Karaganda State Technical University

This article examines the effect of working gas temperature during gas-dynamic spraying (GDS) on residual stresses in coatings made of CRO ceramics and NiAlSiCr metal composites. GDS is a promising technology for applying protective and restorative coatings in mechanical engineering, preventing component overheating (the substrate temperature typically does not exceed 100-150 °C). The method involves the solid-phase bonding of powder particles, accelerated to supersonic speeds, with the component surface due to their plastic deformation upon impact. The working gas is typically heated to temperatures between 300°C and 700°C. Experiments were conducted using a DIMET 405 setup on St3 steel samples at three gas stagnation temperature settings: 200°C, 300°C, and 400°C. Residual stresses were measured using an IKN-3M-129 stress concentration meter. It was found that increasing the working gas temperature from 200°C to 400°C sharply reduced compressive residual stresses (to -121.75 MPa for NiAlSiCr and -81.125 MPa for CRO at 200°C), followed by a transition to low tensile stresses (to +3.5 MPa for CRO). This is explained by the fact that higher temperatures increase particle plasticity, facilitating their deformation and adhesion. A spraying temperature of 400°C was found to be optimal for minimizing residual stresses, which is important for ensuring the stability and durability of the coating.

The article examines the problems of rock mass preparation during stripping operations in open-pit mines in conditions of waterlogging. It provides an overview of the basin’s geological characteristics, regulatory and methodological documents for drilling and blasting operations, and actual consumption rates of explosives. The impact of waterlogging on slope stability, equipment productivity, and the economics of stripping operations is analyzed. Three groups of measures to reduce waterlogging are described : general quarry, local, and process; surface, underground, and combined drainage methods are considered. Particular attention is paid to preliminary contour blasting as a local method for creating drainage zones. A conclusion is drawn regarding the need for systematic research into the conditions for applying local and quarry measures to improve the efficiency and safety of blasting operations in waterlogged massifs Тау жыныстарының сулануы жағдайында аршу жұмыстарын жүргізу кезінде тау-кен массасын дайындау мәселелері қарастырылды. Бассейннің геологиялық сипаттамасы, бұрғылау-жару жұмыстары бойынша нормативтік құжаттарға және жарылғыш заттарды тұтынудың нақты көрсеткіштеріне шолу берілген. Суланудың беткейлердің тұрақтылығына, техниканың өнімділігіне және аршу жұмыстарының экономикасына әсері талданды. Су тасқынын азайту жөніндегі іс-шаралардың үш тобы сипатталған: жалпы мансаптық, жергілікті және процестік; жер үсті, жерасты және аралас құрғату әдістері қарастырылған. Дренаждық аймақтарды құрудың жергілікті әдісі ретінде алдын-ала контурлық жарылысқа назар аударылды, су басқан массивтердегі жарылыс жұмыстарының тиімділігі мен қауіпсіздігін арттыру үшін жергілікті және мансаптық шараларды қолдану жағдайларын зерттеу қажеттілігі туралы қорытынды жасалды Рассмотрены проблемы подготовки горной массы при ведении вскрышных работ на разрезах в условиях обводненности пород. Приведен обзор геологической характеристики бассейна, нормативно-методических документов по буровзрывным работам и фактических показателей расхода взрывчатых веществ. Проанализировано влияние обводненности на устойчивость откосов, производительность техники и экономику вскрышных работ. Описаны три группы мероприятий по снижению обводненности: общекарьерные, локальные и процессные; рассмотрены поверхностный, подземный и комбинированный способы осушения. Особое внимание уделено предварительному контурному взрыванию как локальному методу создания дренажных зон, сделан вывод о необходимости системных исследований условий применения локальных и карьерных мероприятий для повышения эффективности и безопасности взрывных работ в обводненных массивах

