterns were observed under ambient temperatures of +20 °C, +30 °C, and +40 °C. The analysis confirmed that airflow velocity is directly affected by cavity height, while the impact of solar radiation is negligible. However, based on the outcomes of the analytical model, it was concluded that the method does not adequately account for the effects of solar radiation and vertical temperature gradients on airflow within ventilated façades. This highlights the need for further full-scale experimental investigations under hot climate conditions in South Kazakhstan. The findings are expected to be applicable internationally to regions with comparable climatic characteristics. Ultimately, a correct understanding of thermophysical processes in such structures will support the advancement of trends such as Lightweight Design, Functionally Graded Design, and Value Engineering in the development of curtain wall systems, through the optimized selection of façade configurations, accounting for temperature loads under specific climatic and design conditions.