Journal of Chemistry and Technologies

SYNTHESYNTHESIS OF N-ACYLOXY-1-(DIMETHOXYPHOSPHORYLOXY)BENZIMIDATES FROM N-ACYLOXY-N-CHLOROBENZAMIDES SIS OF N-ACYLOXY-1-(DIMETHOXYPHOSPHORYLOXY)BENZIMIDATES FROM N-ACYLOXY-N-CHLOROBENZAMIDES

2025-03-14T11:45:12+02:00

Aim. The objective of this research was to investigate the potential interaction between N-acyloxy-N-chlorobenzamides and trialkylphosphites, along with the characterization of the resulting products' structures. Methods. Employing techniques such as ¹H, ³¹P and ¹³C NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction, we have proved that the reaction of N-acyloxy-N-chlorobenzamides with trimethylphosphite in diethyl ether produces N-acyloxy-1-(dimethoxyphosphoryloxy)benzimidates. Our research demonstrates that the reaction between N-acyloxy-N-chlorobenzamides and trialkylphosphites offers a novel approach to synthesize Z-N-acyloxy-1-(dialkoxyphosphoryloxy)benzimidates. This discovery unveils a significant chemical transformation of N-acyloxy-N-chlorobenzamides. The structure of N-acyloxy-1-(dimethoxyphosphoryloxy)benzimidates has been confirmed by ¹H, ³¹P and ¹³C NMR spectroscopy, mass spectrometry, and XRD study. The study of the N-(4-nitrobenzoyloxy)-1-(dimethoxyphosphoryloxy)benzimidate structure has revealed that the N-(4-nitrobenzoyloxy)-1-(dimethoxyphosphoryloxy)benzimidate is the Z-isomer, with the dimethoxyphosphoryloxy moiety and the N-4-nitrobenzoyloxy group being cis-oriented to the N=C double bond. The ether moiety and the N=C double bond are coplanar, while the dimethoxyphosphoryl substituent is orthogonal to the plane of the N=C double bond. The interaction of N-acyloxy-N-chlorobenzamides with trimethylphosphite has led to a new synthesis of Z-N-acyloxy-1-(dialkoxyphosphoryloxy)benzimidates. The new chemical properties of N-acyloxy-N-chlorobenzamides have been established. The X-ray study of Z-N-4-nitrobenzoyoxy-1-benzimidate has demonstrated the peculiarities of its structure. Notably, an intriguing phenomenon of nitrogen-to-oxygen migration of the dimethoxyphosphoryl group has been observed.

KINETICS OF GLYCEROL ACETYLATION WITH ACETIC ACID IN THE PRESENCE OF NATURAL ALUMOSILICATES MODIFIED WITH ARENESULFONIC ACID FRAGMENTS

2025-03-06T16:50:56+02:00

The kinetics of glycerol acetylation with acetic acid in the presence of natural aluminosilicates of the domestic deposit modified with arenesulfonic acid fragments, namely: bentonite, clinoptilolite and trepel, were studied. It was found that the selectivity of products depends on nature of catalyst and the reaction conditions, instead, in the presence of samples modified with nitric acid (H-samples), the main product is monoacetin. The main factors that allow regulating the activity of such catalysts and the efficiency of acetylation process are established. For example, the studied reaction refers to the processes of self-catalysis and in this case the molecule of acetic acid appear as a reactant and as a catalyst. The conversion of glycerol reaches 80 % and the main product is monoacetin (>60 %). Therefore, the main function of the catalyst in this reaction is to increase the selectivity of di- and triacetin. Regardless of the catalysts mass fraction, the glycerol conversion doesn´t change (~100 %), but changes depending on the reaction temperature and the mole ratio of reactants. According to their catalytic activity, the studied catalysts can be placed in following order: AS-Bent > AS-Tr > AS-CLI.

SYNTHESIS OF ANTHRACENEDIONE-CONTAINING TRIAZENES AND REVIEW THEIR CHEMICAL AND BIOLOGICAL ACTIVITY

2024-12-15T02:25:54+02:00

Aromatic compounds containing the triazene group (-N=N-N-) have had a profound impact on synthetic organic and medicinal chemistry. However, the chemistry of anthracenedione-containing triazenes has been largely unexplored until recently. This has changed over the past decade, and it has become apparent that anthracenedione-containing triazenes are very interesting compounds with unique reactivity. In this review, we summarize recent developments in this field. The review paper first summarizes the preparation of anthracenedione-containing triazenes and describes the spectrum of their biological activity. The review is devoted to the synthesis of triazenes based on anthraquinone derivatives obtained by diazotization and N-azo coupling reactions according to publications in the SciFinder and Reaxys databases over the past recent years. The starting materials for obtaining -N=N-N- groups in the anthraquinone ring were most often derivatives of aliphatic and aromatic amines. Analysis of literature sources showed that anthracenedione-containing triazenes are relatively unstable and exhibit weak reactivity, entering into cyclocondensation reactions, substitution with methylene-active compounds with the formation of the corresponding hydrazine derivatives and others given in the review. And they have moderate biological activity, which is significantly inferior to the triazenes of the benzene series.