This study considers a multistage thermoacoustic engine with an external heat supply, used to convert low-grade heat from solar and geothermal sources into electrical energy. The study [k of improving the efficiency of thermoacoustic engines using low-grade heat sources remains unresolved because of high self-starting temperatures and significant heat loss. This study examines an approach based on the design of a multistage thermoacoustic engine with an external heat supply, which reduces the starting temperature and improves efficiency. To achieve this goal, mathematical modeling was performed in the DeltaEC environment using a linear approximation of Rott equations; a laboratory prototype of an eight-stage engine was designed. The results showed that at a heater temperature of 105°C and an average pressure of 2 bar, an acoustic oscillation frequency of 64 Hz and an electrical power of up to 80 W are achieved with an efficiency of approximately 12%. Distinctive features of the proposed structure include optimized stage and resonator geometry, the use of a traveling acoustic wave, as well as the ability to operate at low heating temperatures, which distinguishes it from existing analogs. It has been established that increasing the stage diameter to an optimal ratio of 10:1 relative to the resonator, improving thermal insulation, and increasing pressure to 8 bar could increase efficiency by up to 40%. The practical significance of this work is its potential for implementing the designed engine in autonomous power supply systems in rural and remote areas of the Republic of Kazakhstan where electricity costs are traditionally higher and fuel delivery is difficult. The results confirm the feasibility of using thermoacoustic technologies for sustainable and environmentally friendly energy supply

The innovative potential of companies is a pivotal driver of both firm-level competitiveness and broader economic transformation. This study quantitatively and qualitatively assesses how innovation—viewed as a core component of intellectual capital—affects the commercial success of companies across Eastern Europe, the Caucasus, and Central Asia (EECCA) compared to adjacent European markets. A regression analysis on panel data reveals that intellectual capital innovation explains 54% of the variation in inclusive growth among firms oriented toward sustainable development. Specifically, Human Capital Innovation exhibits the strongest positive effect (β = 0.438, p < 0.001), followed by Relational Capital Innovation (β = 0.319, p < 0.001), and Structural Capital Innovation (β = 0.217, p = 0.0004). Firm size also positively correlates with growth (β = 0.124, p = 0.006), confirming scale effects. Knowledge-intensive companies in the Caucasus and Central Asia remain at an early development stage, whereas firms in Eastern Europe demonstrate innovation efficiency comparable to more advanced European markets. A qualitative analysis further substantiates the significant correlations between innovation, intellectual capital, human resource management, and firm success. The findings support the practical use of innovation management and intellectual capital development strategies to enhance competitiveness, particularly in emerging markets undergoing industrial transformation.

This study investigates the thermo-mechanical behaviour of titanium alloys during milling with the aim of developing a predictive approach for reducing thermal loading and improving process stability. A three-dimensional finite element model was constructed in Kompas-3D and simulated in ANSYS Workbench using the Johnson–Cook constitutive and damage model. To systematically analyse the effects of process variables, a five-level experimental design was employed, in which cutting depth, feed rate, and spindle speed were varied. The results of 25 simulation runs were processed in ANETR-5 software to establish a regression model linking cutting parameters with the workpiece surface temperature. The findings revealed that heat accumulation is strongly localised at the tool–chip interface, while subsurface temperature stabilises near 101.9 °C. Cutting forces were observed to fluctuate in all coordinate directions, reflecting the intermittent engagement of milling teeth and providing insight into potential process instability. The regression model demonstrated high adequacy with SD = 28.76%, R = 0.948, and F = 12.093. Optimisation indicated that the combination of cutting depth t = 1 mm, feed rate S = 4500 mm/min, and spindle speed n = 4162 rpm yields the most favourable thermal response. The approach provides a reliable basis for optimising titanium machining, improving tool life, surface integrity, and overall cost efficiency.

This article describes a new approach to optimizing the parameters of mechanical hole machining, which solves the problem of compromise between various criteria, such as machining time, tool durability, and surface quality. Traditional optimization methods, as shown in the study, usually focus on a single parameter, which inevitably leads to deterioration in others. For example, increasing the cutting speed to reduce machining time causes rapid tool wear, while reducing parameters to improve surface quality significantly increases time and production costs. To overcome these shortcomings, a methodology based on weighted multi-criteria analysis was developed. The methodology includes several stages: data collection, formation of objective functions, definition of constraints, normalization of criteria, and selection of an optimization method. A key element is the use of weighting coefficients, which allow the methodology to be adapted to specific production priorities. The study was conducted using a specific example of optimizing hole drilling in 45 steel. Weighting coefficients were set, with the greatest weight given to processing time (0.5), followed by roughness (0.3) and tool resistance (0.2). As a result, the following parameters were recognized as optimal: cutting speed vc = 22 m/min and feed fz = 0.2 mm/rev. With these values, the processing time was reduced from 37.9 to 28.7 seconds, while tool durability decreased from 275.2 to 176.4 μm. This clearly demonstrates that the method has found a compromise solution that allows reducing the time without critically compromising tool durability

