Journal of Chemistry and Technologies

INTEGRATION OF ARTIFICIAL INTELLIGENCE INTO THE TEACHING OF CHEMICAL TECHNOLOGY IN HIGHER EDUCATION: A SYSTEMATIC REVIEW

Michael A. Podzharsky — Sun, 22 Mar 2026 00:00:00 +0200

This article analyzes the strategic importance and practical aspects of incorporating artificial intelligence (AI) technologies into the training of chemical engineering students at higher education institutions. The study is based on a systematic scoping review of scientific publications from 2021 to 2025. Based on these sources, the author identifies six major applications of AI in education: modeling and optimizing technological processes with machine learning, using digital twins and augmented reality, incorporating generative AI into project-based learning, applying adaptive learning systems, enabling automated assessment, supporting academic integrity. The article provides empirical evidence illustrating the effectiveness of these approaches. Researchers report that machine learning methods can increase reactor design productivity by up to 60 %, and over 90 % of students positively evaluate the use of generative AI in project-based learning. The analysis emphasizes the role of digital twins in creating highly realistic and safe environments for developing professional skills, including those necessary for hazardous industrial settings. The author also examines how Ukrainian universities adopt AI amid wartime conditions and restricted access to in-person learning. Virtual laboratories and digital simulators help students compensate for limited access to specialized equipment. The article offers practical recommendations for educators, such as expanding computational infrastructure, utilizing digital simulators, and fostering collaboration with industry professionals. The author also shares their personal experience teaching with AI-driven adaptive learning. The conclusion emphasizes that, while AI can modernize chemical engineering education, it cannot replace critical thinking. Since AI-generated content often contains inaccuracies, students and instructors must carefully verify information. To reduce the risk of academic dishonesty, the author recommends increasing the proportion of in-person and oral assessments.

EFFECT OF PSEUDOMONAS BACTERIA ON BIODEGRADATION OF POLYMER STRUCTURES

Nataliia B. Mitina, Yuliia O. Minina — Sun, 22 Mar 2026 00:00:00 +0200

The growing accumulation of polymer waste has become a global environmental challenge, necessitating the development of sustainable mitigation strategies. Bioremediation, based on the use of microorganisms to degrade pollutants in soil and water, is considered a promising approach. This study provides a theoretical analysis of current research on the ability of soil microbiota to decompose synthetic polymers and proposes a method for polymer waste degradation using a combined biological system. The approach involves the joint application of Eisenia foetida culture and bacterial strains of the genus Pseudomonas. Polymer–polymer blends based on corn starch were selected as model materials, specifically ethylene–vinyl acetate copolymer (EVA) and chlorinated polyethylene (CPE). Experimental substrate variants were inoculated with Pseudomonas chlororaphis subsp. aurantiaca UKM-9 and Pseudomonas chlororaphis subsp. aureofaciens UKM B-109 at a concentration of 1.1×10⁷ CFU/g of dry substrate. The results demonstrated that E. foetida significantly enhances microbial development, increasing the total microbial count from 10⁷ to 10⁹ CFU/g. This indicates a high adaptive potential of the microbiota to substrates obtained via vermiculture. The biochemical characteristics and taxonomic affiliation of the bacterial strains were confirmed using the oxidase test. It was established that physicochemical parameters of the substrate, including temperature, moisture, electrical conductivity, and pH, play a key role in regulating microbial activity and growth. Significant changes in electrical conductivity (up to 3999 μS/cm in CPE samples) suggest polymer bond cleavage, ion release, and the formation of soluble degradation products. Optical analysis confirmed substantial biodegradation levels, reaching 72.1 % for CPE and 67 % for EVA. The findings demonstrate the high efficiency of combined biological systems in polymer degradation and underline their potential for developing environmentally safe technologies for the management of synthetic polymer waste.

THE USE OF BIOMODIFIED COLLAGEN-CONTAINING RAW MATERIALS IN THE DESIGN OF TECHNOLOGICAL ADDITIVES FOR THE PRODUCTION OF FOOD PRODUCTS

Nadiia А. Dzyuba — Sun, 22 Mar 2026 00:00:00 +0200

Resources of collagen-containing raw materials are quite significant. These include products of secondary fish processing that are not used and not recycled. Therefore, it is necessary to apply special methods of processing collagen-containing raw materials, in particular scales, fins, heads and bones, to obtain a protein product with proper functional and technological characteristics. Today, there are many ways to influence collagen-containing raw materials and obtain collagen preparations for use in the food industry, cosmetology, medicine, etc. The purpose of the work is to scientifically substantiate and experimentally confirm the possibility of obtaining high-quality protein products from collagen-containing raw materials (in particular from fish) by using various methods of its processing. The study used modern standard and generally recognized methods for determining physicochemical and structural and mechanical properties. Studies of the chemical composition of the starting raw materials (fish waste of various species of fish) were conducted. The results of the study indicate the possibility of using this raw material as a component of additive formulations. A study of collagen-containing fish scales was conducted, confirming the possibility of using collagen-containing products as stabilizers. Collagen hydrolysate in the composition of the supplement affects the quality characteristics of finished products. It can be concluded that the use of fish scales to obtain collagen hydrolysate for the production of supplements is possible only if they are pre-processed, namely separated from the fish carcass. The method of obtaining these products determines the directions of their further use. It is possible to use a supplement with collagen hydrolysate obtained from secondary fish raw materials in food production.

CRUELTY-FREE FOIE GRAS: PLANT-BASED ANALOGUE TECHNOLOGY WITH HIGH BIOLOGICAL VALUE

Lyudmyla V. Peshuk, Elena A. Сhernushenko, Alina M. Savchenko — Sun, 22 Mar 2026 00:00:00 +0200

Objective. The aim of the study was to develop a scientifically substantiated technology for producing plant-based imitation foie gras with enhanced biological value and improved sensory properties. Methods. The authors analyzed the chemical composition of raw materials and the finished product, optimized the formulation of the plant-based foie gras analogue, determined physicochemical parameters, calculated the amino acid score, the essential amino acid index, and the energy value of the product. Organoleptic, physicochemical, and biochemical research methods were used to assess product quality. Results. The researchers developed formulations of imitation foie gras based on sprouted legumes (lentils and chickpeas), champignon mushrooms, nuts, vegetable oils, and spices. It was established that sprouting legumes increased the protein content from 24 to 26 %, raised the essential amino acid index from 1.66 to 1.80, and improved the amino acid profile by 12 % compared to unsprouted raw materials. The developed product demonstrated the following physicochemical characteristics: protein content – 6.11 %, fat – 22.20 %, carbohydrates – 13.23 %, fiber – 4.41 %, ash – 1.56 %, moisture content – 51.76 %, and energy value – 277.16 kcal/100 g. Sensory evaluation showed that the sample with the addition of champignon mushrooms had the closest taste, aroma, and creamy texture to traditional foie gras. The product contained no cholesterol, and its lipid fraction was predominantly represented by unsaturated fatty acids. Conclusions. The authors created a technology for producing a plant-based analogue of foie gras that is close to the traditional product in sensory characteristics and meets the requirements for functional foods in terms of nutritional value. The nutritional adequacy of the developed product is confirmed by a balanced amino acid composition of proteins, the absence of cholesterol, and a high content of unsaturated fatty acids and dietary fiber. The proposed formulation can be used in the production of health-oriented and vegan food products.

