Over the past two centuries, photocatalysis—the use of light to accelerate chemical reactions—has undergone substantial development. This multidisciplinary field, which is especially thriving with advances in nanotechnology, combines photochemistry, catalysis, and semiconductor physics. Calcium ferrite's low band gap and strong activity underneath sunlight make it a suitable for photocatalytic applications. The effectiveness of calcium ferrites and the related photocatalysts in organic pollution remediation, synthetic techniques, and their photocatalytic characteristics, including the processes governing their activity, are all covered in this paper. Numerous synthesis methods have been explained, including sol-gel, co-precipitation, and hydrothermal processes. The optical and structural characteristics have been examined using characterization methods like as UV–Vis spectroscopy and X-ray diffraction (XRD). The review demonstrates calcium ferrites' potential in environmental remediation technologies by highlighting how well it breaks down organic contaminants in water purification and, at the end, the challenges and future outlooks have been mentioned.

Due to the side effects of greenhouse gases, interest in alternative energy sources is growing, and research into hydrogen (Н2) production from cyanobacteria has become a promising direction for the industry. The article provides an overview of cyanobacterial hydrogen production strategies and their current economic efficiency. It also describes metabolic, genetic and technical methods for obtaining H2 from cyanobacteria. Cyanobacteria are considered potential producers of hydrogen energy that will be economically viable shortly, as they only need cheap salts, water and solar energy to grow. However, producing hydrogen from cyanobacteria still requires extensive work, and the main problem is the small amount of hydrogen energy obtained. To produce large amounts of cyanobacterial hydrogen, the most active wild-type strains must be selected and technological, modular and genetic research must be carried out simultaneously. The low energy efficiency of hydrogen from cyanobacteria also shows the need for comprehensive research through international programs. © 2022 Hydrogen Energy Publications LLC

The dependences of changes in the strength properties of nitride and carbide ceramics under high temperature irradiation with Kr15+ and Xe22+ heavy ions at irradiation doses of 1012–1015 ions/cm2 are presented in this work. The irradiation was chosen to simulate radiation damage processes that are closest to the real conditions of reactor tests in operating modes of increased temperatures. Polycrystalline ceramics based on AlN, Si3N4 nitrides, and SiC carbides were chosen as objects of research, as they have great prospects for use as a basis for structural materials for high-temperature nuclear reactors, as well as materials for nuclear waste disposal. During these studies the effect of radiation damage caused by irradiation with different fluences on the change in mechanical strength and hardness were determined, and the mechanisms causing these changes depending on the type of irradiated materials were proposed. The novelty of this study is in the results obtained determining the stability of the strength and thermophysical parameters of nitride and carbide ceramics exposed to high-temperature irradiation, which made it possible to determine the main stages and mechanisms for changing these parameters depending on the accumulated radiation damage. The relevance of this study consists not only in obtaining new data on the properties of structural materials exposed to ionizing radiation, but also in the possibility of determining the mechanisms of radiation damage in ceramics. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

This paper describes research work to determine the corrosion compatibility of material of the capillary-porous structure (CPS) matrix with a liquid tin-lithium (Sn-Li) alloy at high temperatures. The studies were carried out with the Sn-Li alloy containing 73 at.% of tin and 27 at.% of lithium and samples of 12Cr18Ni10Ti grade austenitic stainless-steel. This steel was proposed as one of the options as a candidate material for the Sn-Li CPS matrix manufacturing. Experiments on the interaction of a liquid Sn-Li alloy with stainless-steel at high temperatures were carried out on the TiGrA experimental facility based on the Mettler Toledo TGA/DSC 3+ thermogravimetric analyzer. The temperature gap in corrosion experiments ranged from 600 °C to 1000 °C, the interaction time for each temperature level was about 10 h. In the course of the work, experiments were carried out to study the compatibility of a Sn-Li alloy in the liquid phase with stainless-steel at temperatures of 600 °C, 800 °C and 1000 °C. Post-experimental studies of stainless-steel samples were carried out using microstructural and energy-dispersive analysis. Based on the results obtained, it was determined that when stainless-steel interacts with an Sn-Li alloy at high temperatures, complex physical-chemical processes occur, such as: selective dissolution of steel components by a liquid alloy; permeation of the liquid alloy into stainless-steel; mass transfer of dissolved metals from a solid metal to a liquid one

