This study analyzes long-term changes in minimal streamflow in the Zhaiyk-Caspian Water Management Basin (WMB), Western Kazakhstan, under climate variability. Using extensive hydrometeorological datasets (monthly discharge and daily meteorological records) from 1940 to 2021, the research assesses trends in low-flow characteristics across 18 hydrological posts. The analysis distinguishes two climatic periods: climate stabilization (pre-1973) and climate change (1974–2021). The methodology integrates hydrological and statistical analyses, including minimal monthly discharges, low-flow durations, soil freezing depths, and thaw frequencies. Findings reveal a widespread increase in winter low flows—up to 5.2 times—due to reduced frost depths and more frequent thaw events, enhancing groundwater contributions. Conversely, summer-autumn flows declined in several rivers, with drying trends linked to rising air temperatures and precipitation deficits. This study offers a novel, regionally adapted methodology for characterizing minimal streamflow under climate change, providing critical insights for hydrological drought assessment and water resource planning in arid and semi-arid environments.

Electrospun fiber-based photocatalysts demonstrate significant potential in addressing global environmental and energy challenges, primarily due to their high specific surface areas and unique properties. This review examines recent advances in the application of these materials in photocatalytic processes, with a particular focus on water splitting and hydrogen production. The principles of the electrospun method are described in detail, along with the operating parameters, material characteristics, and environmental conditions that affect the fiber formation. Additionally, the review discusses the challenges, advantages, and future prospects of photocatalysts incorporating carbon materials, metals, semiconductors, and hybrid structures with improved performance. These materials have the potential to significantly improve the efficiency of hydrogen energy production, water purification, and CO2 recovery, highlighting their importance in engineering sciences. © 2024 by the authors.

Centrifugal pumps are extensively utilized across various industries, including water supply, agriculture, and energy, where they consume significant amounts of electricity. As demands for energy efficiency and reduced operating costs increase, enhancing pump efficiency has become crucial. This study focuses on optimizing the pump impeller geometry, which plays a vital role in minimizing energy losses. A hydraulic and hydrodynamic model was developed, alongside a parametric study based on numerical simulations (CFD), to analyze the influence of geometric parameters—specifically the angles and shapes of the blade’s inlet and outlet edges—on energy losses and hydraulic efficiency. The study utilized experimental data provided by the manufacturer for model verification. The results revealed that Ivanovsky’s method displayed deviations in the blade width at the leading edge and trailing edge of 25% and 43%, respectively, while Spiridonov’s method indicated deviations of 13% in the outer diameter (Formula presented.) and 27.5% in the blade width at the trailing edge. In contrast, the combined method proposed by the authors achieved high accuracy, with deviations under 9%. Additionally, parametric analysis identified two key parameters affecting the pump efficiency: the angle of the trailing edge and its shape. These findings underscore the necessity of optimizing the blade geometry to enhance the performance and energy efficiency of centrifugal pumps. © 2024 by the authors.

This paper is devoted to experiments on testing of the Sn-Li capillary porous system (CPS) under conditions of deuterium plasma irradiation, carried out at a plasma-beam installation (PBI). As a metal CPS matrix, molybdenum mesh was used. The paper presents a detailed description of the development of technology and procedure for the fabrication of the investigated sample, intended for plasma testing, as well as experiments on irradiation of Sn-Li CPS with deuterium plasma. As a result of the experiments performed, the dependences of the temperature of the investigated sample on the energy of the plasma contacting with the CPS, time dependence of the gas phase composition in the PBI chamber during irradiation of Sn-Li CPS with deuterium plasma, optical spectra depending on the temperature were obtained. Post-experimental material science studies with a sample of Sn-Li CPS were also performed and the results of microstructure, thermal and X-ray phase analysis were obtained. Analysis of the experimental data obtained showed that the energy of deuterium plasma precipitated on the Sn-Li alloy is re-emitted into the energy of optical radiation on the evaporating neutral atoms of lithium and tin. A complete evaporation of the alloy from CPS, during interacting with deuterium plasma, leads to partial destruction of the metal matrix of molybdenum. © 2023 Elsevier B.V.

Ceria-based H2O/CO2-splitting solar-driven thermochemical cycle produces hydrogen or syngas. Thermal optimization of solar thermochemical reactor (STCR) improves the solar-to-fuel conversion efficiency. This research presents two conceptual designs and thermal modelling of RPC-ceria-based STCR cavities to attain the optimal operating conditions for CeO2 reduction step. Presented hybrid geometries consisting of cylindrical–hemispherical and conical frustum–hemispherical structures. The focal point was positioned at x = 0, -10 mm, and -20 mm from the aperture to examine the flux distribution in both solar reactor configurations. Case-1 with 2 milliradian S.E (slope error) yields a 27% greater solar flux than case-1 with 4 milliradians S.E, despite the 4 milliradian S.E produces an elevated temperature in the reactor cavity. The mean temperature in the reactive porous region was most significant for case-2 (x = -10 mm) with 4 mrad S.E for model-2, reaching 1966 K and 2008 K radially and axially, respectively. In case-2 (x = -10 mm) for 4 mrad S.E, model-1 attained 1720 K. The efficiency analysis shows that the highest conversion efficiency value was obtained to be 7.95% for case-1 with 4 milliradian S.E. © 2023 The Author(s)