EFFECTS OF pH AND EXTENDED HEATING ON α-diCARBONYL COMPOUNDS PRODUCED IN THE D-GLUCOSE-GLYCINE MODEL SYSTEМ

2025-03-11T12:12:42+02:00

α-Dicarbonyl compounds (α-DCs) are significant markers in the intermediate stage of the Maillard reaction, which not only provide pleasant taste and color, extend shelf life and improve functionality, but also generate a large number of potentially harmful substances that can lead to severe food safety problems and pose significant risks to human health. Therefore, food derivatives of α-DCs are under close attention in food chemistry and medicine. The study of the effects of pH and extended heating on the formation of α-dicarbonyl compounds (α-DCs) in the D-glucose-glycine model system is important for understanding methods to reduce or prevent their development in heat-processed foods. In this study the α-DCs formation were determined based on the changes in UV absorbance at λmax 270–290 nm. The results indicated that in the pH range from 1.0 to 7.0 with increasing heating time the formation of α-DCs occurred most slowly in the pH range from 4.0 to 5.0. In the pH range from 7.0 to 12.0, the slower formation of α-dicarbonyl compounds was observed in the pH range from 7.0 to 10.0. The calculated relative rates of α-DCs formation in the D-glucose-glycine model system are in full agreement with the experimental data. The effect of both heating temperature and time on the formation of α-DCs in the D-glucose-glycine model system at pH 9 was investigated using Raman spectroscopy. The study of the α-DC formation patterns is to find the best and more suitable method for producing a healthy food product with good sensory characteristics.

MORPHOLOGY AND SIZE COMPARISON OF CRYSTALLIZED MATERIALS USING IMAGE-BASED COUNTING TECHNIQUES: CONVENTIONAL VS. SUPERCRITICAL PROCESSES

2025-02-11T10:39:03+02:00

Morphological characterization of aggregates or agglomerates using image analysis is a growing topic of research in a variety of industries, including chemical, environmental, food, and pharmaceuticals. The ultimate features of agglomerates are frequently related to their size and shape distribution, and aggregate morphology can have a considerable impact on the efficiency of industrial operations as well as their health and environmental impacts. Given the significant importance of the crystallized product's shape and size, it is critical to apply technologies that allow for measurement, characterization, and quantification, image analysis in particular. This article attempts to use image analysis to determine the size and kind of aggregates analyzed, which is one of the most active study fields. It is demonstrated that, whereas conventional procedures are best suited for quantitative production jobs, supercritical processes are feasible strategies for producing such materials with recrystallized structure based on morphological range and a specified size distribution. The topic covers image analysis methodologies, aggregate characterization, and the various imaging instruments employed. Furthermore, this study demonstrates experience in managing the supercritical recrystallisation process.

Ag2S-Ga2S3-PbS QUASI-TERNARY SYSTEM

2025-02-06T13:45:31+02:00

Multicomponent chalcogenides of copper and silver are scientifically and practically prospective materials, widely used in microelectronics. Thus, these materials posses unique properties such as optical, electrical, ferroelectric and ion conductivity. One of the urgent problems in the solar energy is the development of easily producable, environmentally friendly materials, capable of efficiently converting solar energy into electricity and other energy types. From this point of view, the search for chalcopyrite-structured compounds, such as AgGaS₂, CuInS₂ and PbInS₂, is of great importance. The synthesis of quaternary alloys was carried out in an evacuated quartz ampoule using pre-synthesized melts and high-purity elements at a temperature of 1100–1400 K. After melting the samples were gradually cooled down to 650–800 K at a rate of 10–15 degrees per hour, and then homogenization was carried out under the condition of 300–400 seconds.The state of equilibrium in the quasi-ternary Ag₂S-Ga₂S₃-PbS system has been studied for the first time using modern methods of physicochemical analysis. The study has found that the four sections of the quasi-ternary system are quasi-binary, and based on them, the quasi-ternary system is triangulated into five pseudo-ternary subsystems. It has been proved that in the ternary system a four-component compound AgPb₂GaS₄is formed and there are limited solubility regions based on the initial components.

GREEN SYNTHESIS OF IRON NANOPARTICLES USING BIO-WASTE EXTRACTS

2025-01-09T21:50:40+02:00

Green synthesis of nanoparticles using naturally occurring biomolecules is an efficient, cost-effective, and eco-friendly procedure. In this study, the synthesis of iron nanoparticles is reported by using aqueous extracts of almond seed skin, grape seeds, and pomegranate peels. These extracts work as reducing, stabilizing, and capping agents. In aqueous extracts of each sample, 0.1 M iron sulfate solution was added drop-wise which turned the color of the solution to black. This indicated the successful synthesis of iron nanoparticles. The synthesized nanoparticles were extracted from their respective colloidal solutions by centrifugation and characterized by suitable characterization techniques including SEM, UV-visible, and FT-IR spectroscopy. UV-visible spectra of iron nanoparticles showed significant differences from the extracts and from the iron sulfate solution. This indicated the successful synthesis of iron nanoparticles and their surface capping with biomolecules. The SEM micrograph revealed that the shape of nanoparticles was spherical; The average sizes of grape seeds extract, almond skins extract, and pomegranate peels extract iron nanoparticles were 72.95±3.28 nm, 79.31±2.37 nm, and 77.19±1.84 nm diameter, respectively. The FT-IR spectroscopic study revealed that the most probable compounds involved in the capping and stabilizing of the nanoparticles are phenols/polyphenols, carboxylic acid derivatives, amino acids, and aliphatic/aromatic amines. These iron nanoparticles coated with biomolecules may be further analyzed for their anti-oxidant and anti-cancer activity.

INVESTІGATІON OF CONDІTІONS FOR OBTAІNІNG AG3SBS4 NANOPARTІCLES ІN VARІOUS ORGANІC SOLVENTS

2024-10-21T15:02:13+03:00

Ag₃SbS₄-nanocrystals were synthesized by solvothermal method in various member solvents (ethylene glycol+polyethylene glycol) and (dimethylformamide+triethenolamine). Optimum conditions for obtaining nanoparticles were determined (molar ratios of the amount of components, volume ratio of the solvent, temperature, time, etc.). The crystal structure, morphology, nano-size and chemical composition of the obtained silver thiostibiate nanostructure were studied using thermogravimetric (TG), X-ray powder diffractometer (XRD), energy dispersion spectroscopy (eds) and transmission electron microscopy (TEM). Using EDX and chemical analysis, the composition was found to correspond to the formula Ag₃SbS₄. The results of the TEM analysis showed that the synthesized Ag₃SbS₄ nanowires have diameters ranging from 150 to 200 nm, while their lengths can reach several micrometers. The dispersion solution of Ag₃SbS₄ nanoparticles was prepared in n-heptane, and the forbidden band width was determined from the absorption spectrum of the solution.

