Along with the evolution of renewable energy technologies and some other systems such as electric vehicle, demands for batteries as storage unit has increased. Keeping the temperature of batteries in a specific range is necessary to have reliable performance and prevent degradation. In regard to the enhanced thermophysical specifications compared with pure heat transfer fluids, nanofluids would be attractive alternatives for them in thermal management of batteries. The purpose of this article is to identify the impact of using nanofluids for thermal management of batteries as heat transfer fluid with improved properties and evaluate the impactful factors in their cooling performance both as direct coolant or operating fluid of heat pipes as cooling mediums. In this regard, this article reviews the studies implemented on the thermal management of batteries by use of nanofluids. Reduction in maximum temperature of battery packs and temperature difference, due to elevation of heart transfer as a consequence of increment in the thermal conductivity, are the most remarkable outcome of using nanofluids for battery thermal management. Although nanofluids could be advantageous in term of heat transfer intensification, increment in the pressure drop can be one of the disadvantages in conditions of using liquid flow. In cases of using nanofluidic thermal mediums like heat pipes, the enhancement in the cooling performance can be attributed to some other factors, e.g. increase of nucleation sites for promotion of two-phase heat transfer, as well as thermal conductivity elevation. Concentration of the nanomaterials, operating condi tions, specifications of the solid phase are among the most significant items in the effectiveness of the cooling techniques with nanofluids. In design of nanofluidic thermal management units of batteries, the mentioned influential factors must be taken into account to reach the optimal performance.

This paper explores the potential application of a 3-UPU manipulator as a design for a metal 3D printer. To determine the working area of the 3-UPU manipulator, its inverse kinematics were investigated. Using the Denavit-Hartenberg method, the required lengths of the manipulator’s prismatic pairs were analytically calculated based on the coordinate system transformation matrices. The obtained results were verified by numerical methods in MATLAB program and the correctness of analytical solutions was confirmed. The study showed that the working area of the 3-UPU manipulator is 800x800x600 mm, which is large enough for metal 3D printers. This work area gives you the ability to print from small parts to large parts as well as body parts. The precise positioning and dexterity of the 3-point manipulator ensures sufficient precision in part production. This working area makes it possible to print from small parts to large parts as well as body parts. The positioning accuracy and dexterity of the 3UPU manipulator provides sufficient accuracy in part production. This accuracy of part fabrication reduces the post-processing time of parts by machining, resulting in less material consumption for chips and wear of cutting tools. This research work can provide a scientific basis to enable the 3-UPU arm to be used in metal 3D printers. Future research following this work is planned to explore issues such as improving the dynamic model of the manipulator and increasing its efficiency by optimizing control algorithms

Бұл ғылыми-зерттеу жұмысының өзектілігі автомобильдердегі форсирленген қозғалтқыштарды пайдалану тиімділігін арттыру және оларды жөндеуге кететін ағымдағы шығындарды азайту үшін қосымша мүмкіндіктерді іздеу қажеттілігімен негізделеді. Зерттеу мақсаты — қозғалтқыштағы май деңгейінің майдың ескіру процестеріне және дизельді қозғалтқыштың техникалық жай-күйінің өзгеруіне әсер етуінің жалпы принциптері мен заңдылықтарын бағалау. Зерттеу барысында автомобиль қозғалтқышын пайдалану кезінде мотор майы параметрлерінің өзгеру сипатына эксперименттік бағалау жүргізілді. Алынған нәтижелер әр 2000 км сайын май құюды қарастыратын, қазіргі уақытта қабылданған автомобиль дизельді қозғалтқышының картеріне май құю жиілігін қайта қарау қажеттілігін көрсетеді. Себебі, бұл жағдайда қозғалтқышты пайдалануға кететін меншікті шығындар жоғары болғандықтан, экономикалық тұрғыдан тиімсіз. Нәтижелердің практикалық маңыздылығы оларды автокөлік техникасына қызмет көрсету кезінде, сондай-ақ күрделі жөндеу немесе дизельді қозғалтқыштарды форсирлеу қажет болған жағдайда, майлау жүйесіндегі май көлемін өзгерту мүмкіндігінде жатыр.