Miscible carbon dioxide (CO2) flooding is a well-established and promising enhanced oil recovery (EOR) technique whereby residual oil is recovered by mixing with injected CO2 gas. However, CO2, being very light and less viscous than reservoir crude oil, results in inefficient sweep efficiency. Extensive research is ongoing to improve CO2 mobility control such as the development and generation of CO2/water foams. The long-term stability of foam during the period of flooding is a known issue and must be considered during the design stage of any CO2 foam flooding project. The foam stability can be improved by adding surfactants as stabilizers, but surfactants generated foams have generally a shorter life because of an unstable interface. Furthermore, surfactants are prone to higher retention and chemical degradation in the porous media, particularly under harsh reservoir conditions. Research has shown that nanoparticles (NPs) can act as an excellent stabilizing agent for CO2/water foams owing to their surface chemistry and high adsorption energy. The foams generated using NPs are more stable and provide better mobility control compared to surfactant-stabilized foams. One limitation of using NPs as foam stabilizers is their colloidal stability which limits the use of low-cost NPs. Combining surfactants and NPs for CO2 foam stabilization is a novel approach and has gained interest among researchers in recent years. Surfactants improve the dispersion of NPs in the aqueous phase and minimize particle aggregation. NPs on the other hand create a stable barrier at the CO2/water interface with the help of surfactants, thus generating highly stable and viscous foams. This paper presents a comprehensive review of the basic principles and applications of stabilized CO2 foams. A brief overview of CO2 foam flooding is discussed first, followed by a review of standalone surfactant-stabilized and NPs-stabilized CO2/water foams. The application of hybrid surfactant-NPs stabilized CO2 foams is then presented and areas requiring further investigation are highlighted. This review provides an insight into a novel approach to stabilize CO2/water foams and the effectiveness of the method as proved by various studies. © 2021 Chinese Petroleum Society

These studies were carried out within the framework of non-competitive program-targeted funding on the topic: ‘Assessment of seismic hazard of territories of regions and cities of Kazakhstan on the modern scientific and methodological basis. 2021-2023’. The work presents the results of seismic hazard assessment, for the first time carried out on a new methodological basis, corresponding to the provisions of Eurocode 8 (EN 1998-1:2004) ‘Design of seismic resistant structures’ and coordinated with the modern maps of the general seismic zoning of countries of the EurAsEC and the Customs Union, for use in design and construction practice in Kazakhstan. The main distinctive elements are the probabilistic approach to the calculation of seismic hazard and the characterization of the hazard in the quantitative parameters of ground vibrations in addition to macroseismic characteristics. The result of the seismic hazard assessment is a set of maps that allows rational planning of civil and industrial developing of different areas and estimation of the total costs required for anti-seismic measures of a national scale. Such maps illustrate regional differences in the amplitude of ground oscillations with a constant recurrence period of seismic shaking (i.e., a constant probability of exceeding the seismic effect). The RK seismic zoning maps are of great practical value and are intended for the administrative bodies that regulate construction works of residential and industrial facilities, as well as for design and architectural organizations that develop documentation for earthquake-proof construction of civil and industrial structures and allow more efficient investment in capital construction, taking into account the available assessment of potential seismic hazard using bothMSK-64 scale points and engineering characteristics. © National Academy of Sciences of the Republic of Kazakhstan, 2022.

This study investigates the perceptions of higher education students regarding an interactive DC (Direct Current) motor simulator, shedding light on the evolving landscape of virtual education. By utilizing five aspects of learning dimension, visual elements, software functionality, usability, and portability of a four-point Likert scale questionnaire, the research uncovers a generally positive reception of the simulator among students, who view it as a valuable complement to traditional hands-on laboratories, enabling self-paced learning and offering repeatable experiments in a safe environment. Nevertheless, our research highlights notable concerns, such as challenges related to user interface design and pre-installation software. These findings offer crucial insights into the strengths and limitations of a DC motor simulator in higher education, providing guidance for educators and instructional designers striving to optimize digital learning experiences. © 2024 Didik Hariyanto et al; published by UIKTEN. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 License.