USE OF ARTIFICIAL INTELLIGENCE IN FOOD TECHNOLOGIES ON THE EXAMPLE OF OPTIMIZING PARAMETERS OF THE ENZYMATIC PROCESS FOR COCOA BUTTER EQUIVALENT PRODUCTION

Pavlo O. Nekrasov — Sun, 22 Mar 2026 00:00:00 +0200

In this study, an approach to intelligent control of biocatalytic processes in food technologies was substantiated and validated using the optimization of enzymatic interesterification for the production of a cocoa butter equivalent in a continuous packed-bed reactor with immobilized lipase. High-oleic sunflower oil and a mixture of ethyl esters of palmitic and stearic acids were used as substrates. The controlled factors were the molar ratio of ethyl esters to oil (4–9 mol/mol), temperature (50–75 °C), and hydrodynamic residence time (15–60 min). The methodological framework was based on integrating artificial intelligence models with an evolutionary optimization method, namely particle swarm optimization. Experimental data were obtained using an orthogonal maximin Latin hypercube design and used to compare nine regression models via nested cross-validation. Support vector regression with a radial basis function kernel provided the highest accuracy and the lowest inter-fold variability. The selected model was used as the fitness function in particle swarm optimization, enabling determination of the optimal enzymatic interesterification conditions: substrate molar ratio of 6 mol/mol, temperature of 65 °C, and residence time of 38 min. A confirmatory experiment verified the adequacy of the model in the vicinity of the optimum: the cocoa butter equivalent yield was 77.0 ± 1.1 %, with a relative deviation of δ = 0.52 %. The results demonstrate the effectiveness of using artificial intelligence to identify optimal parameters of biocatalytic processes in food industry technologies.

COMPLEX PROCESSING AND PROSPECTS OF OAK FRUITS USE IN THE FOOD INDUSTRY

Sun, 22 Mar 2026 00:00:00 +0200

All morphological parts of the oak tree, including fruit, bark, wood and leaves, have many uses. Acorns are rich in nutrients, making them an important raw material resource. Since ancient times, oak fruits have been a valuable food product and today have great potential for use in various industries. Acorn flour is an important gluten-free component of bakery, flour confectionery and pasta products. Acorn starch can be used not only for food purposes, but also find application in the production of bioethanol, in paper production, in the manufacture of composites and polymer films. Acorn extracts exhibit antioxidant properties and are used for medicinal purposes. Oak fruit protein isolates have prospects in the production of food water-fat emulsion products, acorn oil is a source of valuable fatty acids. Acorn drinks - coffee substitutes - are becoming increasingly popular. The analysis of recent publications has shown that the issue of using oak fruits as a multipurpose raw material is given considerable attention. Scientific research is focused on individual processes, or the study of the properties and areas of application of certain compounds of oak fruits. The work is carried out using advanced research methods, they are characterized by the depth of study of the nutritional and technological characteristics of the resulting acorn products. The predictability of their behavior in multicomponent systems is an important characteristic that affects the technology and implementation of innovations in food production. An important task is not to implement separate processes for extracting acorn components, but a comprehensive, ecologically and economically justified waste-free processing of oak fruits into food, pharmaceutical and technical products. Solving this task requires systematization of research results and the formation of flexible approaches to the issue of complex processing of oak fruits.

WEAP BASED ASSESSMENT OF SELF-PURIFICATION PROCESSES IN THE DNIPRO RIVER WITHIN THE CITY OF DNIPRO: ECOTECHNOLOGIES AND DIGITAL WATER MANAGEMENT

Sun, 22 Mar 2026 00:00:00 +0200

This article examines the self-purification processes of the Dnipro River within the Lower Dnipro sub-basin using the WEAP (Water Evaluation and Planning system) modelling environment. The study area is characterized by complex hydrogeological conditions and limited infiltration recharge. Through simulation modelling, the efficiency of biochemical decomposition of organic matter was calculated, and the dynamics of key hydrochemical indicators – biochemical oxygen demand, chemical oxygen demand, and dissolved oxygen – were assessed at control sections located upstream and downstream of the city of Dnipro. The results reveal a extremely low level of natural recovery of the aquatic environment, indicating significant impacts from industrial and municipal discharges, climate change, and the inflow of decomposition products from munitions during military actions. The study underscores the necessity of implementing a comprehensive suite of environmental protection measures – including the application of nature-based solutions, modernization of treatment facilities, digitalization, and automated monitoring – to enhance the river’s self-purification capacity and ensure the sustainable use of water resources. The work also highlights the need for integrated management of the Dnipro River’s water resources within the city of Dnipro in accordance with the provisions of the EU Water Framework Directive, aimed at supporting the region’s sustainable ecological development.

IMPROVEMENT OF TECHNOLOGY FOR SAUSAGES USING FUNCTIONAL INGREDIENTS

Sun, 22 Mar 2026 00:00:00 +0200

The article presents the results of a scientific study aimed at improving the technology of cooked sausage products by introducing functional ingredients of natural origin – rosemary extract and chia seed powder. Particular attention is paid to their effect on physicochemical, technological, microbiological indicators andlipid oxidation indicators (acid and peroxide values) during storage. As part of the experiment, traditional raw materials were partially replaced in two ways: 50 % of vegetable oil was replaced with oil containing 80 % rosemary extract, and semi-fat pork was replaced with gel made from chia seed powder in quantities of 2.5%, 5 % and 7.5 %. The study was conducted on the basis of a control sample manufactured in accordance with the current DSTU. Qualitative and quantitative indicators were assessed using physicochemical, organoleptic, technological and microbiological criteria, as well as oxidative processes dynamics in the lipid fraction of the product. The results showed that the addition of functional ingredients does not worsen , but, stabilises microbiological indicators and does not accelerate oxidative processes during storage. The most balanced functional, technological, sensory and antioxidant properties were found in the sample with 5 % chia powder, where an optimal ratio of moisture retention capacity, structure, oxidation intensity and organoleptic characteristics was observed. The use of oil with rosemary extract provided a pronounced antioxidant effect, increased lipid stability and colour stability, while chia seed powder contributed to a reduction in the proportion of animal fats and an increase in the nutritional and biological value of the products. The practical significance lies in the possibility of implementing the proposed recipe and technological modification in industrial conditions without changing production equipment, which makes the approach technologically and economically feasible. The results obtained can be used to create a line of functional cooked sausage products with improved safety, stability and value.

