This article deals with the research and analysis of electric motors and their matched transmission systems within the context of a versatile electric mini-tractor designed for tasks such as street cleaning, urban park maintenance, and transportation of small loads. The primary objective of the research is to assess the strengths and weaknesses of several electric motor and transmission combinations designed to meet the specific operational demands of the tractor. As the driveline has to provide substantial torque while maintaining optimal operating conditions and avoiding overheating, a series of experiments were conducted, covering various electric motor configurations operating within the 60V range, with power outputs ranging from 1000 to 1500 watts and including multiple gearbox variations. A comparative analysis was performed to assess the advantages and disadvantages of direct chain drive transmission solutions without a differential on a rigid axle, in contrast to a sealed motor-gearbox unit featuring differential and semi-axles. The results of this research were used for mathematical comparison of the driveline solutions, enabling the detection of optimally matched transmission and motor solutions. The experiments also covered the identification of energy-efficient solutions and optimal design parameters for an electric tractor explicitly designed for continuous operation exceeding 10 hours, with cargo capacity exceeding 500 kg, high offroad maneuverability, and a service life exceeding 5000 hours. The dynamic tests carried out during the research have provided valuable insight into the relation of the overall power efficiency of the vehicle to the weight and transmission ratio variations. © Faculty of Mechanical Engineering, Belgrade. All rights reserved

Today, there is a steady trend in the use of carbon fiber-reinforced plastics in the aerospace and defense industries, mainly based on using pre-impregnated semi-finished products - prepregs. Producing carbon fiber parts from prepregs often requires a long manufacturing time, during which the prepreg must maintain its performance properties. Therefore, one of the main characteristics of prepreg is its viability. This work developed a suitable resin composition with optimized properties and a methodology for studying the viability of prepreg samples, based on determining the stickiness and degree of curing of the prepreg depending on storage time. The influence of prepreg storage time on the strength characteristics of cured laminates was studied. Prepreg samples with long-term viability of up to 60 days were obtained. The experimental data obtained are of practical significance in the industrial production of carbon fiber products, as they establish a connection between the performance properties of the prepreg and storage time. © 2023 E.A.Buketov Karaganda State University Publish House. All rights reserved.

The rapid expansion of phosphorus production has emerged as a critical environmental issue, disrupting the balance between industrial growth and ecological stability. Kazakhstan, as a leading phosphorus producer, faces significant challenges due to the environmental impact of activities in the Karatau phosphate basin. This study evaluates the environmental consequences of Kazphosphate LLP's operations in Karatau, focusing on air quality, surface water pollution, heavy metal contamination in soil, and the formation of young soils at industrial waste sites. Key findings include elevated zinc levels in soil samples, exceeding the maximum permissible concentration by up to 12 times, and low concentrations of copper. The air quality in Karatau showed low pollution levels, with hydrogen sulphide (H2S) at acceptable limits (SI = 0.9). The water bodies, particularly the Talas and Assy rivers, exhibited moderate pollution, with magnesium and sulfates as primary contaminants. Soil analysis highlighted the slow progression of natural recovery, with higher humus and mobile phosphorus content in the upper layers, but deficiencies in nitrogen and exchangeable potassium. This research underscores the urgent need for sustainable waste management practices, reclamation strategies, and advanced technologies to mitigate the environmental impact of phosphorus production. The findings aim to inform measures to reduce pollution, enhance ecosystem restoration, and promote the long-term sustainability of the Karatau phosphate basin.

It is known that the process of water treatment in surface water bodies requires the development of advanced and effective technologies for the destruction of harmful microorganisms and viruses. The aim of the present study is to develop a method for the investigation of surface water content. As a result of the study, the electronic circuit of the purification device using ultraviolet rays was developed. The energy and spectral characteristics were experimentally investigated and the economic efficiency of the ultraviolet ray device was determined, taking into account the basic sanitary and hygienic requirements for the organisation of ultraviolet water disinfection. It is substantiated, that the developed scheme provides safety of conditions of work of the personnel with the equipment. © 2025 The Author(s). Published by Vilnius Gediminas Technical University.

The main objective of this work is to study the influence of structural changes in ZrO2 ceramics on the resistance to hydrogenation processes arising from testing the performance of ceramics as materials for solid oxide fuel cells. During the conducted studies, it was established that the use of stabilizing additives MgO and CaCO3 to initiate processes of polymorphic transformations in ZrO2 ceramics makes it possible to increase the resistance of ceramics to hydrogen swelling due to the stabilization of the crystal structure, the change of which is associated with polymorphic transformations. Suppression of volumetric swelling processes due to polymorphic transformations caused by the addition of stabilizing additives made it possible to elevate resistance to hydrogen absorption and destabilization of the near-surface layer by preventing hydrogen agglomeration processes in the near-surface layer. It has been determined that the modification of ZrO2 ceramics by initiating processes of polymorphic transformations of the type m-ZrO2 → t – ZrO2 and m-ZrO2 → c-ZrO2 leads not only to an increase in strength indicators, but also to an increase in resistance to embrittlement processes during hydrogenation and high-temperature degradation.

