Various toxic pollutants such as dyes, pesticides, polycyclic aromatic hydrocarbons (PAHs), substituted phenols, and pharmaceutical waste were discharged into the water bodies and impose serious health hazards to humans as well as to the environment. Therefore, it is crucial to identify sustainable treatment methods for the removal of these harmful pollutants. The reduced graphene oxide (r-GO) based composites have demonstrated improved strength, durability, flexibility, resistance to heat, UV radiation, fire, and electrical and thermal conductivity. Therefore, function as an efficient electron acceptor, enhancing photo induced charge transfer, impeding charge carrier recombination, boosting photocatalytic activity and increasing specific surface area for photocatalytic degradation and adsorption of wastewater pollutants. This review article summarizes the unique properties and green synthesis of r-GO based engineered nanomaterials to lessen toxic organic wastewater pollutants along with their environmental risk assessment for understanding the urgent need for their removal. The previous research and study in this enormous field has been evaluated scientifically and analyzed for finding research gaps. Photocatalysis, an eco-friendly and sustainable method was assessed as an effective method with detailed mechanism by employing solar-activated synthetic nanocomposite of r-GO@metal oxides (CaO, ZnO, Fe2O3, SnO2, TiO2, MgO) with characteristics of low-cost, fast, and efficient for improved adsorption and degradation. This research further assesses degradation routes for various toxic pollutants and active species involved in breakdown into safer metabolites along with the sustainability of r-GO based composites. © 2024 Elsevier Ltd

Kazakhstan's solar energy sector is rapidly advancing due to its vast territory and high solar radiation levels in its regions. The progress achieved to date has been primarily driven by large-scale solar power plants. However, further growth in solar energy also requires the development of small-scale projects. Therefore, this study explores the feasibility of deploying rooftop PV panels in the country. It analyses the current situation of solar sector and examines the impact of solar radiation intensity on panel temperature. The analysis is based on field measurements and simulations using PVsyst software. The innovation of the research is in assessing solar activity in the selected region, analysing the effect of solar radiation intensity on the efficiency of rooftop PV installations and studying the influence of panel characteristics on heating. Results show that in summer, solar irradiance reaches 786 W/m2, and ambient temperature rises to 33 °C, causing panel surfaces to heat up to 46 °C. Total energy loss is 17 %, with 7 % attributed to overheating. System efficiency decreases by 5–10 % due to high radiation. The study concludes the need for panel cooling technologies, higher-efficiency PV modules, and highlights the importance of policy and technological advancements to support small-scale solar installations. © 2025 Elsevier Ltd

The Turkestan lynx (Lynx lynx isabellina Blyth, 1847) is a rare and understudied subspecies of the Eurasian lynx occupying the mountains of Central and South Asia. This elusive felid’s northwestern range includes the Tien Shan and Zhetisu Alatau mountains in the border region of Kazakhstan, China, Kyrgyzstan, and Uzbekistan. As the first step to conserve this vulnerable carnivore, we have conducted the first full-scale research from 2013 until 2022 on its distribution in this region. Using 132 environmental predictors of 359 lynx sightings, we have created species habitat distribution models across the lynx’s northwestern range using machine learning approaches (Maximum Entropy—MaxEnt). Additionally, we created species distribution forecasts based on seven bio-climatic environmental predictors with each three different future global climate model scenarios. To validate these forecasts, we have calculated the changes in the lynx distribution range for the year 2100, making the first species distribution forecast for the Turkestan lynx in the area. Additionally, it provides insight into the possible effects of global climate change on this lynx population. Based on these distribution models, the lynx population in the Northern and Western Tien Shan and Zhetisu Alatau plays a significant role in maintaining the stability of the whole subspecies in its northwestern and global range, while the distribution forecast shows that most lynx distribution ranges will reduce in all future climate scenarios, and we might face the Turkestan lynx’s significant distribution range decline under the ongoing and advancing climate change conditions. For a future (year 2100) warming scenario of 3 deg. C (GCM IPSL), we observe a decrease of 35% in Kazakhstan, 40% in Kyrgyzstan, and 30% in China as the three countries with the highest current predicted distribution range. For a milder temperature increase of 1.5–2 deg. C. (GCM MRI), we observe an increase of 17% Kazakhstan, decrease of 10% in Kyrgyzstan, and 57% in China. For a cooling scenario of approx. 1–1.5 deg. C (GCM MIROC), we observe a decrease of 14% Kazakhstan, increase of 11% in Kyrgyzstan, and a decrease of 13% in China. These modeled declines indicate the necessity to create new and expand the existing protected areas and establish ecological corridors between the countries in Central and South Asia. © 2022 by the authors.

This article discusses the construction of a dynamic model for controlling the position of the blades of a vertical-axis wind generator using an automatic approach; a method is presented that relates the rotation of the motor to the position of the blades, which allows the optimization of the operation of the control system. In the research process, an automatic approach is used, which makes it possible to carry out numerical calculations that predict the behavior of the system at various values of motor rotation. The model allows us to analyze the dependence of the position of the blades on the rotation of the motor and determine the optimal parameters of the mathematical control model. The main goal of our study is to develop a mathematical model of the mechanism for further adjustment of the wind turbine blade position control system depending on the wind speed. © 2023 by the authors.