HIRSHFELD SURFACE ANALYSIS OF A MONONUCLEAR PYRAZOLE-CONTAINING COPPER(II) COMPLEX OBTAINED BY OXIDATIVE DISSOLUTION METHOD

2024-09-28T19:44:55+03:00

In this work, a method of oxidative dissolution was used to obtain mononuclear copper(II) complex Cu(С₆H₈N₃O)₂ with 1-carboxamide-3,5-dimethylpyrazole. The variety of techniques were used to identify and characterize the structure of the complex and the ligand, such as IR and NMR spectroscopy, microanalyses, single-crystal X-ray diffraction. Hirshfeld surface analysis was performed to visualize the close intermolecular atomic contacts in the crystal structure of the title compound. It was found that Cu(С₆H₈N₃O)₂ was formed as a result of a multistage process of oxidative dissolution of metallic copper with the participation of air oxygen and ammonium ions. This process leads to the appearance of a sufficient amount of Cu²⁺ ions in the solution, which partially ensures the production of the final compound, as well as the dissolution of zero-valent copper through the formation of intermediate Cu¹⁺ compounds, which are oxidized by air oxygen to form divalent copper compounds. It has also been found that ammonium cyanate is formed in parallel through exchange reactions, which undergo dissociation in acetonitrile solutions, and the resulting HNCO undergoes hydrolysis. The hydrolysis products react with the starting ligand 3,5-dimethyl-1H-pyrazole to form 1-carboxamide-3,5-dimethylpyrazole. This acid then reacts with Cu²⁺ ions to form the final mononuclear complex. Single‐crystal X‐ray diffraction analysis reveals that the title compound crystallizes in the triclinic crystal system, space group P (Z = 2). For the title compound, the most significant contributions to the overall crystal packing are from H···H (47 %), H···O/O···H (19.5 %), H···C/C···H (12.1 %) and H···N/N···H (11.5 %) contacts. According to the Hirshfeld surface analysis, hydrogen bonds (H···H and H···O/O···H) and other close contacts involving hydrogen atoms make the main contribution to intermolecular interactions in the title compound. Two intermolecular NH···O contacts with a length of 2.192 Å are the shortest.

SYNTHESIS OF THIOAMIDE COMPLEX COMPOUNDS OF COPPER(II) AND STUDY OF THEIR MUTUAL TRANSFORMATIONS

2025-01-23T13:36:10+02:00

The paper presents improved methods of the synthesis of thioamides of various substitution RC(=S)NHR' (R = R' = Alk, Ar, Het), which is the promising chelating ligandsfor complexation reaction with some 3d-metals. Coordination compounds of copper(II) of the composition [Cu(НL)₂X₂]₂, [Cu(НL)X₂]₂, [CuL₂]₂, containing neutral or deprotonated molecules of benzimidazole-2-N-(4-methoxyphenyl)carbothioamide (HL) and trichloroacetate anion (Х^–) were synthesized. The dimer di(trichloroacetato)-[benzimidazole-2-N-(4-methoxyphenyl)carbothioamide] copper(II) was obtained by the interaction of thioamide (HL) with copper(II) trichloroacetate and trichloroacetic acid in an alcohol medium. The conditions for the transformation (temperature, time, solvent, pH) of one form of the coordination compound into another [Cu(НL)X₂]₂ ↔ [CuL₂]₂ ↔ [Cu(НL)₂X₂]₂ have been determined. The study showed that the synthesis of such coordination compounds in methanol or water-methanol solutions depends on the acid-base properties of the reaction medium. The composition and structure of the synthesized compounds during the above transformations were investigated by elemental analysis and IR spectroscopy. Thus, the possibility of targeted synthesis of functionally oriented coordination compounds [Cu(HL)₂X₂]₂, [Cu(HL)X₂]₂, [CuL₂]₂ by their mutual transformations has been established.

GREEN SYNTHESIS OF TiO2 NANOPARTICLES: A PROMISING TOOL FOR WASTEWATER TREATMENT

2025-01-10T10:43:46+02:00

Non-biodegradable organic pollutants, such as textile dyes, pose significant risks to human health and the environment. Photocatalysis offers a sustainable and cost-effective solution for degrading these pollutants while simultaneously preventing microbial contamination. This study investigates the photocatalytic and antimicrobial activities of green TiO₂ NPs synthesized using an aqueous extract of Allium sativum (garlic). XRD analysis confirmed the anatase phase with an average crystallite size of 52 nm, while FTIR identified the characteristic Ti-O-Ti vibrational band at 470 cm⁻¹. The NPs exhibited a band gap of 3.05 eV, UV absorbance at 337 nm, and a spherical morphology with slight agglomeration, as observed by FESEM. Antibacterial activity was demonstrated against Streptococcus pneumoniae and Proteus vulgaris, while antifungal activity was observed against Aspergillus niger and Rhizopus sp. Photocatalytic degradation achieved efficiencies of 78 % for Methylene Blue and 91 % for Rose Bengal, with kinetic rate constants of 0.008 min⁻¹ and 0.013 min⁻¹, respectively. These findings highlight the potential of green TiO₂ NPs as a cost-effective approach for environmental remediation and microbial control.