This paper presents the history of the development of heterojunction silicon solar cells from the first studies of the amorphous silicon/crystalline silicon junction to the creation of HJT solar cells with novel structure and contact grid designs. In addition to explanation of the current advances in the field of research of this type of solar cells, the purpose of this paper is to show possible ways to improve the structure of the amorphous silicon/crystalline silicon-based solar cells for further improvement of the optical and electrical parameters of the devices by using of numerical simulation method and current hypotheses. This paper briefly describes the history, beginning from the first studies of and research of HJT-structure solar cells. It raises questions about the advantages and existing problems of optimization of HJT solar cells. The authors of this paper are proposing further ways of design development of HJT solar cells. © 2023 by the authors.

The article analyzes approaches to the use of cloud technologies in the process of teaching students at large universities. The model of the academic cloud of a modern university is considered. Examples of software and functional platforms that meet the needs of students in electronic learning resources are given. The deployment models of the cloud-oriented educational environment that includes private cloud infrastructure as a service (IaaS) and platform as a university service are analyzed. The cost of deploying an academic cloud based on the educational institution's infrastructure and renting infrastructure from a vendor is compared. A multifactorial model for evaluating investment options in the university cloud in the context of fuzzy information is proposed. In contrast to the known approaches to solving such a problem, our model assumes that the dynamics of the financial states of the players are set through a system of discrete equations. These equations describe the dynamics of multidimensional variables. The latter made it possible to consider the general problem of investing in the academic cloud within the framework of a game scheme for tasks in a fuzzy formulation, with the financial resources (FR) available to the educational institution. Preference sets and optimal financial allocation strategies for building an academic cloud are found. © 2024 This is an open access article under the CC BY-SA license

This study aims to synthesize and characterize a fumarate-Al-based Metal-Organic Framework (Al-Fum MOF) to evaluate its adsorption properties towards two organic dyes, namely: Indigo Carmine (IC) and Orange II (OII). The Al-Fum MOF was synthesized by a non-solvothermal method and characterized by XRD, FTIR, EDX, TGA, N2 sorption and pHPZC. The results of this work show that the pseudo-second-order model better describes the adsorption process for both dyes. The plausible mechanisms reveal a duality between the physisorption phenomenon and physicochemical interactions, the latter being predominant. The optimal conditions for adsorption were determined using centered composite experimental designs, resulting in error percentages below 2 %: for IC (pH 3, concentration of 84.7 mg/L and adsorbent mass of 25 mg) and for OII (pH 3, concentration of 100 mg/L and adsorbent mass of 25 g). The adsorbed amounts were 33.8 and 22.9 mg/g for IC and OII, respectively. The regeneration of Al-Fum MOF was studied and the results suggest that the material can remain active during several use cycles. This study contributes to the advancement of knowledge on adsorbent materials for wastewater treatment and highlights the potential of Al-Fum MOF for practical applications. However, further studies are needed to evaluate the application of Al-Fum MOF to real and complex wastewater. © 2025 The Author(s)

The article presents an innovative approach to the restoration and stabilization of weak soils, using the example of the Turkestan region, characterized by an arid climate and degraded soil cover. The main goal of the study was to develop and experimentally validate a biostabilization technology aimed at improving the physico-chemical and engineering-geological properties of soils through environmentally safe compositions. This technology addresses challenges such as erosion, low bearing capacity, and land degradation, which are especially critical in arid regions. The research involved an engineering-geological analysis of soils using laboratory and computational methods. Evaluated parameters included humus content, mobile phosphorus, nitrogen, exchangeable bases, water retention, and resistance to erosion. Experimental results showed that vermicompost significantly improves soil structure and geotechnical stability. Potassium polyacrylamide enhances water retention, reducing the risk of deformation and settlement. Lime-sulfur broth strengthens surface horizons and reduces wind erosion, although its impact on mechanical properties requires further study. The proposed biostabilization methods effectively improve the geotechnical characteristics of weak soils, increasing their resistance to erosion and enhancing their suitability for engineering applications such as foundation stabilization, slope reinforcement, and land restoration. These technologies are especially relevant in arid climates, where soil degradation is widespread. The study's findings can be applied in geotechnical engineering, engineering geology, and sustainable agriculture to support environmentally responsible land use and the restoration of degraded areas.

The main reserves of fresh groundwater in South Kazakhstan are confined to aquifers of Quaternary, Neogene, Paleogene, Cretaceous deposits of Artesian basins. They play a major role in the water supply of the population with drinking water, especially large water consumers. Fractured water basins are characterized by significantly smaller reserves of fresh groundwater, but their widespread distribution in the region is of practical interest for the water supply of smaller water consumers. The anthropogenic impact on groundwater has become especially noticeable in the current century due to the development and intensification of industry and agriculture, the growth of large cities and the expansion of urbanized territories. Intensification of the anthropogenic load on the resource potential of groundwater and associated ecosystems leads to a progressive deterioration of ecological and hydrogeological conditions in South Kazakhstan. This is primarily due to the depletion of groundwater resources, the formation of depression craters and water retention zones, groundwater pollution, which significantly affects the natural environment and human habitat. These negative changes occur especially intensively in areas of mining, oil and gas production and chemical industry development, characterized by significant changes in the existing water exchange, which is caused by violations of the water balance in the subsurface caused by the drainage of mineral deposits during their extraction, the exploitation of groundwater for domestic and industrial water supply and drainage systems, and also presence of industrial and household untreated effluents. © 2022, National Academy of Sciences of the Republic of Kazakhstan. All rights reserved.