The object of consideration is seismic design, and the subject of the study is the determination of the reduction coefficient. One of the important problems of earthquake-resistant design is to determine the effect of low-cycle fatigue of reinforced concrete on the reduction coefficient and determine its optimal value. This problem is not disclosed and is not specifically taken into account in the standards for earthquake engineering when determining the maximum bearing capacity of types of structures due to the lack of study of the issue. To solve the problem, a series of experimental studies were carried out on low-cycle fatigue of reinforced concrete bending elements and frame units. The range of results of the reduction coefficient values and the degree of influence of monocyclic fatigue on the properties of the reduction coefficient are obtained. A feature and characteristic of the results obtained is that the reduction coefficient Rμ depends on the nature of the hysteresis deformation pattern and the plastic life of structural elements estimated by the plasticity coefficient μ, which is significantly influenced by low-cycle fatigue manifested at peak accelerations of strong seismic impacts. The above test algorithm, the feature and characteristics of the results obtained made it possible to solve the problem under study. The results obtained are accepted for practical use in the action of seismic loads: on the calculation of strength taking into account new low-cycle coefficients, reduction coefficients for determining the spectra of design reactions and seismic loads, taking into account energy absorption. New reduction coefficients are proposed for determining the spectra of calculated reactions and seismic loads

This study presents an integrative investigation of four rare and threatened plant species—Taraxacum kok-saghyz L.E. Rodin, Astragalus rubtzovii Boriss., Schmalhausenia nidulans (Regel) Petr., and Rheum wittrockii Lundstr.—native to the Ile Alatau and Ketmen ridges of the Northern Tian Shan in Kazakhstan. Combining chloroplast genome sequencing, geobotanical surveys, and anatomical and population structure analyses, we aimed to assess the ecological adaptation, genetic distinctiveness, and conservation status of these species. Field surveys revealed that population structures varied across species, with T. kok-saghyz and S. nidulans dominated by mature vegetative and generative individuals, while A. rubtzovii and R. wittrockii exhibited stable age spectra marked by reproductive maturity and ongoing recruitment. Chloroplast genome assemblies revealed characteristic patterns of plastid evolution, including structural conservation in S. nidulans and R. wittrockii, and a reduced inverted repeat region in A. rubtzovii, consistent with its placement in the IR-lacking clade of Fabaceae. Morphological and anatomical traits reflected habitat-specific adaptations such as tomentose surfaces, thickened epidermis, and efficient vascular systems. Despite these adaptations, anthropogenic pressures including overgrazing and habitat degradation pose significant risks to population viability. Our findings underscore the need for targeted conservation measures, continuous monitoring, and habitat management to ensure the long-term survival of these ecologically and genetically valuable endemic species. © 2025 by the authors.

Proton exchange membranes (PEMs) play a critical role in various energy conversion devices, such as fuel cells. Developing advanced PEMs with improved hydronium ion transportation and chemical stability is essential for enhancing the performance and durability of these devices. In this research project, we focus on the development and molecular modeling study of a novel composite material based on poly(acrylic acid) and graphene oxide for application as a high-performance proton exchange membrane. The need for better PEMs has led us to explore the potential of combining poly(acrylic acid) and graphene oxide, as both materials offer unique advantages in terms of proton conductivity and mechanical strength. Our goal is to investigate how these two components interact and synergize to enhance the overall performance of the PEM, particularly in challenging operating conditions. To achieve this, classical all-atom Molecular Dynamics (MD) simulations using Gromacs software were employed. The simulations allowed us to study the formation mechanism of the poly(acrylic acid) and graphene oxide composite material and its application in facilitating hydronium ion transportation within the PEM. Our simulation results revealed fascinating insights into the composite material's behavior. Notably, we observed the emergence of new interactions between poly(acrylate) oligomers and graphene oxide layers, evident from the analysis of interaction energy values. These interactions contribute to the material's enhanced transport properties, making it promising for PEM applications. Moreover, we assessed the mobility of hydronium ions in the graphene oxide and polyacrylate nanocomposite-based PEM and found it comparable to the mobility in traditional poly(acrylate)-based PEMs. This indicates that the introduction of graphene oxide provide compatible proton transport efficiency and renders the composite suitable for practical application in PEM devices. In conclusion, our study demonstrates the potential of the poly(acrylic acid) and graphene oxide composite as a high-performance proton exchange membrane.