Microchannel heat sinks (MCHSs) are effective and compact thermal management devices that are broadly developed in recent years. Performance of these equipment is impacted by a variety of the factors that have been investigated and evalu ated by the scholars and researches. Use of coolant with improved thermal properties can elevate heat transfer rate and consequently the thermal performance. One of the attractive techniques for improvement of convective heat transfer is use of nanofluids, with higher thermal conductivity in comparison with the conventional heat transfer fluid, as the coolant. The aim of the current article is to comprehensively review the applications of the hybrid nanofluids, containing more than single nanomaterial in the base fluid, in the MCHSs. Findings of the research works on the use of these nanofluids in MCHSs have revealed considerable potential for elevation in heat transfer rate. Several factors impact the modification of heat transfer in MCHSs with hybrid nanofluids including the characteristics of the coolant, configuration of the system and operating conditions. As well as heat transfer, other factors such as the pressure drop and entropy generation would be impacted due to the existence of the hybrid nanomaterials in the working fluid. Some recommendations are presented in this article for the forthcoming researches in order to further enhance the heat transfer and modify the characteristics of these systems.

This paper presents the results of a thermodynamic analysis of equilibrium phase diagrams for systems relevant to the ternary-melt Ti-10V-2Fe-3Al alloy, along with calculations of thermodynamic parameters and a staged thermodynamic prediction of the technological conditions for vacuum arc remelting (VAR). Three remelting stages are justi􀂿ed thermodynamically: the 􀂿rst melt removes coarse Fe, V, and Al oxides; the second melt breaks down most FeTi/Fe₂Ti intermetallics and transfers part of the titanates into slag; the third melt brings the system close to equilibrium, minimizing oxide and intermetallic inclusions. Practical recommendations were developed based on the thermodynamic analysis, including the required vacuum level (pO₂ ≤ 10⁻²⁰–10⁻²²), control of O, N, and H impurities, requirements for alloying additions, conditions for ternary remelting, and β-homogenization

The properties of phosphate coatings formed on St3 carbon steel were investigated using calcium–manganese–phosphate solutions derived from Zhayrem ore beneficiation wastes and compared with conventional Mazhef salt solutions. Protective performance was evaluated using the drop method, gravimetric tests, and electrochemical techniques. Coatings obtained from the waste-derived solution at 85 °C for 60 minutes exhibited a protective capacity 1.5 times higher than those formed in Mazhef solutions. Electrochemical measurements confirmed this result, with corrosion current densities of 0.974 µA/cm2 for waste-derived coatings, compared to 1.623 µA/cm2 for Mazhef coatings and 2.337 µA/cm2 for uncoated steel. Gravimetric tests showed a lower mass loss over 8 days of immersion (0.0024 g vs. 0.0058 g). SEM and EDS analyses revealed that waste-derived coatings formed dense Ca–Fe–Mn–P layers with a thickness of ~11.1 µm, while Mazhef coatings were thinner (2.96–6.23 µm) and more porous. These findings demonstrate that manganese ore beneficiation wastes are an effective and sustainable source of phosphating agents for producing corrosion-resistant coatings on carbon steel.

The purpose of this article is to consider the main types of failures of load-bearing parts of traction rolling stock, which have a significant impact on the operational reliability and safety of railway transport. In the bearing components of the mechanical part of locomotives, both gradual and sudden failures may occur. The analysis of the causes of failures, fatigue failures, wear, corrosion damage, and manufacturing defects has been performed. Gradual failures arise due to the accumulation of fatigue damage. The methods of increasing the life of the bearing elements and improving the design are proposed. Sudden failures are defined as those associated with a reduction in the safety margin of long-term (static) or impact strength below the permissible value. According to these studies, the probability of a sudden failure is determined as the probability that the random value of the applied static stress exceeds the random value of some characteristic of the material's strength, σR, which refers to the yield strength or tensile strength, σb. The results of this study can be used in the development of technical measures for the maintenance and repair of locomotives.