People with walking disorders caused by accidents or stroke can undergo treatment to restore their mobility. Traditional therapy is time-consuming and time-consuming. Therefore, a new trend was born - to facilitate rehabilitation and reduce the patient's time. Rehabilitation robotics is an area that is constantly evolving, and new mechanisms have recently been developed to help people regain their mobility. This paper presents a 3-RPS parallel manipulator for the restoration of the ankle joint with three degrees of freedom. Parallel manipulator 3-RPS with three degrees of freedom, which was introduced by K. Hunt in 1983 as one of the sedentary parallel manipulators. Since then, 3-RPS has attracted a lot of attention from robotics and biomedical engineering engineers. Copyright © 2023 Nursultan Zhetenbayev, et al.

This article presents the possibility of increasing the efficiency of a vertical-axis wind generator through the introduction of an automatic control system for the angle of attack of the blades. The calculation of the optimal position of the wind turbine blades for the maximum generation of electrical energy is given, and a developed scheme for controlling the blades using the sensors of the angular speed of rotation of the wind wheel by the anemometer and the current position of the blades is presented. The automatic control system implies the use of a PD controller. A comparison is made of two laboratory experimental models of vertical-axis wind turbines with and without the developed control system. This article focuses on optimizing the angle of attack and developing an automatic control system for vertical-axis wind turbines to increase their efficiency in generating electrical energy. © 2023 by the authors.

The challenge of a good quality drinking water supply to southeastern Kazakhstan’s local population from far-away natural surface water sources motivates groundwater utilization from local aquifers. To prevent groundwater resource deficits, artificial groundwater recharge is needed. To this end, infiltration and clogging processes were evaluated through comprehensive field research in southeastern Kazakhstan’s typical river drainage basin (Aksu experimental site). The infiltration scenario included constructed mini pools and their typical soil profile clogging and silting processes. The local aquifer unsaturated and upper saturated zones underwent a detailed study of water balance, hydrodynamic setting, and filtration properties. The research results suggest that the infiltration rate decreased from 15 m/day until the saturation steady state and remained at 0.75 m/day until the end of the experiment. In summer, clogging layers with thicknesses ranging from 3 mm for the clayey silt layer to 6 mm for muddy clay began to form at the mini pools nearly one month after the test began. During infiltration, the mini pools’ upper soil layer dirt-holding capacity varied from 3.72 to 5.25 kg/m2. The field study results serve as a factual basis for artificial replenishment system design and groundwater replenishment methodology optimization in southeastern Kazakhstan and similar regions. © 2022 by the authors.

One of the global problems is environmental pollution by different biowaste. To solve the problem, biowaste must be recycled. Waste-free technology is also a way of saving exhaustible raw materials. Research on electrochemical energy sources is currently the most dynamically developing area of off-grid energy. Electrochemical capacitors can operate for a long time without changing performance, they have smaller dimensions, high mechanical strength, and a wide operating temperature range. These properties are effective energy-saving devices. Therefore, supercapacitors are widely used in various industries. This review discussed the methods of obtaining and the characteristics of biowaste-derived activated carbon and carbon–manganese oxide (AC-MnO2)-based supercapacitor electrodes. © 2022 by the authors.

Sodium-ion batteries (SIBs) offer several advantages over traditional lithium-ion batteries, including a more uniform sodium distribution, lower-cost materials, and safer transportation options. A promising development in SIBs is the use of hard carbons as anode materials due to their low insertion voltage and larger interlayer spacing, which improve sodium-ion insertion. Traditionally, hard carbons are made from costly carbon sources, but recent advancements have focussed on using abundant bio-waste, like coffee grounds. This approach reduces costs and helps manage global waste. This research investigates the electrochemical performance of bio-waste-derived hard carbons, which is significantly impacted by various pre-treatment methods. Techniques such as BET, XRD, TEM, and XPS are employed to examine the effects of pre-treatment variables, including washing solvents (organic, acidic, or distilled water), pre-oxidation temperatures, and post-heating processes. These factors influence the structural properties and purity of the hard carbon, impacting its effectiveness as an anode material in SIBs. A significant finding is a mesoporous hard carbon produced from coffee grounds that, after washing with distilled water, pre-oxidation at 150 °C, and thermal treatment at 1300 °C in argon, shows a 23% yield, a reversible capacity of 304 mA h g−1, and Initial coulombic efficiency of 78%. This study underscores the importance of pre-treatments in removing impurities and enhancing the material's sodium storage capabilities. © 2025 The Author(s)

Escalating environmental concerns and the depletion of non-renewable resources have intensified interest in sustainable and eco-friendly materials. Cellulose-based hydrogels, renowned for their biocompatibility, biodegradability, and excellent mechanical properties, have emerged as promising candidates for diverse applications, including biomedicine, agriculture, and water purification. This review focuses on methods for extracting nanocellulose from agricultural wastes and their use in creating cellulose hydrogels. Special emphasis is placed on the mechanical, chemical, thermal, and environmental properties of nanocellulose, as well as its applications in packaging materials, medical devices, biocomposites, and filtration systems. The literature review examines cellulose extraction methods, hydrogel properties, and their industrial applications. The key advantages and disadvantages of these methods are identified, and directions for future research are proposed. This work provides a comprehensive overview of the current state of research on cellulose-based hydrogels and contributes to the development of more efficient and sustainable production methods for these materials. © 2025 The Royal Society of Chemistry.