STUDY OF THE MECHANISMS OF THE INITIAL STAGES OF MnO2 FORMATION IN SULPHATE AND ACETATE ELECTROLYTES USING THE RRDE METHOD IN COMPARISON WITH THE RESULTS OF QUANTUM-CHEMICAL CALCULATIONS

2025-05-07T22:18:23+03:00

The formation of selective electrodes with high sensitivity for electrochemical biosensors is one of the most important tasks in the development of such devices. Therefore, understanding the mechanisms of electrochemical formation of MnO₂ as an electrode material is an important factor in the strategy of coating synthesis for the determination of hydrogen peroxide in microquantities. In this article, for the first time, such a mechanism is analysed by comparing RRDE (rotating disk electrode with a ring) measurements with the results of quantum chemical calculations. The investigation was carried out in sulphate solutions with pH 1, pH 2 and pH 3.5. In sulfate electrolytes with pH 1 and pH 2, the mechanism of direct electron transfer has been fixed at the potentials for the initiation of the oxidation reaction of Mn²⁺ particles. The proposed mechanism of oxidation of divalent manganese by active oxygen-containing particles was not recorded. But we do not exclude their influence at more positive potentials. We note the important influence of hydrolysis on the process, which is seen in the difference in RRDE dependences at different pH of solutions. We assume that with an increase in pH to 3.5, Mn³⁺ hydrolyzed complexes attach to the surface and further transformations are associated with oxidation in a dense surface coating. The process occurring in the acetate electrolyte was also investigated. The RRDE method confirmed the assumption of the possibility of disproportionation of Mn³⁺ particles to Mn²⁺ and Mn⁴⁺ in the composition of acetate complexes. SEM photographs of MnO₂ coatings obtained in the studied electrolytes illustrate that the nature of the electrolyte and the pH of the solution affect the structure and morphology of the resulting precipitate.

THE CORROSION BEHAVIOR OF Al5SiFe INTERMETALLIC PHASE

2025-02-28T13:02:04+02:00

The present paper is devoted to the study of corrosion behavior of Al₅SiFe intermetallic phase that frequently present in secondary aluminium alloys. It has been shown that in acidic chloride-containing solutions with pH 0.5–1.5 and 1.5–2.5, the mean weight losses, average corrosion rate, and corrosion depth index were at their maximum and temperature of the corrosive medium has a negligible effect on the corrosion rate. Increasing of corrosion medium`s pH up to neutral values resulted the decreasing of corrosion indicators. The lowest corrosion losses were detected in neutral sodium chloride solutions due to oxygen depolarization in cathodic processes and the presence of a protective film formed by corrosion products. This was confirmed by the presence of a passive region on the anodic potentiodynamic curve obtained as a result of the electrochemical study of the Al₅SiFe intermetallic phase in a 3 % sodium chloride solution. Further increasing of the pH of solutions significantly accelerated the corrosion rate. This acceleration is apparently associated with the local destruction of the protective film by hydroxyl anions.

SYNTHESIS AND STUDY OF PHSYSICO-CHEMICAL PROPERTIES OF OLIGO(POLY)-MER SORBENTS BASED ON UROTROPINE AND CYANURIC ACID

2025-05-09T11:51:43+03:00

This study presents the synthesis and comprehensive physicochemical analysis of novel oligo(poly)mer sorbents derived from urotropine and cyanuric acid. The sorbents were obtained via controlled polycondensation reactions involving urea-formaldehyde systems modified with cyanuric acid, leading to structurally robust and functionally active oligomers. Advanced characterization techniques—including SEM, XRD, IR spectroscopy, and thermal analysis—confirmed the formation of new materials with unique morphology, crystallinity, and thermal stability. The synthesized CA+UFO(III) sorbents demonstrated high sorption efficiency for various 3d-metal ions (Cu²⁺, Ag⁺, Fe²⁺, etc.), with optimal performance in the pH range of 4–6. Results indicated that cyanuric acid not only enhances the reactivity of methylol groups but also stabilizes the oligomer structure, reducing formaldehyde release during storage. These findings highlight the potential application of CA-modified sorbents in environmental remediation and industrial wastewater treatment, offering an effective, tunable, and eco-friendly approach to selective metal ion adsorption.

DRYING OF PROTEIN-CAROTINE-CONTAINING RAW MATERIALS BASED ON CARROT AND FABACEAE

2025-01-16T16:27:55+02:00

The article presents the results of research on the preliminary preparation of protein-carotene-containing raw materials based on carrots and legumes for dehydration and its effect on the physical and chemical properties of the materials studied. The research showed that carrots without pre-treatment lose up to 44 % of carotenoids. The developed blanching regimes for certain types of raw materials made it possible to reduce these losses to 1 2%. The compositions were created by combining beans, peas, and oats at a temperature of 90 °C with carrots in a ratio of 1 part protein raw material or oats to 2 parts carrots before drying. This combination reduces carotenoid losses by 4.4–5.1 %. Energy-efficient drying modes for the studied raw materials have been developed, which depend on the temperature of the heat carrier and the moisture content of the material. This is demonstrated by theoretical calculations of the optimization criterion based on experimental data.. A comparison of the experimental τ_exper and the calculated τ_teor drying duration is presented, which shows that their error does not exceed 5 %. The process duration and drying rate are calculated and a graphical differentiation of generalized curves is presented, showing the difference in the kinetics and dynamics of drying in different parts of the process. Combining the drying curves obtained under different modes into one curve confirms that the generalized drying curve adequately describes the process and does not depend on the drying mode. The kinetics of heat transfer was studied with the determination of the specific heat flux density, which showed that a decrease in the moisture content of the material reduces the heat flux density from 1.4–1.8 to 0.05–0.07 W/m² and confirms the energy efficiency of the selected modes. Determination of the total content of carotenoids made it possible to prove that they are stored better in the compositions than in carrot powder after hygrothermal treatment by 6.3–9.6 %.

