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- Modification of structural and mechanical properties of the extrudate by
enrichment with food fibers and lipids
Authors: Ihor Petik; Serhii Stankevych, Volodymyr Panasenko, Kostiantyn Siedykh, Maryna Ponomarova, Olesia Filenko, Iryna Balandina, Anton Ryabev, Svitlana Zolotarova, Viktoriia Novikova
Abstract: The object of the study is the composition of the feed extrudate modified by the addition of dietary fiber and lipid sources. The problem to be solved is the optimization of the structural and mechanical properties of the feed extrudate through the rationalization of the addition of components. Regression models have been developed to accurately predict the ratio of modifying additives that provides the specified water resistance and swelling index. It has been experimentally established that the rational ratio of components – 4.0±0.1 % chicken fat and 6.0±0.2 % wheat bran – provides water resistance of 190.0±7.5 min, swelling index of 55.0±2.1 % and porosity of 60.0±2.2 %. The results are achieved due to the complex interaction between the components, where lipids form a hydrophobic barrier, and dietary fibers create a stable porous matrix, which is confirmed by regression models. Comparative analysis with a commercial analogue (“Roycher™ AQUA Carp Finish”) revealed competitive advantages of the developed extrudate: lower cost (310 USD/t versus 1050 USD/t). Structural and mechanical characteristics of the studied extrudates were similar. This makes the developed composition promising for industrial application. The results obtained are explained by the interaction of the protein-starch matrix with lipids and dietary fibers during extrusion, which is confirmed by statistically significant models. A distinctive feature of the study is a comprehensive approach to rationalizing the composition of the extrudate, which combines technological efficiency with economic feasibility. The extrudate of the developed composition can be used in the production of feed for aquaculture. Further research should be aimed at studying the long-term stability of product properties and adapting the technology to industrial conditions
PubDate: Tue, 17 Jun 2025 00:00:00 +030
- Evaluating of the sudden heat impact on volatile gases release during the
gasification process of weakly grade metamorphized coal
Authors: Аlexandra Аtyaksheva; Anastassiya Dashevskaya, Almagul Mergalimova, Sultan Ybray, Maralgul Aitmagambetova, Ruslan Umirzakov, Zhenis Sultanbek
Abstract: The object of research is a low-temperature gasification technology of weakly grade metamorphized coals. One of the outstanding issues of the low-temperature gasification technology of weakly grade metamorphized coals remains the long processing period due to the coal weak energy activation directly dependent on the release of volatile gases, which depend on isotropic state of coal. The problem that was solved is to scale up coal activation energy through the sudden heat during thermal processing. The results obtained show a shift of the volatile gases release beginning to a temperature of 410°C in the same quantity as with the step-by-step heating to a temperature of 500°C. In addition, the sudden heat contributes to a reduction of CO2 emissions by 12%, indicating an improvement in environmental performance. These results are explained by the fact that a sharp difference in temperatures of 20°C and 400°C creates conditions for the appearance of energy distortion in the isotropic zones of the coal body heating. This energy weakens and destroys the internal bonds between the coal particles and creates conditions for the release of new volatile elements at lower temperatures. The main features of the results obtained, which made it possible to solve the problem studied are the results on transformation of thermal stresses into energy of distortion at the sudden heat in the relationship between the mechanics and physics of anisotropic coal. The scope and conditions of practical use of the results obtained is will allow for the adjustment of gasification techniques for coals with low degree of metamorphism and the establishment of gasification regimes, taking into account the design and capacity of the gasifiers
PubDate: Tue, 17 Jun 2025 00:00:00 +030
- Improving the model for determining the composition of gunpowder gases
during thermal destruction of gunpowder in a limited volume space
Authors: Olexander Brunetkin; Oleksandr Sidelnykov, Maksym Maksymov, Yevhenii Dobrynin
Abstract: The object of this study is a model of the process of formation of products of thermal destruction of nitrocellulose powder at different values of pressure of the mixture of powder gases. The work is aimed at eliminating the uncertainty in the list of powder combustion products. In many cases, the formation of condensed carbon during the shot is not taken into account, which does not correspond to the real process. The process of formation of powder combustion products has been studied both under experimental conditions at a pressure of several MPa, and under shot conditions at a pressure of ~300 MPa and more. The proposed model makes it possible to explain the cause and conditions of condensed carbon formation. The possibility of formation of up to 10 % of condensed carbon from the initial mass of powder during the shot has been shown. An improved model was built using