JUSTIFICATION OF BOILED SAUSAGE TECHNOLOGY WITH INCREASED PROTEIN CONTENT

Sun, 22 Mar 2026 00:00:00 +0200

Boiled sausages are popular meat products among consumers. At the same time, the question arises of increasing the nutritional value, in particular, in terms of protein content, of boiled sausages. The purpose of this work is to substantiate the use of sodium caseinate, amaranth flour, collagen protein, psyllium as dietary fiber, dihydroquercetin and sea salt in the technology of boiled sausage. It was found that the experimental sample had an increased protein content by 2.7 %, a reduced fat content by 4.1 %, and moisture by 2.5 %; improved moisture-retaining (94.8 %) and moisture-binding (82.7 %) capabilities compared to the control sample. Increasing the pH to 6.34 compared to the control sample (6.19) contributed to reducing moisture loss during heat treatment and improving texture. The experimental sample exceeded the control in terms of mass fractions of all essential amino acids: valine – by 128 mg, histidine – by 57 mg, leucine – by 176 mg, isoleucine – by 99 mg, threonine – by 83 mg, lysine – by 147 mg, methionine + cystine – by 63 mg, tryptophan – by 27 mg, phenylalanine + tyrosine – by 196 mg. The experimental sample had an increased content of individual minerals compared to the control: calcium – by 9.1 mg, iron – by 308 μg, magnesium – by 11.5 mg, phosphorus – by 32.5 mg, potassium – by 20.9 mg, sodium – by 16 mg, zinc – by 0.13 mg, selenium – by 0.76 mg. Thus, a new technology of boiled sausage with an increased content of complete amino acid composition of total protein and minerals has been developed. The developed boiled sausage will expand the range of meat products for people with an active lifestyle.

REACTIVE EXTRUSION OF POLY(ETHYLENE TEREPHTHALATE): A REVIEW

Sun, 22 Mar 2026 00:00:00 +0200

This review provides a comprehensive analysis of modern scientific and practical approaches to reactive extrusion (REX) of polyethylene terephthalate (PET) - a method that allows integrating the stages of synthesis, modification and processing of the material in a single high-performance technological process. A wide range of chemical agents is considered, including di- and polyepoxides, isocyanates, dianhydrides, bisoxazolines, biscaprolactams and organic phosphites, which act as chain extenders and promoters of chemical modification reactions of PET. The mechanisms of interaction of these reagents with carboxyl and hydroxyl end groups of the polymer, which are formed as a result of its thermal and hydrolytic degradation, are considered in detail. The influence of each type of modifier on the increase in molecular weight, change in melt flow index, rheological characteristics and complex of physicomechanical properties of the material is analyzed. Particular emphasis is placed on the use of structure-forming agents (nucleators) and reactive impact modifiers to optimize the supramolecular structure and overcome the natural brittleness of PET. The work systematizes the literature data and experimental experience of the article authors on the restoration of the properties of secondary PET and formulates recommendations for the selection of optimal systems for obtaining high-quality polymer matrices for engineering plastics and polymer composite materials based on them.

THE RESEARCH OF WASTEWATER IMPACT ON CONCRETE STRUCTURES IN THE SEWERAGE SYSTEM OF A PHARMACEUTICAL ENTERPRISE

Sun, 22 Mar 2026 00:00:00 +0200

The relevance of the study is to determine the chemical composition of wastewater and its impact on the technical condition of the sewage system. Aim. The aim of the work was to investigate the chemical composition of wastewater and its effect on reinforced concrete structures of the sewage system. Methods. X-ray diffractometric, colorimetric, fluorimetric, gravimetric, titrimetric. Results. The study of the chemical composition of wastewater showed a shift in pH to the alkaline side, the suspension of dry substances in water was above the norm in the fourth sample by 5.3 %, in the fifth – by 36.3 %; the dry residue in the first sample by 31.3 %, in the second – by 20.2 %, in the third – by 13.9 %, in the fourth – by 9.3 % and in the fifth – by 27.4 %. The content of ammonium nitrogen was higher in the fourth experimental sample by 52.3 %, and in the fifth by 54.1 %. The level of nitrite ions in the first sample was higher by 9.1 %, in the second by 6.0 %, in the third and fifth by 42.4 %, and in the fourth by 36.4 %; the increase in nitrate ions in the first sample was by 11.1 %, in the second by 21.6 %, in the third by 16.0 %, in the fourth by 19.5 %, and in the fifth by 22.4 %. Conclusions. The implemented measures to reduce wastewater pollution were effective and reduced the load on concrete sewage structures. The scientific novelty of the results obtained lies in the field study of wastewater from a settling well of a pharmaceutical enterprise before and after preventive measures.

COMPREHENSIVE EVALUATION OF ULTRAVIOLET DISINFECTION SYSTEMS CONSIDERING MAINTENANCE, SPECTRAL, AND OPERATIONAL COEFFICIENTS

Sun, 22 Mar 2026 00:00:00 +0200

The paper presents a comprehensive evaluation of ultraviolet (UV) disinfection systems by integrating maintenance, spectral, and operational coefficients into a unified analytical model. The study addresses the progressive decline in UV radiation efficiency caused by lamp aging, surface contamination, and changes in the reflective properties of operating environments. The proposed methodology extends the classical Maintenance Factor (MF) model defined in CIE standards by incorporating additional coefficients that account for spectral effectiveness (SEF), temperature influence (TCF), ballast performance (BF), irradiation geometry (UF), and dose compliance (DCF). Experimental data obtained for various UV systems (TUV15WG13, HNS15G13, TUV36WG13, ZW20D15Y, ZW20D15W) demonstrated that overall system efficiency decreases to 27–36 % of the initial level after 6,000 operating hours. The dominant loss factors were identified as UF (17–38 %), RFMF (20–35 %), and LMF (18–28 %), while RSMF, TCF, and BF contributed minor yet consistent effects. The developed integrated approach provides a more accurate prediction of degradation processes, allowing preventive maintenance scheduling, optimization of energy consumption, and stable disinfection efficiency throughout the service life of UV systems.

