This review highlights advancements in ethylene removal technologies tailored for fruit and vegetable (F&V) preservation, with a focus on physical adsorption and chemical elimination methods. Conventional approaches, such as potassium permanganate (KMnO₄) and 1-methylcyclopropene (1-MCP), are limited by toxicity concerns, declining efficiency, and potential fruit disorders. Emerging alternatives, particularly catalytic oxidation using metal oxide catalysts like TiO₂, offer efficient ethylene degradation into non-toxic byproducts. Incorporating these catalysts with porous materials, such as zeolites, enhances ethylene adsorption while providing multifunctional benefits, including antibacterial activity. In addition to discussing the materials of the adsorbents, their binding mechanisms (such as van der Waals forces and π-complexation) were also studied. Future research directions include improving cost-efficiency, optimizing material performance for practical applications, and ensuring food safety in packaging systems. These advancements represent a sustainable strategy to extend the shelf life of F&V in the postharvest supply chain. © 2025

To conduct a qualitative and quantitative assessment of surface waters in the catchment areas of the lower reaches of the Syrdarya River, research bases have been created for the hydrological posts of Shardara, Kyzylorda and Kazaly based on the annual report «Aral-Syrdarya Basin Inspectorate for the Rational Use and Protection of Water Resources» of the Water Resources Committee Ministry of Geology, Ecology and natural resources of the Republic of Kazakhstan in the period 1996–2020 and used integral hydrochemical indicators of the water pollution index, the coefficient of maximum water pollution, the coefficient of maximum permissible water pollution and the Shannon trophic index, taking into account the regulatory criteria for maximum permissible concentrations for fisheries water use. The obtained results show that in modern conditions of the catchment areas of the lower reaches of the Syrdarya River, despite the quantitative indicators of water quality for all indicators, it has a negative trend, does not meet regulatory requirements, since pollution varies from the level from «polluted» to «moderately polluted», in general, not suitable for drinking water supply, and the ecological situation changes from «eutrophic» to «mesotrophic», indicating, as a rule, the degree of influence of anthropogenic activity is within the limits of uncontrolled and unaccounted for consequences (deterioration in the quality of water and land resources, as well as agricultural products)., which has become the reason for the impossibility of fulfilling the environment-forming and ecological functions of the surface waters of river basins. © National Academy of Sciences of the Republic of Kazakhstan, 2023.

This paper presents data on the isotopic composition of fresh and mineral groundwater in the Mangystau region. The least studied component of the hydrologic cycle is groundwater involvement. Isotopes of natural origin are used as indicators to find out whether groundwater is replenished, its genesis, how it moves, whether it is at risk of pollution, and whether it is susceptible to changing climatic conditions. Waters of different genesis have specific isotopic signatures that leave a unique “footprint”. This is used to track the movement of water throughout the entire hydrologic cycle-evaporation, burial, infiltration, runoff, evapotranspiration, etc. This paper presents the results of a study of groundwater genesis using a comprehensive approach that would be relatively inexpensive and not require long observation cycles. In this case, to study the rates of water exchange and groundwater formation conditions in the Mangystau region used data on the chemical and isotopic composition of water (18O,2H), and the concentration of tritium (3H), obtained by sampling in September 2021 The sampled areas are located within the Mangystau-Ustyurt hydrogeological basin, which occupies the southwestern part of the vast Turan plate and is located south of the Caspian hydrogeological basin. Analysis of isotopic compositions (contents of deuterium, oxygen-18 and tritium) of water samples was performed at the Institute of Radiation Safety and Ecology (National Nuclear Center of the Republic of Kazakhstan) on a high-sensitivity laser spectrometer LGR 912-0008. VSMOW standards were used as reference standards, Measurement of radionuclide3H was carried out on liquid scintillation beta spectrometer TRI-CARB 2900TR. © 2022, National Academy of Sciences of the Republic of Kazakhstan. All rights reserved.