Due to its relatively low cost, availability, safety, low environmental impact, and versatility, nitrogen emerges as a promising candidate for enhanced oil recovery. This article provides an overview of nitrogen injection applications within reservoirs, encompassing both miscible and immiscible conditions. Additionally, this work reviews unconventional nitrogen-based enhanced oil recovery methodologies, including the utilization of foam-assisted nitrogen and cold nitrogen injection. To adapt miscible injection for reservoirs characterized by lower pressure, the combination of nitrogen with hydrocarbon gasses or CO2 presents a viable strategy. Notably, both miscible and immiscible nitrogen injection techniques demonstrate the potential to recover approximately 20 % of residual oil saturation. However, under conditions of high water cut, water alternating nitrogen injection surpasses regular immiscible nitrogen injection in terms of oil recovery. In the context of fractured rocks, foam-assisted water alternating nitrogen injection yields a 15 % higher oil recovery compared to conventional water flooding approaches. Intriguingly, nitrogen-based foams have been effectively deployed in field conditions to enhance the recovery of 920 cp oil from heterogeneous reservoirs, resulting in a remarkable up to 2.6-fold increase in oil flow rate. These compelling outcomes instigate a comparative investigation of the method's efficacy against the conventional chemical flooding technique. Furthermore, nitrogen exhibits remarkable potential for oil recovery from ultra-low permeability (198 nD) rocks, owing to its low molecular weight that facilitates penetration even into very small pores. Moreover, the injection of cold nitrogen (–26 °C) induces a substantial enlargement of fractures in low permeability rocks, accentuating its efficacy in this context.

This paper presents a comprehensive approach to forecast solar power generation in the Kazakhstani region, leveraging historical and weather data. The main challenge with solar power lies in its dependency on weather conditions, which significantly impacts day-ahead output planning and grid operations. To address this, we have employed advanced timeseries forecasting models like ARIMA, Facebook Prophet, and XGBoost to predict the power output for the next day. By utilizing the real data from two solar plants located in Kazakhstan and analyzing region's historical weather patterns, our proposed model were carefully validated with walk-forward model validation approach. Obtained results highlight superior performance of XGBoost model, outperforming plant dispatcher's predictions and demonstrate the potential of utilizing machine learning in enhancing the reliability of solar power forecasts. This research provides practical insights for both academics and practitioners, including grid managers and plant dispatchers, aiming to optimize solar power integration and reliable operation of the power grid.

Groundwater is becoming increasingly important as surface water is decreasing and becoming more and more polluted. In particular, rural areas in the arid region of Central Asia face problems with both water quantity and quality. In view of this, we investigated the drinking water quality in the Maysky district in the Pavlodar region, Kazakhstan. The organoleptic properties, together with microbiological indicators, as well as organic and inorganic substances of drinking water before and after treatment, and tap water were studied and compared to recommended levels. The bacteriological indicators of the drinking water, especially, showed that the water represents health risks since the presence of bacteria of the genus Pseudomonas aeruginosa was confirmed. Water treatment reduced the total microbial count (TMC) indicator by 3.6 times. However, TMC still exceeded permissible levels in the tap water, indicating that the drinking water is sanitary and epidemiologically not acceptable. Pathogenic contamination of drinking water can severely affect weaker individuals and children. It has been estimated that the infant mortality rate in Kazakhstan is six times higher as compared to the EU and less than 30% of Kazakhstan’s population have access to safe water. Also, 50% of the population drink water that does not comply with the international standards, e.g., bacteriological levels. Thus, it is important to continuously monitor the groundwater quality to minimize health risks and work towards access to safe drinking water, in line with the UN SDGs.

The Shulbinsk Hydroelectric Power Plant (HPP) located on the Irtysh River in the eastern part of Kazakhstan is one of the largest and oldest hydropower plants in the country. The efficiency of water management systems in the Shulbi reservoir heavily depends on discharge of the Oba and Ulbi rivers, which are the right-hand tributaries of the Irtysh River. This region is characterized by a sparse network of observation stations, which do not allow to fully represent hydrological processes occurring in the area, and therefore planning of adaptation measures related to climate change could be problematic. To overcome this limitation, our study uses the available high-resolution global climate dataset WATCH and explores the possibility of using the Soil and Water Integrated Model (SWIM) to predict river discharge in the basins of the Oba and Ulbi rivers. SWIM was calibrated and validated for the entire Oba and Ulbi river basins. The period from 1962 to 1971 was used as a calibration period, and the period from 1972 to 2016 as a validation period considering every decade separately. The Nash and Sutcliffe efficiency (NSE) and relative volume error (RVE) were used to assess performance of the model. The calibration results showed a good agreement between the modeled and observed discharge with NSE of 0.86 and RVE of 5.6 % for the Oba River and NSE of 0.84 and RVE of 0.2 % for the Ulbi River. The analysis of modelling results shows that also the high flow indices Q10 and Q5 corresponding to 90th and 95th percentiles, respectively, are represented sufficiently well by the model SWIM. Based on the obtained results, we can conclude that the model could be successfully applied for predicting discharge and high flows of both rivers in the coming decades, and for projecting discharge in the future under climate change scenarios. Copyright © 2023, Authors. All rights reserved.