EFFECT Of OH-/M2+ RATIO ON THE PROPERTIES OF Fe/CoFe2O4 COMPOSITES OBTAINED BY HYDROTHERMAL METHOD

Liliya A. Frolova, Dmytro Yu. Saltykov, Iryna V. Sknar — Sun, 22 Mar 2026 00:00:00 +0200

Nanodisperse composites were synthesized by hydrothermal method at elevated pressure. To study the influence of OH^-/M²⁺ concentration ratio on phase composition, degree of crystallinity, average crystallite size, magnetic and absorption properties of Fe/CoFe₂O₄ composites, a series of Fe/CoFe₂O₄ composites was obtained by varying synthesis conditions. The obtained composites were characterized by X-ray diffraction, scanning electron microscopy, vibrational magnetometry and microwave analysis. A larger excess of precipitant leads to a higher degree of crystallinity and a larger average crystallite size of CoFe₂O₄. With an increase in the [OH^– /Me²⁺] ratio, the diffraction peaks significantly increase in sharpness and intensity, indicating the formation of crystals with higher crystallinity and average crystallite size. Noticeable shifts in the positions of the diffraction peaks are also found for all samples, while the value of the crystal lattice constant decreases (8.3901–8.3699 Å). Studies using vibrational magnetometry have shown that the dependence of the saturation magnetization (M_s) correlates with the a-Fe content. The maximum values of the saturation magnetization of 200 Emu/g and the coercive force of 900 Oe correspond to a ratio of OH^-/M²⁺ concentrations equal to 4.6. All obtained samples effectively absorb electromagnetic radiation in the range of 8–10 GHz.

BIOCHEMICAL, FUNCTIONAL, AND TECHNOLOGICAL EVALUATION OF WILD BOAR MEAT PREPARED BY DIFFERENT CULINARY METHODS

Sun, 22 Mar 2026 00:00:00 +0200

Aim. The purpose of the work is to study the functional, technological, and culinary properties of wild boar meat and to establish the influence of different heat treatment methods on sensory parameters and product yield. Methods. The study focused on wild boar meat obtained through traditional hunting in the hunting grounds of the Sumy region, Ukraine. Results. The protein content was 21.56–22.68 %, fat – 2.25–2.64 %, which affected the energy value of the meat: 112–118 kcal/100 g. It was found that the meat of female wild boars under the age of one year has a slightly lower nutritional value (112 kcal/100 g) compared to the meat of males, which is due to the lower protein and fat content and higher moisture content. When comparing the functional and technological parameters of raw meat between male and female wild boar, no significant differences were found, indicating a lack of special strategies for processing or marketing meat of animals of different sexes. Cooking wild boar meat by frying (180 °C for 5–10 min) proved to be the most effective heat treatment method for preserving optimal quality characteristics, particularly in terms of sensory and textural characteristics preferred by consumers. Conclusion. Based on the results of the study of the functional, technological, and culinary properties of wild boar meat of both sexes and the establishment of the influence of various heat treatment methods on sensory indicators and losses during cooking, it can be concluded that wild boar meat has high nutritional value, sufficient functional indicators, and has a favorable sensory assessment during culinary processing.

QUALIFICATION SYSTEM FOR COMPREHENSIVE IDENTIFICATION OF HOP OIL

Sun, 22 Mar 2026 00:00:00 +0200

Modern technological capabilities are causing concern due to the creativity of approaches to the falsification of food products and their components, in particular essential oils. The struggle for quality and safety of end products calls on the global scientific community to improve and create more diverse methodologies with mandatory mathematical comparative analysis of the impact on the same system under changing influencing factors. The aim of the research was to create additional criteria for preventing falsification through spectrophotometric analysis of the intensity of light absorption by ethanol solutions of essential oils of bitter hops. Individual graphical-positional anomalies of wavelengths and spectral intervals were determined, and equations of functions of changes in the concentration of terpene complexes in the studied samples were calculated, coefficients were determined, and the error values were experimentally proven. A rational ratio (oil-ethanol) for dissolution without opalescence was empirically established. The spectra and changes in the optical density of hop oil were evaluated in basic units of light absorption and in percentages in the wavelength range from 190 nm to 900 nm discretely, with a wavelength determination step of 0.05–1 nm. Based on the study of known-quality samples, a wavelength range of 456–780 nm was established, at which the fluctuation in the intensity of the absorbing activity of the main terpenoid compounds facilitates the authentication of other samples of ethanol solutions of hop oils. In addition, fluctuations in the coefficients of mathematical systems for monitoring changes in light absorption intensity in ethanol solutions of hop oil provide an opportunity for comparative control of these changes and, accordingly, create additional criteria for preventing counterfeiting.

SYNTHESIS OF A BIFUNCTIONAL CATALYST BASED ON REGENERATED Al₂O₃ ADSORBENT

Sun, 22 Mar 2026 00:00:00 +0200

To synthesize a bifunctional catalyst on an Al₂O₃ support, the initially used adsorbent Al₂O₃ was regenerated at 600 °C for 360 minutes in the absence of atmospheric oxygen. A process model for synthesizing bifunctional catalysts on regenerated Al₂O₃ support was developed using Ni, Co, Mo, and P precursors. According to the elemental composition analysis of the regenerated adsorbent by XRF (X-ray fluorescence) method, it was determined to consist of 81.5 % Al₂O₃. Using the regenerated Al₂O₃ as the support, (NH₄)₆Mo₇O₂₄·4H₂O, Ni A process model was developed to synthesize a bifunctional catalyst using salts such as Ni(NO₃)₂·6H₂O, Co(NO₃)₂·6H₂O, and H₃PO₄ acid, and based on this model, three types of catalyst samples were synthesized. To determine the morphological changes and textural properties of the surface of the obtained catalyst samples, analyses were performed using SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), and BET (Brunauer-Emmett-Teller) model-based methods. These analyses were applied to evaluate morphological changes and textural characteristics of the prepared catalyst samples.