the molar composition of the combustion products. The calculation of the specific volumes of gaseous reaction products with a change in the pressure of the gas mixture was carried out taking into account the change in their compressibility coefficient based on the Peng-Robinson equation. Within the limits of pressure values change during the shot process, the possibility of changing the equilibrium constant values in the range from ~40 % to twofold has been shown. The formation of condensed carbon is explained by the reaction of carbon monoxide disproportionation. The range of values of thermodynamic parameters of powder gases that ensure the possibility of this reaction was identified. The proposed model could be used in the experimental determination of the composition and energy characteristics of a powder sample in the field based on the library method. Given the identified powder composition, the problem of internal ballistics could be solved for the prompt determination of shot parameters
PubDate: Tue, 17 Jun 2025 00:00:00 +030
- Electrolysis and precipitation-based purification of ferronickel for
high-purity nickel production
Authors: Anne Zulfia Syahrial; Vita Astini, Johny Wahyuadi M.S
Abstract: This study investigates the purification of ferronickel through electrolysis and precipitation processes to produce high-purity nickel. Ferronickel has yet to find extensive applications in industries requiring high-purity nickel. So, it is imperative to develop technologies that can upgrade ferronickel through electrolytic processes. Ferronickel, consisting of approximately 18% Ni and 80% Fe, represents an abundant but underutilized resource for high-grade nickel applications. Electrolysis was conducted using ferronickel anodes and graphite cathodes in 2 M HCl, followed by oxidation with H2O2 and precipitation with NaOH under varying pH (4.4 and 4.7) and temperature (40–70°C) conditions. Results demonstrated that the Ni concentration increased linearly from 5.36 g/L to 32.57 g/L over 8 hours of electrolysis, while Fe concentration rapidly increased and stabilized around 84.8 g/L after 3 hours. XRD analysis revealed improved crystallinity at higher temperatures, predominantly forming FeO2 and NiO phases at 70°C. XRF analysis confirmed effective iron removal, achieving 78.91% Fe precipitation at pH 4.4 and 70°C, while nickel recovery was maximized at 14.60% at pH 4.7 and 70°C, but this pH is not favorable due to the Ni loss. SEM indicated finer, more homogeneous precipitate morphology at elevated temperatures. SEM imaging revealed that at pH 4.4 the precipitate formed at 40°C had a coarse, loosely packed structure with large, irregular particles (average size ≈6.50 µm). By contrast, at 70°C the precipitate was much finer and more homogeneous, with particles ~916.8 nm. The findings highlight that electrolysis follow by optimized precipitation enables efficient separation of nickel from iron, offering a promising alternative route for upgrading ferronickel without relying on HPAL or matte processes. This approach contributes to diversifying nickel supply chains and promoting sustainable raw material utilization using local content
PubDate: Tue, 17 Jun 2025 00:00:00 +030
- Estimating the influence of polyorganosiloxanes on the properties of
fire-retardant halogen-free polymer compositions for cable articles
Authors: Volodymyr Zolotaryov; Olena Chulieieva, Taras Antonets
Abstract: The object of this study is the processes of supramolecular structure formation and the thermophysical, rheological, physical-mechanical, and electrophysical properties of halogen-free fire-resistant polymer compositions. Aluminum oxide trihydrate is used as a flame retardant. The effect of the flame-retardant filler becomes noticeable only with a significant filling (60%), when the rheological and operational properties of polymer compositions deteriorate. The use of polyorganosiloxanes makes it possible to reduce the negative impact of the filler on the thermophysical, rheological, physical-mechanical, and electrophysical properties. Therefore, the effective use of polyorganosiloxanes to regulate the properties of fire-resistant polymer compositions is an urgent task under consideration. Fire retardant halogen-free polymer compositions were studied. The content of the flame-retardant filler is 60%. The samples under study additionally contain polyorganosiloxanes, which were used as modifiers for the directed regulation of properties of fire retardant compositions. The effect of polyorganosiloxanes on the formation of the supramolecular structure of filled polymer compositions for cable articles has been established. Due to this, the phase transition temperatures increase by 2–4°C, the temperature of the beginning of decomposition by 12–17°C and the end of decomposition by 5–6°C. The effect of the influence of polyorganosiloxanes with a viscosity of 50–500 Pa·s on a decrease in the melt viscosity of fire retardant polymer compositions from 5.342 to 4.330 Pa·s with an increase in the shear rate from 20 to 60 s-1 has been shown. The results make it possible to use polyorganosiloxanes for targeted regulation of rheological and operational characteristics of fire-resistant polymer compositions for the manufacture of insulation and sheath of power cables
PubDate: Fri, 06 Jun 2025 00:00:00 +030
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Open Access journal