Paleoseismic studies are essential to improve earthquake hazard mitigation, a challenging task in the Tian Shan mountains characterized by numerous active faults, frequent strong earthquakes, and abundant triggered landslides. Here, we date the debated formation of Kaindy Lake, the famous landslide-dammed lake in southeastern Kazakhstan, included in the UNESCO World Network of Biosphere Reserves. Our dendrochronological study compares ring-width patterns from dead trees (Picea schrenkiana) still standing in the lake with living trees growing on surrounding slopes and other trees on the landslide debris. Our results place the formation of the lake to just after 1888 A.D. (the last ring of sunken trees) and before 1898 A.D. (the first established trees on the landslide), a period for which only the 1889 A.D. Chilik earthquake (M 8.2) has been reported and caused extensive damages in the region (surface ruptures, landslides). Thus, we propose that the landslide was triggered during this historical earthquake, questioning the previously preferred date of 1911 A.D., and the local common belief. Furthermore, our results indirectly complement previous paleoseismic studies at 8.5 km away, for which the most recent event in the region was poorly defined by geochronological dating, but suggested a surface rupture associated with the 1889 A.D. earthquake. The proximity of the landslide to the surface rupture would place it in the epicentral zone of the Chilik earthquake.

Folate receptor α (FRα) is overexpressed on numerous tumorous cell types such as ovarian or endometrial cancer cells. Moreover, FRα is absent from most healthy tissues as it is normally expressed only on the surface of proximal tubules cells of kidneys and choroid plexus. Thus, folate-based radiopharmaceuticals have emerged this last two decades as FRα is a target of choice to diagnose and treat numerous cancers. Nuclear imaging is a performing diagnostic technology using highly sensitive detectors and specific radiopharmaceuticals used to detect tumors at an earlier stage. Herein, an overview of the development of folate-based radiopharmaceuticals to detect FRα-positive tumors by nuclear imaging using positron emission tomography (PET) and single photon emission computed tomography (SPECT) is exposed. Strategies developed to improve precursor synthesis, bioavailability, clearance, and affinity to FRα will be detailed. Advances made to decrease kidney uptake open the gate to targeted radionuclide therapy (TRT) using folate-based radiopharmaceuticals to treat FRα-positive tumors. Thus, radiofolates used in TRT and more precisely in a theranostic approach will be depicted in this review.

Purpose. Increasing oil recovery from reservoirs, reducing water content, and decreasing costs by pumping formation water effectively cleaned of suspended solids allows you to get a picture of the uniform distribution of water over the reservoir and, in general, the quality maintenance of reservoir pressure in productive reservoirs. Methodology. The study on water treatment issues for maintaining reservoir pressure at existing oil fields has a variety of approaches. Therefore, the methods of analysis, review, comparison, modeling, experiment were used in the work. The analysis method made it possible to divide the problems of approaches to the formation water preparation for its injection into the reservoir into many elements, which made it possible to learn their properties, connections and relationships. This method contributes to a more detailed structuring of the problem of water treatment. The analogy method uses the study of the technology of preparation of reservoir water with suspended solids. Based on the data, an effective technology was studied for treating formation water from suspended solids and injecting it into a productive formation. Findings. The experiments carried out reflect the high-quality water preparation using the developed new industrial sand-gravel filter made of granular materials with variable particle sizes in the vertical direction, taking into account the rational parameters of the column height of the filter working area. The regularities were studied and the process of formation water preparation without suspended solid particles was improved on the basis of the theoretical and experimental studies carried out on a special laboratory unit. The dependence of the reservoir permeability in the bottomhole zone of injection wells on the size of solid suspended particles in the injected water was determined, and rational filter parameters were established for preparing injected water without suspended solid particles into the reservoir using granular materials with a variable fraction and water supply from the bottom up. Originality. An effective technology for deep purification of formation water from suspended clay particles is proposed by using filters made of granular materials with a variable particle size. The technical result of the invention is to increase the efficiency of purification of industrial waste and industrial formation waters with suspended solids. Practical value. A new method for deep formation water treatment is proposed, which ensures the capture of suspended solids. The results of experiments on establishing the regularity of the process of formation water filtration with suspended clay particles through a porous medium with variable pore sizes and granular particles are presented. A recommendation has been developed for choosing rational parameters and operating modes of a new filter for formation water treatment.