Inexpensive and efficient desalination is becoming increasingly important due to dwindling freshwater resources in view of climate change and population increase. Improving desalination techniques of brackish water using graphene-based materials has the possibility to revolutionize freshwater production and treatment. At the same time, graphene matter can be cheaply mass-produced from biowaste materials. In view of this, graphene material was obtained from a four-step production approach starting from rice husk (RH), including pre-carbonation, desilication, chemical activation, and exfoliation. The results showed that the produced samples contained a mixture of graphene layers and amorphous carbon. The activation ratio of 1:5 for carbonized RH and potassium hydroxide (KOH), respectively, provided higher graphene content than the 1:4 ratio of the same components, while the number of active layers remained unaffected. Further treatment with H2O2 did not affect the graphene content and exfoliation of the amorphous carbon. Preparation of the graphene material by the NIPS technique and vacuum filtration displayed different physicochemical characteristics of the obtained membranes. However, the membranes’ main desalination function might be related more to adsorption rather than size exclusion. In any case, the desalination properties of the different graphene material types were tested on 35 g/L saltwater samples containing NaCl, KCl, MgCl2, CaSO4, and MgSO4. The produced graphene materials efficiently reduced the salt content by up to 95%. Especially for the major constituent NaCl, the removal efficiency was high.

Even though natural sources of air pollution account for over 50% of sulphur compounds, 93% of nitrogen oxide which are the most dangerous artificial anthropogenic sources of air pollution and primarily associated with the combustion of fossil fuel. Coal-fired thermal power plants and industrial fuel-burning plants that emit large quantities of nitrogen oxides (NО and NО2), solids (ash, dust, soot), as well as carbon oxides, aldehydes, organic acids into the atmosphere pollute the environment in majority. In the present work, a mathematical model and a scheme for calculating the formation of nitrogen oxide has been developed. Also, the dependence of the rate of release of fuel nitrogen from coal particles at the initial stage of gasification and content of volatiles has been obtained. The main regularities of the formation of NOx at the initial section of the flame in the ignition zone of the swirl burner flame during the combustion of Ekibastuz coal have been revealed. Modern environmental requirements for the modernization of existing and the creation of new heat and power facilities determine the exceptional relevance of the development of effective methods and constructions to reduce emissions of nitrogen oxides, sulfur oxides and ash to 200, 300, and 100 mg/nm3 at a = 1.4. The dust consumption in all experiments was kept constant and amounted to 0.042 g/s, as well as with the results of calculating the thermal decomposition of the Ekibastuz coal dust, the recombination of atomic nitrogen into nitrogen molecules, and the kinetics of the formation of fuel nitric oxide. It was found that despite the presence of oxygen in Ekibastuz coal for gases Odaf = 11.8% in an inert atmosphere, nitrogen oxides are not formed. © The Author(s) 2021.

This article reviews research studies on compression heat pump-assisted thermal desalination systems. The reported studies are grouped as follows: (a) compression heat pump-assisted regenerative solar still thermal desalination; (b) compression heat pump-assisted humidification–dehumidification thermal desalination; (c) compression heat pump-assisted air conditioning and thermal desalination; (d) compression heat pump-assisted vacuum thermal desalination; (e) compression heat pump-assisted membrane thermal desalination; (f) compression heat pump-assisted freezing thermal desalination; and (g) compression–absorption and compression–adsorption hybrid heat pump-assisted thermal desalination. The schematics of the new configurations are included. Moreover, the economic and environmental assessments for compression heat pump-assisted thermal desalination systems are presented. Based on the review, the current status, challenges and future research scope in the field of compression heat pump-assisted thermal desalination systems are described. This review concludes that compression heat pumps are energy-efficient heat regeneration equipment that can be integrated with thermal desalination systems to produce potable water. The details reported in this paper are useful for consultants, researchers and industrial experts working in thermal desalination. © Akadémiai Kiadó, Budapest, Hungary 2024.