OPTIMIZATION OF INFRARED-CONVECTIVE DRYING MODES FOR APPLES CONSIDERING MOISTURE REMOVAL KINETICS, ENERGY CONSUMPTION, AND VITAMIN «C» PRESERVATION

Sun, 22 Mar 2026 00:00:00 +0200

The object of the study is the process of infrared –convective drying of medium-ripeness «Golden Delicious» apples. The relevant problem was to determine the optimal drying modes that ensure efficient moisture removal with minimal energy consumption while preserving bioactive components, particularly vitamin C. The experiment used slices 3.5 mm thick; drying was carried out at temperatures of 50, 60, and 70 °C and an air velocity of 3 m/s, achieving a final moisture content of 10 %. The mass of removed water, specific energy consumption (SEC = 71.78–110.35 kWh/kg water), average system power (2.78 kW), and the characteristic internal diffusion time (τ≈51 min) were determined. The kinetics of vitamin C degradation was modeled as a first-order process: losses amounted to 20 % at 50 °C, 30 % at 60 °C, and 40 % at 70 °C, which allowed calculating the degradation rate constants k_vit_C. Statistical analysis showed a high correlation between temperature and drying parameters (r≈0.995–0.998), and the constructed regression and exponential models adequately describe the experimental data (R²≈0.998). The obtained results are explained by intensified mass and heat-mass transfer at higher temperatures and the corresponding acceleration of thermolabile component degradation. A distinctive feature of the study is its comprehensive approach, simultaneously accounting for drying kinetics, process energetics, and changes in the biochemical composition of the product, enabling optimization of the mode to obtain high-quality dried fruit. The practical application of the results covers industrial and laboratory infrared drying of apples and similar fruits, where balancing drying rate and vitamin preservation is required, and the developed models allow predicting the energy and quality characteristics of the product.

INFLUENCE OF RIP-ENING TIME ON THE FATTY ACIDS PROFILE AND LIPID QUALITY OF SOFT CHEESES MADE FROM UNPASTEURISED GOAT`S MILK

Sun, 22 Mar 2026 00:00:00 +0200

Expanding the range of artisanal soft cheeses made from unpasteurised goat's milk on the food market meets consumer demand for healthy nutrition and requires the development of criteria for assessing their quality, biological value, age, and authenticity. This involves determining the dynamics of their fatty acid composition and the quality of milk fat during the ripening process. The experiment used artisanal brine Feta cheese with a ripening period of 30 months and artisanal Chevre cheese with white noble mould with a ripening period of 40 days, made at one of the eco-enterprises of the Kyiv region (Ukraine). The study was conducted from May 2022 to December 2024 using gas chromatography. 15 fatty acids were detected in Feta and Chevre cheeses, of which 11 were saturated and 4 were unsaturated. The basis of saturated fatty acids in Chevre and Feta cheeses was palmitic, stearic, capric, and myristic. The proportion of oleic acid in Feta cheese was inversely correlated with the ripening period (r = –0.920 ± 0.074, P < 0.001). The value of ω3/ω6 PUFA during the ripening period varied for Feta cheese within the range of 1 : 4.96–5.74 and for Chevre cheese – 1 : 4.47–43.16. A distinctive feature of Chevre cheese was an increase in the content of linolenic acid by 0.88–0.94% and linoleic acid by 0.73–1.21% on the 40th day of ripening. According to fat quality indicators, Feta cheese was characterized by the highest dietary properties from the 7th day to the 18th month of ripening, and cheese Chevre - on the 40th day of ripening. The fatty acid profile of artisanal goat cheeses Feta and Chevre can be used as one of the criteria for assessing their age and authenticity in combination with physicochemical and microbiological indicators.

DEPOLYMERIZATION OF RIGID POLYURETHANE WASTE VIA CATALYTIC GLYCOLYSIS IN THE PRESENCE OF K, Na, AND Ca COMPOUNDS

Sun, 22 Mar 2026 00:00:00 +0200

The process of chemical recycling of rigid polyurethane waste via catalytic glycolysis with diethylene glycol (DEG) was investigated. The purpose of this work was to study the influence of the nature of some alkaline earth compounds as homogeneous catalysts on the depolymerization of PU into a so-called recycled polyol with properties suitable for further application. The glycolysis process was carried out at a temperature of 220 °C for 40 min. with a mass ratio of polyurethane (PU) waste to DEG of 1 : 2.5. The K-, Na-, and Ca acetates and K carbonate, as homogeneous catalysts at constant mass concentrations (0.2 %, 0.4 %, and 0.6 %), were used. The effectiveness of depolymerization was evaluated by the physical and chemical properties of the obtained liquid products (i.e., recycled polyol), namely by hydroxyl-, acid-, and amine-number as well as by dynamic viscosity. It was found that the studied catalysts significantly intensify the depolymerization process compared to the non-catalytic reaction. Potassium carbonate at a concentration of 0.4 % allowed to obtain recycled polyol with a high hydroxyl number. The obtained results confirm the feasibility of K and Na acetates and carbonates for controlled depolymerization of solid PU waste.

IMMOBILIZATION OF BIOACTIVE COMPOUNDS IN XANTHAN-BASED HYDROGELS: MECHANISMS, PRACTICAL APPROACHES AND CONCEPTS FOR THE DEVELOPMENT OF INNOVATIVE MATERIALS

Sun, 22 Mar 2026 00:00:00 +0200

Immobilization of Bioactive Compounds in Xanthan-Based Hydrogels: Mechanisms, Practical Approaches and Concepts for the Development of Innovative Materials

ATOMIC ABSORPTION AND ATOMIC EMISSION WITH INDUCTIVELY COUPLED PLASMA DETERMINATION OF COPPER, ZINC, NICKEL IN PHARMACEUTICAL SUBSTANCES

Sun, 22 Mar 2026 00:00:00 +0200

The influence of nonionic surfactant Triton X-100 on the analytical signal in atomic absorption determination of copper, zinc, and nickel in pharmaceutical substances was investigated. The sensitivity and precision of analyte determination were increased by using Triton X-100 (w = 4 %) solutions, calibration solutions based on metal acetylacetonates, and treating the analyzed samples with ultrasound for 20 min. The sensitivity of atomic absorption determination of copper increases by 1.80 times, zinc by 1.60 times, and nickel by 1.70 times. The content of analytes in multicomponent samples was determined by atomic absorption and atomic emission spectrometry with inductively coupled plasma. The results obtained by two independent methods were compared using F- and t-criteria. It was shown that there is no significant discrepancy in these results, the difference is insignificant and is due to random statistical error. The accuracy of the analysis results was verified by varying the sample weight and using the “added-found” method. The detection limit for copper (C_min = 0.002 μg/ml, C_lit = 0.004 μg/ml), zinc (C_min = 0.003 μg/ml, C_lit = 0.004 μg/ml), and nickel (C_min = 0.003 μg/ml, C_lit =0.004 μg/ml) was calculated by atomic absorption method.