PROBIOTIC EMULSIFIED PRODUCTS WITH BIOLOGICALLY ACTIVE COLORFUL ATTRACTANTS

2025-04-28T09:54:50+03:00

The possibility of increasing the biological and consumer properties of traditional emulsified products by using a complex of biologically active compounds of plant raw materials is considered and scientific developments of emulsified products, in particular probiotic direction, are analyzed. Taking into account modern food trends, the fatty acid composition of lipid component of mayonnaise sauce has been adjusted. The analysis of fatty acid composition of different oils and mathematical modeling for their selection by the optimal ratio of polyunsaturated fatty acids (PUFA) ω-6:ω-3 was carried out. It was found that to achieve the recommended nutritional ratio of PUFA ω-6:ω-3 at 10:1, it is necessary to add to sunflower oil a smaller amount of linseed oil than soybean oil, which improves the economic performance of products while increasing the biological value. The list of expedient ingredients - extract of Taraxacum officinale roots and colorful attractants represented by plant pigments of heterocyclic and polyene nature - was substantiated. Based on sensory indicators, the amount of aqueous extract of Taraxacum officinale roots - 30.0 % to mayonnaise sauces - was established, as well as the concentration of polyene pigment (carotene dye) at 3.0 % and heterocyclic compounds (chlorophylls) at 3.5 %. Prebiotic bifidogenic ingredients retained a higher number of bifidobacteria in the developed mayonnaise sauces by a factor of 6.8 for chlorophyll sauce and 8.5 for carotene colorant sauce. Mayonnaise sauces with Taraxacum officinale extract and carotene or chlorophyll colorants show a significant increase in antioxidant activity by 4.9 and 6.0 times compared to the control sample, respectively. The given technological scheme of production of probiotic mayonnaise sauces in vector and machinery representation shows the possibility of their manufacturing on the existing technological lines.

FEATURES OF ELASTOMERIC COMPOSITIONS IN THE PRESENCE OF REGENERATED SUNFLOWER OIL PRODUCTION WASTE AS FILLERS

2025-03-11T18:46:18+02:00

The paper investigates the peculiarities of the properties of elastomeric compositions based on butadiene-α-methylstyrene rubber of the Buna KER 1723 brand in the presence of regenerated sunflower oil production waste in comparison with the equal weight content (20.0 phr) of known mineral fillers. It has been shown that the hydrophobized products under study significantly affect the processibility of rubber compounds, the course of sulfur vulcanization at different temperatures, the level of rheokinetic characteristics, and the density of cross-links of elastomeric compositions. It has been established, that in terms of the rubber reinforcement factor, the spent adsorbent with 37 wt.% of the organic component (diatomite P), regenerated by two-stage washing with dichloroethane and petroleum ether, is superior to a product with 57 wt. % organic component (diatomite D), as well as chalk, but inferior to kaolin. Diatomite P can be recommended for use in industrial rubber formulations.

ASPECTS OF RESEARCH ON PROTEIN COMPOSITION OF CRICKET FLOUR

2025-02-23T14:48:10+02:00

This study presents data on the biological value of wheat and cricket flour, focusing on their amino acid composition and protein digestibility. With rising demand for high-protein foods, alternative sources like insect flour particularly from Acheta domesticus – are gaining attention. Crickets contain 40–75 % protein, 15–40 % fats (including essential fatty acids), and 3–10 % minerals per 100 g of dry matter. Despite consumer resistance to entomophagy, processing insects into flour improves acceptability. The main goal of this study was to evaluate the protein content, amino acid profile, and digestibility of cricket flour compared to wheat flour. Protein content was measured using standard chemical methods, including the Kjeldahl method. Amino acid composition was analysed using high-performance liquid chromatography (HPLC), and digestibility was assessed through amino acid indices, which reflect the body’s ability to utilise proteins. Results show that while wheat flour contains key amino acids, its profile is not fully balanced to meet human nutritional needs. In contrast, cricket flour demonstrates a richer and more balanced amino acid composition, particularly in essential amino acids. Chromatographic analysis confirmed higher amino acid content in cricket flour, supporting its superior biological value. Moreover, cricket flour exhibited higher digestibility than wheat flour, highlighting its potential in dietary applications. In conclusion, cricket flour is a promising alternative protein source due to its balanced amino acid profile, higher digestibility, and greater nutritional value compared to wheat flour.

THE STRUCTURE AND PROPERTIES FEATURES OF CONCRETE DURING EXPLOITATION UNDER CONDITIONS OF ORGANIC OIL INFLUENCE

2025-02-10T11:59:02+02:00

The relevance of the study is to determine the impact of vegetable oil on concrete structures in the case of its long-term action. Currently, the buildings of the agro-industrial complex, built in the 70s and 80s of the 20th century, are used to process sunflower seeds into oil. Aim. To determine the effect of vegetable oil on the physicochemical characteristics of concrete. Methods. The strength of concrete samples was determined by destructive testing depending on the depth of oil penetration; structural changes in concrete were determined by scanning electron microscopy; thermal analysis of concrete samples was performed by thermo-programmed mass spectrometry. Results. It was found that sample №1 was 17 % oiled, with a strength loss of 6 %. Concrete sample №2, with 56 % oiled, lost 19 % of its strength. Sample №3, with 100 % oiled, lost 48 % of its strength. The destruction of the concrete structure was established by electron microscopy. Spores and hyphae of microscopic fungi were detected at a depth of 2 cm from the surface. The study of concrete samples using TPD MS showed that carbon monoxide was intensively released at a temperature of 583 °C from samples 2–0.03 and 3–0.05. CO₂ was released at a temperature of 552 °C with an intensity of 0.1 from sample 2 and 0.18 from sample 3. Carbon was not released from the other samples, which is related to the biochemical corrosion of concrete. Water was released from concrete samples 2–0.8 and 3–0.4 at 100 °C. Conclusions. Correlations have been established between the depth of concrete oil impregnation and the loss of strength due to the weakening of contacts between cement stone and aggregate (crushed stone). The scientific novelty of the results obtained lies in determining the long-term impact of organic oil on the physicochemical characteristics of concrete.