Oil spills on land pose significant environmental hazards, impacting ecosystems and human health. Effective detection and monitoring of these spills are critical for timely response efforts. This paper presents for the first time a ground truth dataset for onshore oil spill detection developed using Landsat imagery. The ground truth was implemented using aerial data. To demonstrate the utility of this dataset, we evaluated several state-of-the-art deep learning models, including DeepLabV3+, UNet, PSP-Net, DeepLabV3 and Mask2Former. Our experiments revealed significant insights into the models’ capabilities and limitations. Mask2Former and DeepLabV3+, in particular, showed the highest performance metrics. On the validation data, Mask2Former achieved an intersection over Union (IoU) of 72.69% and a F-score coefficient of 84.18%, while DeepLabV3+ achieved an IoU of 67.6% and a F-score coefficient of 80.67%. These results demonstrate the effectiveness of our dataset as a crucial tool for enhancing oil spill detection methodologies and advancing the application of artificial intelligence in ecological preservation and disaster management. ©The Author(s) 2024.

Қазіргі заманғы операторлар қолданатын өлшеу техникасы тек стандартқа сәйкестікті (бірінші кезекте халықаралық стандарттар) ғана тексеріп қоймай, сонымен қатар желіден өтетін үрдістерді оқыту үшін де қолданылады. Жоғары жіберу қабілеттілігі бар сандық жүйелерге өту, т.б. байланыс жүйелерінің қиындықтары объективті түрде өсіп отырады. Сонымен қатар, телекоммуникациялық жүйелердегі өлшеулердің таратылуы мен зерттелуіне нақты мысалдар беріліп, олардың әдістемелері, интеллектуалды желі түйіндерінің ішкі диагностикасының даму жүйесі, сондай-ақ қазіргі заманғы өлшеу техникаларын қолдану да толығымен қарастырылған. Оқу құралы өлшеу техникасы жүйесін өңдеушілерге, сонымен қатар: «радиотехника», «электроника және телекоммуникация», «ақпараттық жүйелер», «есептеу техникасы және программалық қамтамасыз ету», т.б. мамандық студенттері мен магистранттарына пайдалы болып есептеледі.

Layers of TiO2 nanotubes formed by the anodization process represent an area of active research in the context of innovative energy conversion and storage systems. Titanium nanotubes (TNTs) have attracted attention because of their unique properties, especially their high surface-to-volume ratio, which makes them a desirable material for various technological applications. The anodization method is widely used to produce TNTs because of its simplicity and relative cheapness; the method enables precise control over the thickness of TiO2 nanotubes. Anodization can also be used to create decorative and colored coatings on titanium nanotubes. In this study, a combined structure including anodic TiO2 nanotubes and SrTiO3 particles was fabricated using chemical synthesis techniques. TiO2 nanotubes were prepared by anodizing them in ethylene glycol containing NH4F and H2O while applying a voltage of 30 volts. An anode nanotube array heat-treated at 450 °C was then placed in an autoclave filled with dilute SrTiO3 solution. Scanning electron microscopy (SEM) analysis showed that the TNTs were characterized by clear and open tube ends, with an average outer diameter of 1.01 μm and an inner diameter of 69 nm, and their length is 133 nm. The results confirm the successful formation of a structure that can be potentially applied in a variety of applications, including hydrogen production by the photocatalytic decomposition of water under sunlight. © 2024 by the authors.

Wind power in Kazakhstan, following the global trend, continues to develop and there is an increase in the number of RES power plants. The development of wind energy involves the creation of large-sized and high-power installations. The rotors of wind turbines experience heavy loads on their design. Thus, the actual task and problem for the wind energy park of Kazakhstan is to reduce the load on the structure by regulating it during wind gusts. The use of a control system for the rotation of the blades makes it possible to significantly reduce the load on the structure. However, due to the non- linearity of the process and the difficulty of accurately measuring the wind speed, the blade turning control system must be designed with great care. This paper presents the development of a lever mechanical system for controlling the blades of a wind turbine, which makes it possible to secure the operation of a wind generator. The purpose of the study is to develop a 3D model of a lever control system and create an automatic control system for it. A three-dimensional study of the rotor in various states of the rotor was carried out. This dynamic computer model is proof of the functionality of the communication system. The transfer function of the entire control system is also determined and, based on experimental data, a mathematical model of an experimental laboratory sample is developed. This installation will optimize the operation of a vertical axis wind generator by creating a wind flow control system for further converting the wind flow into electrical energy. © 2022 IEEE.

Оқу құралы мамандардың квалификациялық сипаттамасының талабына сай, Мемлекеттік стандарттар мен ұйымдардың педагогика-психологиялық негізіне орай лекциялық, практикалық, зертханалық сабақтар жүргізуге арнап құрастырылған. Оқу құралында жоғары математиканың бір саласы, тиімділеу әдістерінің компьютерге программалауға ыңғайландырылған алгоритмдері, жан-жақты талданған мысалдар, жеке орындауға арналған есептер берілген. Ол студенттерді оқу процесінде өз бетімен жұмыс істеуге және тақырыпты меңгеруге, білім деңгейін қалыптастыруға бағыттайды. Сондай-ақ, олардың өзара байланысын нығайтады. Оқу құралы "Тиімділеу әдістері және операцияларды зерттеу пәні бойынша" пәнінің 3 кредит көлемінде жазылған жұмыс бағдарламасына сәйкес жазылған. Ұсынылып отырған оқу құралын оқу жоспарында "Операцияларды зерттеу", "Математикалық модельдеу", "Тиімділеу әдістері" пәндері бар әртүрлі оқу формасындағы студенттердің пайдалануына болады.