HPLC METHOD VALIDATION AND UNCERTAINTY DETERMINATION FOR QUANTIFICATION OF KRESOXIM METHYL FUNGICIDE IN CHILI

Sudha Bharti, Anjana Srivastava, Shishir Tandon, Gajanpal Singh — Sun, 22 Mar 2026 00:00:00 +0200

A simple and efficient multi-residue analytical method was developed and validated for the determination of Kresoxim methyl (KM) fungicide applied on chili crop for controlling of several fungal diseases. The fungicide residues from chili samples were extracted using modified QuEChERS method, followed by analysis through HPLC–UV. Method validation parameters viz. specificity, linearity, matrix effects, LOD, LOQ, recovery, accuracy and precision, robustness and estimation of measurement uncertainty were evaluated. Specificity of the method based on the chromatographic peak purity was observed in the chromatograms of KM, and calibration curve was found to be linear with R²> 0.99. Matrix effect for KM in chili was < ±20 %. The recovery studies were conducted by spiking the samples at three (LOQ, 5LOQ and 10LOQ) concentration levels. The average recovery of KM at all the three concentrations ranged between 84–86 % with percent RSD < 3 %. Measurement uncertainty (MU) can be helpful while deciding the compliance of chili samples against the established MRL. Hence both type A and type B uncertainties were considered for calculation of combined uncertainty (Uc) in the method validation process. The combined uncertainty (Uc) was below 25 % default value which is normally considered satisfactory for nonfatty matrixes (fruit, vegetables, and grain) by many regulatory authorities for enforcement decisions. The proposed method validation for KM in chili was simple, rapid, and cost effective with high accuracy and sensitivity requiring minimum use of organic solvents.

SYNTHESIS AND CHARACTERIZATION OF ZrO₂@Fe₃O₄@TSC MAGNETIC NANOCOMPOSITE FOR SUSTAINABLE REMEDIATION OF HEAVY METAL FROM CONTAMINATED WATER

Sun, 22 Mar 2026 00:00:00 +0200

This study presents the synthesis and characterization of a novel adsorbent composed of iron oxide and zirconium oxide magnetic nanoparticles (ZrO₂@Fe₃O₄ MNPs) functionalized with trisodium citrate (TSC). The structural and physicochemical properties of the ZrO₂@Fe₃O₄@TSC nanocomposite were systematically investigated using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The characterization results established that the ZrO₂@Fe₃O₄@TSC nanocomposite shows a spherical morphology with particle sizes ranging from 16 to 20 nm. Magnetic measurements indicated that the nanocomposite possesses ferromagnetic behavior with a saturation magnetization value of 7.71 emu/g. The adsorption narration of the ZrO₂@Fe₃O₄@TSC nanocomposite was evaluated for the removal of Cd (II) ions from aqueous solutions. The adsorption kinetics closely followed the pseudo-second-order model, demonstrating chemisorption as the leading process. The adsorption isotherm data were well described by the Langmuir isotherm model, suggesting monolayer adsorption on a homogenous surface. The maximum adsorption capacity was determined to be 50.26 mg/g at 303 K. These findings highlight the potential of ZrO₂@Fe₃O₄@TSC nanocomposites as efficient adsorbents for heavy metal remediation in wastewater treatment applications.

ACID-BASE AND ELECTROCHEMICAL BEHAVIOR OF “SULFUR DIOXIDE – 1,3,5-TRIS-(2-HYDROXYETHYL)HEXAHYDROTRIAZINE – WATER” SOLUTIONS

Sun, 22 Mar 2026 00:00:00 +0200

Establishing the features of acid-base and electrochemical behavior in “sulfur dioxide – 1,3,5-tris-(2-hydroxyethyl)hexahydrotriazine – water” solutions is undoubtedly an actual and important task. A pH-, redox-, and conductometric studies of protolytic equilibria were carried out for the solutions containing 1,3,5-tris-(2-hydroxyethyl)hexahydrotriazine (TZ; the reaction product of monoethanolamine with formaldehyde interaction), its protonated form (TZH⁺), N-(2-hydroxyethyl)aminomethanesulfonic acid (HEAMSA), and its anion, N-(2-hydroxyethyl)aminomethane-sulfonate (HEAMS) at a constant total content of amine nitrogen 0.1 mol/L with varying content of absorbed sulfur dioxide 0 £ Q_SO₂ £ 0.12 mol/L at temperature range 273–313 K. It was shown that the addition of formaldehyde to solutions of “sulfur dioxide – monoethanolamine – water” leads to a decrease in their pH by 0.09–4.75 units, which is obviuosly caused by the formation of HEAMSA. The symbiotic nature of the change in DpH values with temperature (SO₂ : N < 1.0 : 2.0) is noted at the same content of components in the solutions. Conductometry data indicate the association of free monoethanolamine, its ammonium sulfites and hydrosulfites into less mobile TZ, TZH⁺, HEАМSA and HEAMS^–. Based on the developed mathematical model using pH-metry data, the ion-molecular component composition of “sulfur dioxide – 1,3,5-tris-(2-hydroxyethyl)hexahydrotriazine – water” solutions at 273–313 K was calculated. The concentration dependences on the ionic strength of the solutions were obtained. The concentration constants of TZ protonation and HEAMSA dissociation were estimated. It was shown that under the experimental conditions the thermodynamic dissociation constant of HEAMSA is practically independent on temperature and is equal to 10.14 ± 0.08. The obtained results are recommended to be used in the development of effective chemisorbents of sulfur dioxide.

THERMODYNAMIC PROPERTIES OF 1-[1-(4-METHOXYPHENYL)-2-METHYL-5-PHENYL-PYRROLE-3-YL]ETHANONE SOLUTIONS IN ORGANIC SOLVENTS

Sun, 22 Mar 2026 00:00:00 +0200

Using the Paal-Knorr reaction, 1-[1-(4-methoxyphenyl)-2-methyl-5-phenyl-pyrrole-3-yl]ethanone was produced. The main stages of synthesis and yield of the target compound are described. The temperature dependence of the solubility of the synthesized compound in the temperature range 275.70–299.40 K was investigated experimentally. The use of the gravimetric method for studying solubility at atmospheric pressure in solvents of different classes is described. Using the Van't Hoff equation, the obtained data were converted to standard molar enthalpies and entropies of dissolution. The enthalpy and entropy of fusion of the obtained substance were determined by the differential thermal method. The equations for converting the research results to standard conditions (298.15 K) are given, and the results are used to calculate the thermodynamic parameters of the mixing and dissolution process of the studied ketone compound with organic solvents. The solubility of 1-[1-(4-methoxyphenyl)-2-methyl-5-phenyl-pyrrole-3-yl]ethanone in all solvents increased with increasing temperature, and these data are in good agreement with the literature data for similar substances. The interaction characteristics of the synthesized substance with solvents of different polarity were established, and the dependencies of the thermal effects of dissolution were obtained. This study of the pyrrole derivative 1-[1-(4-methoxyphenyl)-2-methyl-5-phenyl-pyrrole-3-yl]ethanone is aimed at optimizing the synthesis processes of this compound, its further purification and processing for various uses.