WATER QUALITY CONTROL OF THE ZAPORIZKE (DNIPROVSKE) RESERVOIR USING THE AUTONOMOUS HYDROCHEMICAL STATION “NAYADA-2”

2025-05-21T16:01:07+03:00

The problem of water ecosystem pollution is increasing every year worldwide, and this issue has become even more urgent due to the full-scale military actions on the territory of Ukraine. Monitoring the condition of the Zaporizke (Dniprovske) reservoir is extremely important, as the deterioration of water quality and its sanitary condition can pose risks to both the population and the biota. The aim of the study was to analyze the physicochemical parameters of water in the central section of the Zaporizke (Dniprovske) reservoir, specifically near Monastyrskyi Island, and to assess its suitability for domestic, recreational, and fishery purposes. The research was conducted throughout 2024 near Monastyrskyi Island (Dnipro city). To determine the physicochemical parameters of the water, the stationary station "NAYADA-2" was used. The chemical composition parameters of the water were compared with the regulatory standards for domestic, recreational, and fishery purposes. The study found that most of the physicochemical parameters met the regulatory standards for domestic, recreational, and fishery purposes. However, in the summer months, an exceedance of the chemical oxygen demand (COD_Cr) and a decrease in dissolved oxygen concentration were observed, which is a seasonal phenomenon related to the increase in temperature. Additionally, in August, the maximum concentration of total suspended solids was recorded at 24.6 mg/dm³, which does not meet the regulatory standards for fishery purposes. In the autumn, an exceedance of the BOD₅ (biochemical oxygen demand) values was recorded, which could indicate organic pollution of the water body. Comparing the obtained data with previous studies in 2023, no critical changes were found. According to the study results, the water in the research area met the regulatory standards for domestic, recreational, and fishery purposes for most of the parameters and provides a favorable environment for the existence and reproduction of hydrobionts.

ASSESSMENT OF THE CORROSION IMPACT ON THE SERVICEABILITY OF TANK WAGON BOILERS DESIGNED FOR CHEMICAL CARGO TRANSPORTATION

2025-03-26T13:07:04+02:00

The paper investigates the influence of corrosion processes on the operational reliability of tank car boilers intended to transport chemical cargoes. The main corrosion mechanisms, material characteristics, operating conditions, and the impact of various aggressive environments were analyzed. The study uses a combination of field inspection data from inspection of tank cars, statistical analysis, and thermodynamic modeling based on standard electrode potentials and corrosion rates. The results demonstrate a clear dependence of the intensity of material degradation on the type of chemical cargo. Statistical analysis has shown that after 4 years of operation, 25% of tanks have through damage, and after 6 years, 68% have already been damaged. This indicates the need for timely diagnostics and modernization of corrosion protection. The article also discusses promising protection technologies such as nanomaterial-based coatings, pulsed cathodic protection, and integrated monitoring systems. Practical recommendations for preventing corrosion, optimizing maintenance, and extending the service life of railcars are proposed. The results can be used to enhance the safety and efficiency of transporting hazardous goods.

STUDY OF BENEFICIATION WASTE PROCESSING IRON ORE

2025-05-04T20:57:55+03:00

This paper reviews studies on the processing of iron ore concentration wastes from several samples of Ukrainian ore processing plants. The morphological and chemical composition of the Kryvyi Rih, Ingulets, and Poltava samples was determined. A basic technological scheme for processing these samples is presented. It was found that the Kryvyi Rih waste sample contains 38 % total iron, 20 % silica, and 14 % alumina, while the Inhulets sample contains almost 50 % total iron, 10 % silica, and 8 % alumina, while the Poltava sample contains only 28 % iron, 55 % silica, and 2 % alumina. The effect of gravity beneficiation is most effectively reflected in the Poltava sample, as a result of an increase in Fe content from 28 % to 52 %. It was found that the subsequent magnetic beneficiation of the Poltava sample increases the Fe content from 52 % to 63 %, with a mass yield of 65 %. It was found that the final stage – flotation beneficiation of the Poltava sample increases the Fe content from 63 % to almost 66 %, which makes it possible to use it further.

FEATURES OF PRODUCTION, PROCESSING, LABELING OF POLYMERIC PACKAGING FOR FOOD PRODUCTS

2025-02-11T19:36:58+02:00

Food packaging is a specific type of packaging that requires particularly careful selection of materials, production methods, processing methods and storage conditions. Food packaging should be attractive in appearance, durable and at the same time inexpensive, its main property is the ability to guarantee the safety and quality of food products. Trends in the development of the packaging sector are the improvement of production technologies and the quality of packaging, the reduction of material consumption, and the issue of its environmental friendliness. Food products packaged in polymer packaging are in maximum demand in the consumer market; its use is constantly increasing with the growth of the food industry and the turnover of retail chains. Manufacturers and buyers want to know: what types of polymer materials and packaging exist, for which products what packaging and technologies can be used when using it. Important issues are related to the impact of polymer packaging and its waste on the environment, with its processing technologies, with the creation of new types of polymers with the replacement of naturally non-renewable raw materials with natural components. It is necessary to know the labeling of polymer packaging for its proper use, how to safely store and use it without harming the environment and human health. These relevant issues are considered and summarized in the proposed article.