IntroductionThis clinical report describes the management of a 32-year-old patient with a long-standing history of drug-resistant epilepsy. It uniquely illustrates how stereoelectroencephalography (SEEG) played a significant role in the presurgical evaluation of a multifocal epileptic disorder which, despite a long history of no changes on MRI, was ultimately found to be associated with bilateral hippocampal sclerosis. This is one of the first documented cases of SEEG application in Kazakhstan, where the method was introduced in 2024.Clinical presentation and diagnostic findingsThe patient suffered from debilitating seizures (4–6 times/week, often in series of 3-4/day) refractory to combined antiepileptic therapy. Scalp EEG revealed the first originating from the right frontotemporal leads with subsequent diffuse, predominantly right-sided, propagation. The second seizure, however, showed onset from the left temporal leads; notably, only left-onset seizures culminated in bilateral synchronization. Financial constraints precluding PET-CT and the diagnostic ambiguity of routine methods necessitated invasive SEEG.SEEG results and therapeutic strategySEEG monitoring unequivocally identified three independent epileptogenic foci: in the right hippocampus, left hippocampus, and left orbitofrontal region. Such multifocal pathology significantly reduces the likelihood of successful focal resection. Despite this inherent complexity, a crucial clinical outcome was achieved: the patient has remained completely seizure-free for 7 months following the ANT-DBS procedure.ConclusionThis report underscores the critical role of SEEG in the precise localization and characterization of complex, multifocal epileptogenic networks, often elusive to non-invasive modalities. It convincingly demonstrates that a comprehensive invasive approach can lead to successful seizure control even in cases previously considered inoperable. It also reflects the challenges and advancements in developing high-tech epileptological care in regions where advanced methods like SEEG have only recently been introduced.

It is known that most casting molds are made using a binder. To exhibit its effect, the binder additive must initially be in the liquid state, then form a film on the surface of the solid phase, develop a cuff around the contact points between the grains, and solidify, thereby turning the bulk mixture into a monolithic medium. Sand-resin mixtures meet all these requirements. Casting molds made from such mixtures enable the production of high-quality castings from a wide range of alloys. However, their widespread industrial application is hindered by the relatively high cost of the binder, pulverbakelite. Therefore, research aimed at improving the manufacturing processes of durable sand-resin molds while reducing the content in the mixture, without compromising other parameters, is highly relevant.

This article provides a comprehensive examination of the theoretical foundations of the dystopian genre and its manifestation in Kazakh literature. It first analyzes the genre-specific characteristics, purpose, and thematic essence of dystopia, such as the loss of individual freedom, totalitarian control, systemic injustice, and estrangement from truth. Canonical works like George Orwell's 1984 and Yevgeny Zamyatin's We are explored as key references, offering a comparative basis for assessing how dystopian themes have evolved within the Kazakh literary context. The central focus of the study is Akhan Tokish's novel Mangurtstan, interpreted as a dystopian vision of Kazakhstan's socio-political trajectory in the 21st century. The article investigates the novel's linguistic hybridity, ideological manipulation of national consciousness, and the mechanisms of authoritarian control within economic and institutional systems. These elements are compared with global dystopian models while emphasizing their uniquely national dimensions. A significant component of the analysis is dedicated to the linguistic features of dystopia in Mangurtstan. The novel uses semantic inversion, parody, and bureaucratic language to depict the erosion of meaning, identity, and communication under oppressive regimes. Sarcasm and hybridized multilingual expressions serve not only as stylistic devices but as tools of sharp cultural critique. The study aims to reveal the aesthetic and philosophical importance of dystopian narratives in Kazakh literature and their role in reflecting historical memory and cultural identity. Through descriptive, comparative, and textual analysis, the research contributes to the broader integration of dystopian studies into Kazakh literary scholarship.

A clinical case of a child with a rare mitochondrial disease, Kearns-Sayre syndrome, who had a pacemaker implanted due to the development of complete atrioventricular block, is presented for the first time in the Republic of Kazakhstan. The issues of complex diagnostics and management tactics are discussed.