В данной статье представлена математическая модель адаптивного управления гибридного кривошипного пресса с обратной связью. Рассмотрена динамическая модель пресса, включающая механическую и электрическую составляющие, а также учтены изменения параметров системы в реальном времени. Предложен адаптивный закон управления, основанный на методах идентификации параметров и корректировки управляющего воздействием в зависимости от текущего состояния пресса. Проведен анализ устойчивости системы и показаны преимущества предложенного подхода перед классическими методами управления. Статье рассматриваются методы синтеза систем управления при решении задач слежения для многомерных стохастических моделей объектов, функционирующих в условиях неполной информации о состоянии объекта и его параметров. При этом проектирование систем управления осуществляется путем постепенного добавления и усложнения используемых методов и алгоритмов: от оптимального управления для детерминированных моделей, до адаптивных следящих систем для стохастических моделей при неполном измерении с ошибками. Основным методом исследования является имитационное моделирование Результаты моделирования подтверждают эффективность разработанной системы управления при изменяющихся нагрузках и внешних воздействиях. Предложенная система демонстрирует высокую устойчивость и способность адаптироваться к широкому спектру эксплуатационных условий. Проведен анализ устойчивости системы и показаны преимущества предложенного подхода перед классическими методами управления.

The article is a review article devoted to the devices and methods of their use for the experimental study of the stress-strain state of the earth bed of road and railway embankments, approach embankments to bridges, and transport interchanges. Today, an important task in the construction of embankments is the determination of the expected settlement. To measure the stresses in the soil mass of the roadbed, sensors based on strain gauges (Messdozes) are used. The authors consider several types of messdozes according to the ‘classical scheme’, analyze the revealed disadvantages of different designs during laboratory and field tests, and describe the ways of their elimination. The advantages of the modernized scheme of messdozes are described, and the calibration of the modernized sensors (Messdozes) is considered. Modernized sensors have been tested by students of the scientific circle ‘Transport constructions’ under the direction of Associate Professor Bondar I.S. during a series of laboratory experiments carried out on the basis of the testing laboratory ‘Testing of track and artificial constructions’ of ALT University named after Mukhamedjan Tynyshpaev, Almaty.

This paper presents the results of producing a triple-remelted Ti-10V-2Fe-3Al alloy. The results of SEM–EDS analysis of the alloy are reported, and the structure of the Ti-10-2-3 alloy along the height of an industrial electrode is deter-mined. For the first time, results of a direct comparison between the morphology of the α/β phases and the local chemical com-position in three characteristic zones of a 4.5 t electrode, “top”, “middle 1”, “middle 2”, and “bottom”, are obtained based on comprehensive SEM–EDS analysis. It is established that, with respect to the main alloying elements (Ti, Al, V), the ingot is fully chemically homogenized along its height, and the VAR (vacuum arc remelting) regime ensures an acceptable level of macrosegregation. It is shown that the concentrations of (Ti, Al, V), the principal alloying elements in Ti-10V-2Fe-3Al, do not change significantly between samples. SEM–EDS results indicate that the scatter in elemental concentrations is ≤1-1.5%, which is considered an indicator of high-quality VAR processing; this level of scatter implies minimal differences in elemental concentrations: Al variations are within ±0.5-1.0%, V variations are within ±0.5-1.0%, and Ti maintains a stable fraction of approximately ~83-86%. Morphological studies reveal that the α/β structure is formed uniformly, without pronounced colum-nar segregation. The results of the direct comparison of α/β-phase morphologies enabled the development of a quality-control methodology for electrodes based on SEM–EDS profiles.