STUDY OF THE DYNAMICS OF OXIDATION OF VEGETABLE OILS TO PROLONG THE STORAGE

2025-02-27T14:37:42+02:00

Aim. To investigate the oxidation processes of edible vegetable oils: unrefined flaxseed oil, refined high-oleic sunflower oil, and refined traditional sunflower oil. The purpose of the study was to examine and analyze the dynamics of oxidation processes in vegetable oils and their impact on the shelf life of food products containing these oils. Methods. The oxidation of oils was analyzed using the peroxide number indicator, which showed that the ratio of the average rates of peroxide compound accumulation in unrefined flaxseed oil, refined traditional sunflower oil, and refined high-oleic sunflower oil was 54 : 43 : 1, indicating a proportional relationship with their degree of unsaturation. The primary oxidation products formed in the oil are unstable, leading to the formation of new radical compounds and more stable secondary oxidation products. The study included the determination of carbonyl compounds, characterized by the anisidine number. Results. The research revealed an important feature of unrefined flaxseed oil oxidation: the anisidine number increased more rapidly compared to refined traditional and high-oleic sunflower oils. This indicates the relative instability of unrefined flaxseed oil hydroperoxides, which undergo destruction to form carbonyl and other secondary compounds. Due to its high content of polyunsaturated fatty acids, unrefined flaxseed oil is vulnerable to oxidation and mixing it with refined high-oleic sunflower oil can enhance the oxidative stability of food products. Conclusions. The results highlight the importance of considering the dynamics of oxidation processes when selecting vegetable oils for food products and suggest that mixing different types of oils can improve their oxidative stability and the overall stability of food products.

IMPACT OF LOW-TEMPERATURE LONG-TIME PROCESSING ON QUALITY CHARACTERISTICS AND SAFETY OF WHOLE-MUSCLE PORK PRODUCTS

2025-02-27T12:51:19+02:00

The parameters and methods of meat temperature treatment have a significant impact on its quality, biological value and technical and economic characteristics, which is of particular importance for a modern manufacturer. The development of new heat treatment modes for the production of high-quality meat products is a priority direction for the meat processing industry. Aim. Investigation of the use of low-temperature modes of processing meat raw materials on the physicochemical, technological, organoleptic properties and microbiological safety of finished cooked and cooked-smoked pork products. Methods. The developed temperature and time parameters of heat treatment of pork meat were investigated; microbiological and organoleptic studies were conducted, the yield of the finished product was calculated, amino-ammonium nitrogen, residual activity of acid phosphatase, pH and acid number were determined. Results. The developed temperature treatment parameters are sufficient for inactivating the necessary amount of microorganisms and ensuring the safety of the product. The manufactured products do not contain pathogenic and conditionally pathogenic microorganisms, and the total amount of microbiota is at a low level. Products made according to the developed thermal processing modes have significantly lower weight loss and better taste characteristics compared to control samples. The study of residual acid phosphatase activity showed that all samples underwent the necessary thermal treatment and reached culinary readiness. Conclusions. Production of whole-muscle pork products under the developed modes results in less destructive changes in protein and fat components of meat, as well as to less weight loss of the finished product with effective destruction of microorganisms.

PROSPECTS OF USING DLP 3D PRINTING TECHNOLOGY TO PRODUCE MEMBRANE CERAMIC MODULES

2024-12-13T15:15:20+02:00

The ongoing evolution of 3D printing technologies demonstrates considerable potential for the production of porous ceramics, including ceramic matrices. These technologies enable the creation of three-dimensional structures with high complexity and precision from a variety of raw materials. This study assesses the feasibility of utilising DLP 3D printing technology to produce ceramic matrices and membrane holders for the development of ceramic membrane modules. To fabricate ceramic matrices by this method, it was proposed to use natural Ukrainian kaolin as the ceramic component in a photopolymer-based suspension. It was found that increasing the kaolin concentration (from 0–40 wt.%) in the suspension fed for 3D printing leads to an rise in viscosity, and with an increase in temperature at which the kaolin was pretreated prior to suspension preparation (0–600 °C), it decreases. The physicochemical processes occurring during kaolin heating were characterised by thermal analysis, infrared spectroscopy, and low-temperature nitrogen adsorption–desorption. The results demonstrate that heating kaolin above 450 °C triggers dehydroxylation, while heating to 640 °C leads to its transformation into metakaolinite. Consequently, the infrared bands corresponding to structural water disappear, and the specific surface area, determined using the BET model, decreases from 22.8 m²/g to 15.2 m²/g. The reduction in viscosity of the suspension with thermally treated kaolin is likely due to diminished interactions between kaolin particles and the photopolymer resin after structural water removal. Modelling and preparation for 3D printing of ceramic matrices and membrane holders were performed using Autodesk Fusion 360 and the Anycubic Photon Workshop slicing software. The results indicate that the DLP method produced structurally integral ceramic matrices and successfully printed membrane holders. Thus, DLP 3D printing technology offers significant prospects for fabricating tailored ceramic matrices and membrane holders.

THE EFFECT OF HAZELNUT FLOUR ON THE STRUCTURAL AND MECHANICAL PROPERTIES OF DOUGH FOR SHORTBREAD COOKIES

2025-03-24T12:43:51+02:00

The aim of this study was to determine the effect of defatted hazelnut flour on the structural and mechanical properties of dough for shortbread cookies. The test samples were made using hazelnut flour to replace 15, 30 and 45 % of wheat flour with an equivalent amount, adding turmeric powder, as well as partially (30 %) replacing butter with hazelnut flour. These types of flour have different chemical and granular compositions. The quality of wheat and hazelnut flour used to produce shortbread cookies was assessed, and it was found that the moisture content of wheat flour was higher than that of hazelnut flour. The acidity was higher in hazelnut flour. The water-binding capacity of wheat flour was higher than that of hazelnut flour, and the fat-binding capacity was higher in hazelnut flour. The ash content in hazelnut flour was 10 times higher than in wheat flour. The paper establishes the technological parameters of dough mixing and baking. When determining the changes in the dough samples by structural and mechanical properties, it was found that the strength of the experimental samples significantly increased. Thus, in samples with 15; 30 and 45 % hazelnut flour and a 30 % butter replacement, the strength increased by 3.5; 4 and 7 times, respectively, compared to the control sample. When determining the adhesive strength, it was found that in samples with 15 % and 30 % hazelnut flour and 30 % butter replacement, the specific tear strength increased. And in the sample with the addition of 45 % hazelnut flour and a 30 % butter replacement, the adhesive strength of the dough decreased. The optimal ratio of recipe ingredients, namely hazelnut and wheat flour, to provide the necessary technological properties of the dough was recommended.