The development of bio-derived composites represents a sustainable and cost-effective strategy for advanced energy storage applications. In this work, a porous carbon/nickel oxide (NiO) composite was synthesized from orange peel via carbonization at 500 °C followed by KOH activation at 700 °C and subsequent hydrothermal NiO modification. The resulting material exhibited a hierarchical porous structure with a high specific surface area (2120 m2 g−1 for OP_500_700 and 1968 m2 g−1 for NiO-modified OP_500_700_0.1M), with both values being significantly higher than that of the non-activated OP_500 (3.40–18.12 m2 g−1). Electrochemical evaluation revealed that the NiO-functionalized composite achieved a specific capacitance of 306.0 F g−1 at 5 mV s−1 and 281.5 F g−1 at 2 A g−1, surpassing the pristine activated carbon (281.9 F g−1 and 259.6 F g−1, respectively). In addition, both electrodes demonstrated excellent cycling stability, retaining more than 80% capacitance after 5000 charge–discharge cycles at a high current density of 20 A g−1, while the NiO-modified electrode further benefited from a self-activation effect leading to >100% retention. These findings emphasize the synergistic effects of hierarchical porosity and NiO pseudocapacitance, establishing orange peel-derived carbon/NiO composites as scalable and sustainable electrode materials for next-generation supercapacitors.

The peculiarities of the formation of the mineral composition of mine waters are considered. The main processes for cleaning mine water and the factors that influence the choice of cleaning methods and schemes are listed. This article provides a mathematical evaluation of the efficiency of ozonator control via a sensor network during the process of underground water purification in mines over a 10-minute period. The aim of the study is to monitor the ozone concentration precisely, enhance water purification efficiency, and conserve energy. The ozone concentration decreased from 1 to 0.2 within the first 5 minutes, while the purification quality reached 0.8 during this time. Energy efficiency increased to 0.35 within the first 2 minutes, but gradually decreased, reaching approximately 0.2 by the 10th minute. Throughout the study, real-time monitoring of the ozone levels via the sensor network allowed for process optimization. The results demonstrated the effectiveness of sensor-based control in preventing excessive ozone consumption and improving water quality. In conclusion, ozonator control through a sensor network was proven to be an environmentally friendly and energy-efficient method.

Acoustic emission systems and complexes are currently considered a sensitive method for detecting forming defects. However, defect detection in selective laser melting of heat-resistant alloys using acoustic emission becomes challenging under the influence of noise. The impact of noise significantly complicates the identification of factors influencing the defect formation process, and it also makes it much harder to interpret the parameters of acoustic emission that characterize the state of the object under control. Objective. Study of filtering methods in case of extraneous influences to improve the reliability of the results of recording acoustic signals and improve the identification process. Methods. This article presents the results of the implementation of the developed method of cascade digital filtering. The method is based on high-frequency digital filters, approximated by a second-order Butterworth polynomial model. Amplitude, time, and frequency fragments of acoustic emission signals, which characterize the defect formation process during the manufacturing of products, are highlighted. A relationship between the measurements of the signal’s amplitude parameters, the laser power of the system, and the nitrogen content in the heat-resistant alloy is established. The dependence of the laser power and nitrogen content percentage is approximated using the least squares method and visualized based on a scatter plot. Results and conclusions. The developed relationship describes and characterizes the influence of the listed factors on the defect formation process, and its adequacy is confirmed by calculating the coefficients of determination and significance. It is shown that the application of the cascade filtering method for signal identification significantly increases the effectiveness of the acoustic emission method. The developed cascade filtering method can also be applied when studying the acoustic properties and stresses caused by the physical fields of various rocks.