GREEN SYNTHESIS OF COPPER OXIDE (CuO) NANOPARTICLES AND THEIR EFFECTS ON THE ELECTRICAL PROPERTIES OF POLYMER COMPOSITES

Seta Azad, Ali K. Mohammed, Zainab J. Sweah, H. N. K. AL-Salman — Sun, 22 Mar 2026 00:00:00 +0200

In this study, metal oxide nanoparticles were obtained using a plant-leaf extract, which was an environmentally friendly synthetic method for obtaining copper oxide nanoparticles as a reducing and stabilizing agent. These nanoparticles were incorporated into various polymer matrices to increase their electrical and anti-microbial performance. The synthesized CuO nanoparticles were structurally and morphologically characterized using FTIR, UV–Vis spectroscopy, SEM, and EDS analyses which shows a spherical structure with an average size of 20–50 nm. Films of polymer nanocomposite were prepared using PVA, CMC, PVP and PE matrices loaded with CuO concentrations (1–7 %). Electrical conductivity measurements show an increase in conductivity with a subsequent maximum of 1.65·10^-4 S/cm for the optimised film, which is due to the efficient dispersion of CuO nanoparticles, i.e., an improved energy pathway. The test with Escherichia coli and Staphylococcus aureus shows the presence of a significant inhibition zone, which indicates strong antibacterial properties of the compound. It is due to the formation of reactive oxygen species. Moreover, they caused a nanoscale interaction with the membrane of the bacteria. In general, the findings indicate that the electrical and biological properties of polymer composites can be greatly enhanced using green-synthesized CuO nanoparticles. Such polymer composites can be used in flexible electronics, antimicrobial coatings, and other applications.

BENZO[f][1,2,4]TRIAZINO[2,3-d][1,4]DIAZEPINES – A NEW HETEROCYCLIC SYSTEM: SYNTHESIS AND SPECTRAL CHARACTERISTICS

Sun, 22 Mar 2026 00:00:00 +0200

Benzodiazepines are an important group of heterocyclic compounds in organic and medicinal chemistry due to their wide range of biological activity and application in medical practice, significant potential for functionalization and synthesis of various compounds with fused cycles. In this work, we present simple methods for the synthesis of a new system of benzo[f]1,2,4]triazino[2,3-d][1,4]diazepines by acylation of of 3-(2-aminophenyl)-6-R-1,2,4-triazine-5(2H)-ones with chloroacetyl chloride. The peculiarities of the reaction, the optimal conditions for the synthesis of the new heterocyclic system, namely the ratio of reagents, solvents, temperature and duration of the reaction, have been established. It has been shown that the starting compounds containing donor-acceptor groups in the reaction in question form a mixture of two structural isomers. An alternative synthetic method has been developed, namely nucleophilic ring expansion of the corresponding 3-R-6-chloromethyl-2H-[1,2,4]triazino[2,3-c]quinazolin-2-ones, and the probable mechanism of this reaction has been discussed. Structural confirmation was achieved using ¹H and ¹³C NMR, LS-MS and X-ray.

SYNTHESIS AND STUDY OF AN ADHESIVE COMPOSITION BASED ON OXALIC ACID, FORMALDEHYDE AND PHTHALIMIDE USING IR, UV SPECTROSCOPY AND DFT CALCULATIONS

Sun, 22 Mar 2026 00:00:00 +0200

Developing environmentally friendly and highly effective adhesive compositions is a pressing challenge in modern materials science. This study synthesized and comprehensively characterized a new adhesive based on oxalic acid, formaldehyde, and phthalimide. These compounds were chosen as starting materials due to their expected adhesive properties and relative environmental friendliness. The resulting sample was analyzed using infrared (IR) and ultraviolet-visible (UV-Vis) spectroscopy to identify characteristic functional groups and intermolecular interactions. Additionally, a quantum-chemical analysis using density functional theory (DFT) was performed to evaluate the electronic structure, chemical bonding characteristics, and molecular stability. IR spectroscopy confirmed the presence of absorption bands corresponding to esterification and amide bonds, while UV-Vis spectroscopy data indicated the formation of conjugated systems that provide structural strength. Theoretical calculations are consistent with experimental observations and confirm the favorable electronic properties of the molecule. A combined experimental and theoretical approach provided a comprehensive understanding of the molecular architecture and potential adhesive properties. Thus, the adhesive based on oxalic acid, formaldehyde, and phthalimide exhibits good adhesion strength and is environmentally friendly to synthesize, making it promising for a wide range of industrial and sustainable applications.

THE QUANTUM-CHEMICAL ASPECTS OF STRUCTURING IN THERMAL CURTIUS REARRANGEMENT MECHANISM FOR SOME ARYL- AS WELL AS HETARYLACYL AZIDES: INFLUENCE OF ACID-CATALYTIC AND SOLVATION EFFECTS OF MEDIUM

Andrey V. Tokar, Olga P. Chigvintseva — Sun, 22 Mar 2026 00:00:00 +0200

Using ab initio density functional method at the PBE1PBE/6-31G(d,p) level of theory, the features of the tautomeric equilibrium of open syn-forms for some aryl- as well as hetarylacyl azides have been investigated, which turned out to be more stable than the corresponding cyclic forms containing an oxatriazole fragment. Further analysis of individual sections for the thermal Curtius rearrangement potential energy surfaces using the model compound 2,6-dimethylpyridine-3,5-diacyl diazide as an example demonstrated the presence of a reaction pathway corresponding to the stepwise transformation of the syn,syn-form for the starting compound into the corresponding diisocyanate as the final reaction product. In this case, the sequential transformation of both acyl azide groups has been accompanied by intramolecular migration of the hetaryl fragment with simultaneous cleavage of the nitrogen molecule at each of the reaction stages. The results of calculations are in good agreement with data of this type obtained earlier and indicate a low sensitivity of the reaction to structural modifications of the substrate, among which the greatest contribution is made by the manifestations of the "ortho-effect" of methyl substituents in the aromatic fragment of the molecules. The overall increase in the reactivity of the studied systems is also shown under the acid catalysis conditions with simultaneous consideration of nonspecific solvation effects of the benzene solution. This approach allows for the detailed conditions of the target transformation and can be actively used to predict the behavior of related systems within the selected computational approximation.