EFFECT OF PRETREATEFFECT OF PRETREATMENT AND PRESSING METHOD ON OIL YIELD FROM SACHA INCHI SEEDS MENT AND PRESSING METHOD ON OIL YIELD FROM SACHA INCHI SEEDS

2025-04-21T00:30:13+03:00

Sacha inchi seeds contain large amounts of oil and have many applications in food and medicine. The aim of this study was to evaluate the effectiveness of different pressing methods and their parameters on oil recovery efficiency. The results obtained using dehulled seeds pressed by conventional pressing method showed the highest efficiency of 78.35 ± 0.10 % at a pressing capacity of 20 kW and a screw speed of 42 rpm. In hot pressing of roasted seeds at 155 ± 5 °C, the efficiency was 79.37 ± 0.08 % at a pressing capacity of 21 kW and a screw speed of 44 rpm. When the seeds were treated with alkali and cold pressed, the highest oil recovery efficiency was 83.14 ± 0.22 % at a pressing capacity of 19.5 kW and a screw speed of 40 rpm. The oil obtained by all three methods contained saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA), with the omega 3-6-9 fatty acid group accounting for 93.35 to 93.65 % of the total fatty acids, indicating the high quality of the oil. The cold pressing method combined with alkaline treatment provides the highest oil recovery efficiency and has the potential for industrial application compared to other pressing methods.

MODELING OF THE FLOW OF NON-NEWTONIAN FLUIDS USING THE SUPERPOSITION METHOD

2025-02-21T12:02:10+02:00

This paper addresses the challenges of simulating viscoplastic longitudinal and cross-sectional flows of non-Newtonian fluids. A superposition method is proposed to construct higher-dimensional flow fields from lower-dimensional ones, accommodating varying boundary conditions and pressure-dependent rheological parameters. The study details theoretical approaches for modeling non-Newtonian fluid flows in channels with diverse geometries, including moving boundaries and pressure drops at channel edges, considering the functional relationships between key process parameters. It is demonstrated that both longitudinal and cross-sectional flows can be represented as a combination of one-dimensional longitudinal flows of the same type, enabling the description of three-dimensional isothermal flows in rectangular channels and two-dimensional flows in flat channels with varying aspect ratios. The resulting theoretical two- and three-dimensional models of viscous flows in basic channel geometries facilitates the investigation of fundamental process regularities and the determination of optimal macro-kinetic and macro-dynamic flow characteristics for non-Newtonian materials, ultimately aiming to reduce energy consumption and material usage in food processing equipment.

IMPROVED SINGLE-STAGE REFRIGERATION UNITS TO REPLACE TWO-STAGE UNITS

2025-03-24T10:25:21+02:00

The ratio between the condensation pressure and the evaporation pressure of the working fluid in vapor-compressor refrigeration machines increases, the losses during throttling of the liquefied refrigerant and the work of adiabatic vapor compression increase. When this ratio π = ρ_cond / ρ_evap reaches a value of 8, to reduce the specified losses, they switch to a cycle with two-stage compression and intermediate vapor cooling and with double throttling of the liquefied refrigerant. However, such an improvement of vapor-compressor units complicates their operation. Therefore, in practice, single-stage refrigeration units are sometimes used even when π slightly exceeds the specified π value, and this leads to significant losses in the efficiency of the refrigeration cycle. The paper proposes to use improved single-stage refrigeration units as an alternative to two-stage refrigeration units. To verify the feasibility and effectiveness of this idea, a comparison of the efficiency indicators of two possible modifications of single-stage refrigeration units was performed to replace a two-stage one with a compression ratio π equal to 9. The calculations showed that the most effective substitute for two-stage refrigeration units is an improved single-stage unit with isochoric limit (maximum possible) regenerative superheating of steam and a polytropic process of its compression. Less effective, but more structurally simple, is a plant with isobaric superheating of steam. The reduction in the effective power of the compressors in these units relative to the indicator of a two-stage unit with limited regenerative heat exchange is 15 and 5 %, respectively, which means that the costs of electricity and fuel used for its generation are reduced. In addition, the thermal loads on the condensers of such plants are reduced, which means their weight and dimensions are reduced, and, most importantly, thermal pollution of the atmosphere is reduced (by 3 and 1 %, respectively).

NUMERICAL STUDY OF DOUBLE CATTANEO-CHRISTOV DIFFUSION EFFECTS IN MHD 3-DIMENSIONAL CASSON FLUID FLOW PAST AN EXPONENTIALLY STRETCHING SHEET

2024-11-10T08:38:37+02:00

A numerical study of a three-dimensional steady-state flow of a viscous incompressible Casson fluid containing nanofluid particles interacting with a stretching sheet is the primary focus of this work. The equations for concentration and energy include the Cattaneo-Christov double diffusion effects. The Prandtl number plays a crucial role in assessing heat transfer characteristics in fluids. Within nanofluid dynamics, Brownian motion and thermophoresis significantly influence thermal behavior. The Cattaneo-Christov double-diffusion model extends traditional energy and concentration equations by incorporating thermal and solutal relaxation times. Transforming partial differential equations into ordinary differential equations is achieved through appropriate similarity variables. Numerical solutions are obtained using the finite element method to analyze modified governing equations. Graphical representations illustrate the impact of key parameters on velocity, temperature, and concentration profiles. Additionally, computational results evaluate skin friction, Nusselt number, and Sherwood number to quantify heat and mass transfer rates. These insights contribute to advancements in thermal engineering and nanofluid research, offering valuable applications for scientists and engineers working on enhanced heat transfer systems.