Polysaccharides such as chitosan (Ch) and gellan gum (GG) were chemically modified to produce water–soluble amphoteric polyelectrolytes. These derivatives were synthesized via carboxymethylation and quaternization reactions and characterized using techniques including 1H NMR, FTIR spectroscopies, elemental analysis, potentiometric titration, and thermogravimetric analysis (TGA). The degree of quaternization of gellan gum (QGG) with trimethylammonium groups was determined to be ~38% as by 1H NMR spectroscopy; ~35% based on potentiometric titration, and ~39% according to elemental analysis. Similarly, the degree of carboxymethylation of chitosan (CMCh) was calculated as ~37% according to 1H NMR data, while back potentiometric titration provided a value of ~35%. The modified polysaccharides exhibited distinct isoelectric points (pHIEP) as determined through electrophoretic mobility measurements and conventional viscometric analysis. The data collected from both techniques were in good agreement indicating pHIEP = 2.0–2.5 for the modified gellan gum and pHIEP = 7.0 for the modified chitosan. Amphoteric Ch and GG were used to stabilize spherical (AuNSs) and rod-like (AuNRs) gold nanoparticles, synthesized using “one-pot” and seed-growth methods, respectively. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) confirmed particle binding to the modified polymers. The average diameters of AuNSs stabilized with QGG and CMCh were ~45 and 85 nm, respectively, whereas AuNRs stabilized by QGG and CMCh exhibited dimensions of ~50–55 nm (length) and ~12–14 nm (width). These findings suggest that amphoteric QGG and CMCh-stabilized AuNSs and AuNRs could potentially be used as effective photothermal agents for treating Ehrlich cancer cells, as previously reported by our research group (Macromolecular Chemistry and Physics, 2024, 2400128).

Large volume changes, the insulating nature of sulfur, and the lithium polysulfides (LiPSs) shuttle effect significantly hinder the practical application of lithium-sulfur (Li-S) batteries. In this study, reduced graphene oxide/MXene (rGO/MXene) composites were investigated as potential sulfur host materials. Since the rGO-to-MXene ratio influences electrical conductivity, LiPSs confinement, and structural stability, MXene contents of 10 wt%, 20 wt%, and 30 wt% were systematically evaluated. The (rGO/MXene10)_S60 electrode exhibited the most promising performance, delivering an initial discharge capacity of 981 mAh/g and retaining 606 mAh/g after 100 cycles with Coulombic efficiency (CE) above 97 %. These results demonstrate that a 9:1 rGO-to-MXene ratio optimally enhances conductivity, structural stability, and LiPSs anchoring, making it a promising sulfur host for Li-S batteries.

This paper examines the integration of artificial intelligence (AI) in ankle rehabilitation exoskeletons. Special attention is given to modern AI technologies such as machine learning algorithms, adaptive control systems, neural networks, and data analysis, which significantly enhance the effectiveness and personalization of rehabilitation. Exoskeletons equipped with these technologies are capable of more precise motion tracking, adapting treatment in real time, and predicting patient movements, making rehabilitation safer and more comfortable. In addition to a comprehensive review of existing solutions, this study presents an AI-based ankle rehabilitation exoskeleton prototype developed as part of our research. The prototype integrates AI-driven adaptive control methods and sensor-based movement analysis to enhance rehabilitation efficiency.

The object of the study is the design, manufacturing technology and methods of stabilizing the electrophysical characteristics of measuring transducers. The problem solved in the research is the creation of methods and design and technological solutions to ensure stability used in the development and manufacture of measuring transducers. As a result of the conducted research, designs and technologies for manufacturing and stabilizing the electrophysical characteristics of measuring transducers were developed. The features of the developed designs of measuring transducers are increased in comparison with the known time stability with a basic error of no more than 0.1 %/year. Technologies for stabilizing the parameters of measuring transducers, in contrast to the known ones, differ in their versatility, since most elastic elements that perceive mechanical magnitude are membranes and beams, on which thermocompensating films are easily applied. The stabilization of the parameters of the entire measuring transducer, unlike the known ones, is carried out after the removal of internal mechanical stresses of each element and part of the measuring transducer through the integrated use of current and vibration dynamic loads. Thus, the use of complex compensation due to the application of a new method of compensation of internal mechanical stresses in the structure, based on the use of multilayer film compositions formed on sensitive elements, followed by thermal and vibration stabilization of measuring transducers. In addition, reducing the measurement error and increasing the time and parametric stability of the measuring transducers is achieved through the use of specialized heat treatment modes, training resonant vibration and current loads. When developing structures and stabilization methods, previously developed engineering mathematical models were used, including constructive, informational, dimensional, technological and circuit engineering. At the same time, depending on the adopted design and the technology used, engineering models were modified by including known coefficients and dependencies. This method has significantly reduced the cost and complexity of development