ANTIMICROBIAL COPOLYMERS FROM PARA-AMINOPYRIDINE METHACRYLATE AND METHYL METHACRYLATE: SYNTHESIS AND STRUCTURE–PROPERTY RELATIONSHIPS

Vusala A. Vahabova, Kazim G. Guliyev, Gunel I. Gurbanli — Sun, 22 Mar 2026 00:00:00 +0200

Functional copolymers based on para-aminopyridine methacrylate (p-APM) and methyl methacrylate (MMA) were synthesized via radical polymerization in benzene at 60 °C using azobisisobutyronitrile as the initiator. The copolymerization parameters determined by the Fineman–Ross method (r₁ = 0.85 ± 0.04, r₂ = 0.45 ± 0.03) indicated a higher reactivity of p-APM, resulting in copolymers enriched in aminopyridine units. IR and ¹H NMR analyses confirmed that polymerization proceeds through the vinyl groups with complete retention of amino and pyridine functionalities in the side chains. Thermogravimetric analysis revealed high thermal stability up to 380 °C, exceeding that of polymethyl methacrylate. Mechanical tests showed enhanced strength (91–95 MPa) and Vica softening temperatures of 148–152 °C, surpassing commercial Plexigum M-272. Antimicrobial activity, evaluated by the agar diffusion method, demonstrated pronounced inhibitory effects against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains. Copolymers containing 89.2 mol% p-APM exhibited the highest antimicrobial efficiency, while moderate activity was observed at lower functional-monomer ratios. The biocidal efficiency correlated with both the content and distribution of p-APM units along the polymer chain. The combination of high thermal stability, mechanical strength, and antimicrobial activity suggests that p-APM–MMA copolymers are promising materials for biomedical coatings, membranes, and polymer systems with controlled antimicrobial properties.

PHENOLYSIS OF 2-(CHLOROMETHYL)OXIRANE IN THE PRESENCE OF TERTIARY AMINES: NUCLEOPHILIC-ELECTROPHILIC INTERACTIONS

Sun, 22 Mar 2026 00:00:00 +0200

The aim of this work is to study the reaction series “4-nitrophenol–2-(chloromethyl)oxirane (epichlorohydrin, ECH)–N,N-dimethylaniline,” nucleophilic-electrophilic interactions in the system to compile a kinetic model of oxiranes phenolysis. The catalytic phenolysis of epichlorohydrin was studied using kinetic methods, along with a similar acidolysis reaction for comparison. The reaction kinetics was studied in ECH excess, which acts simultaneously as substrate and solvent, as well as in its binary mixture with tetrahydrofuran. The kinetic scheme of the reaction was confirmed by studying the structure of the synthesized product using ¹H NMR and gas chromatography–mass spectroscopy. The regiospecificity of ECH phenololysis was concluded. The zero order of the reaction with respect to the nucleophilic reagent and the first order of the reaction with respect to the amine were established. The effect of solvent polarity on the reaction kinetics was examined. The kinetic law of the reaction is the same as for the catalytic acidolysis of epichlorohydrin. The kinetic features of the phenolysis and acidolysis of epichlorohydrin with varying solvent polarity were analyzed. It was confirmed that the initial stage of the reaction – amine quaternization – has an S_N2 character. Nucleophilic-electrophilic interactions in the system were analyzed. The mechanism of nucleophilic opening of the oxirane cycle was described in detail. Regiospecific phenolysis and regioselective acidolysis are described by a single kinetic model that corresponds to the mechanism of transfer of the anion of a nucleophilic reagent by an ion pair.

PERIODIC PROCESSES ON A COPPER ELECTRODE IN CHLORIDE ELECTROLYTES

Vita V. Datsenko, Elina B. Khobotova — Sun, 22 Mar 2026 00:00:00 +0200

The aim of the work was to determine the region of periodic phenomena during currentless and anodic passivation of copper in CuCl₂ solutions and to identify the influence of various factors on the process. Copper dissolution (grade M-99) was studied using the rotating disk electrode method. It is shown that periodic phenomena occur during chemical and anodic dissolution of copper in chloride electrolytes as a result of the formation of CuCl passive film with a certain thickness under conditions of the removal of diffusion limitations through an induction period lasting up to 2 min. An increase in the concentration of Cl⁻-ions causes a shortening of the induction period of oscillations; in highly concentrated NaCl solutions the induction period increases. The oscillations have a sawtooth shape with no homogeneity; the overall process is a superposition of oscillations with different amplitudes. With an increase in the current density to 3000 A/m², sub-oscillations disappear. Over time, the oscillation amplitudes equalize and the potential value stabilizes at the level of the upper amplitude value. An increase in the concentration of chloride ions to a certain value reduces the frequency of oscillations and the value of the stationary potential of the copper electrode at which they occur, prolongs the oscillations in time and reduces their amplitude; an increase in the concentration of Cu(II) ions has the opposite effect on the amplitude value. A rise in temperature increases the frequency and chaotic state of oscillations, reduces their induction period and amplitude, and reduces the concentration limit of Cl⁻-ions above which oscillations do not occur. With an increase in the density of the anode current, the frequency of oscillations increases to a certain value and then stabilizes A mechanism of oscillations is associated with alternation of the processes of formation and dissolution of the passive layer.

INFLUENCE OF MAGNETIC FIELD ALIGNMENT ON HEAT AND MASS TRANSFER IN AN UNSTEADY MHD FLOW WITH RADIATION, CHEMICAL REACTION, AND DUFOUR EFFECTS

Sun, 22 Mar 2026 00:00:00 +0200

This study presents an exact analytical solution for the transient magnetohydrodynamic (MHD) free convection flow of an incompressible, electrically conducting fluid confined between two infinite inclined plates. The analysis incorporates the combined influence of an externally applied magnetic field aligned with the flow, thermal radiation, and chemical reactions. The inclination of the plates introduces a gravitational component that alters buoyancy-driven flow dynamics, adding complexity to heat and mass transfer mechanisms. The investigation focuses on oscillatory flow conditions, which are crucial for modeling time-dependent phenomena in geophysical systems, industrial chemical processes, and thermal management applications. The Lorentz force, generated by the interaction between the magnetic field and fluid motion, is examined to assess its effects on velocity and temperature distributions. Thermal radiation is approximated using the Rosseland model, while a first-order chemical reaction term is included in the species concentration equation. The governing partial differential equations for momentum, energy, and mass transfer are solved analytically under specified initial and boundary conditions. The results demonstrate the significant impact of key parameters, including magnetic field strength, thermal radiation, chemical reaction kinetics, and plate inclination angle, on flow behavior, temperature profiles, and concentration distribution. This research advances the understanding of unsteady MHD convection flows under thermal and chemical influences, offering insights for optimizing high-temperature systems and electromagnetically controlled reactive processes. The findings have potential applications in enhancing industrial cooling systems, chemical reactors, and geophysical flow modeling.