Microorganisms take an active part in the processes of microbiologically influenced corrosion, for protection against which bactericides with inhibitory properties are used, which are often toxic compounds. There are many studies of eco-friendly “green” biocides-inhibitors, in particular, based on microbial metabolites. Previously, sulfate-reducing bacteria were isolated from the sulfidogenic microbial community of the soil ferrosphere and identified as Desulfovibrio oryzae NUChC SRB1 and NUChC SRB2. The properties of the mentioned strains of D. oryzae to form biofilms on the surfaces of artificial polymers (polypropylene, polyethyleneterephthalate), in particular, under the influence of Bacillus velezensis NUChC C1 and NUChC C2b, were investigated. The effect of the strains B. velezensis, Streptomyces gardneri strain ChNPU F3 and Streptomyces canus NUChC F3 on the ability of the Peribacillus simplex ChNPU F1 strain isolated from the soil ferrosphere to form biofilms on the glass surface was also investigated. So far, indicators of the processes of microbial corrosion of steel 3 induced by sulfate-reducing bacteria D. oryzae NUChC SRB2 under the influence of B. velezensis NUChC C2b and S. gardneri ChNPU F3 strains have not been investigated, which was the aim of this study. Methods: The agar well diffusion method (for antibacterial properties of the supernatants) was used, along with the crystal violet (for the biomass of the biofilm on the steel) and gravimetric methods (for the corrosion rate). Moderate adhesiveness to steel 3 was established for the D. oryzae by biofilm-forming ability. The presence of a supernatant from cultures of S. gardneri, B. velezensis and their mixture (2:1) did not reduce the biofilm-forming properties of D. oryzae. Compared to the control, a decrease in the corrosion rate was recorded for the variant of the mixture of the studied supernatants of bacterial cultures. This indicates the potential of this mixture for corrosion protection in environments with sulfate-reducing bacteria, which requires further research.

Ultrasonic transducers combine coupling elements such as bolt, piezoelectric disk, back mass, and front mass. The quality and performance of the transducer greatly influence the quality of the ultrasonic weld. The design of a transducer requires good coordination with the design of other components such as bolt, piezoelectric disk, back mass, front mass, and sometimes booster, and horn. There have been many studies presenting how to build models for transducer design. However, there are not many articles presenting the design and simulation of transducers using finite element models. This paper will present a finite element model to simulate the coordination of all the above components. The influence of the interaction creation methods of the elements as well as the influence of the choice of bolt load on the predicted axial resonance frequency. In addition, the model also considers whether the simplification of some factors on the elements in the simulation affects the simulation results. The dynamic properties of the transducer obtained from the simulation model will be verified by experiment. The results show that the choice of host surface and slave surface in the interaction affects the simulation results. Meanwhile, the simplification of some parts also has a significant effect on the simulation results. The results of the calculation of longitudinal resonance frequency from the simulation are compared with the results obtained from the experiment and are very consistent with each other.

Introduction. Among the 5-substituted-6-hydroxy-2,3-diarylpyrimidine-4(3H)-ones derivatives, there are compounds with reported anti-inflammatory activities and analgesic activity. It is known that the pharmacological activity can vary depending on how many pyrimidine rings there are in the molecule. Various reports in the patent and scientific literature have revealed that bis(pyrimidine) derivatives exhibit antitumor and antimicrobial activity. Therefore, the aim of our work was the synthesis of new derivatives of bis(6-hydroxypyrimidin-4(3H)-one) with aromatic linker – 2,2'-(1,4-phenylene)bis(6-hydroxy-5-methyl-3-phenylpyrimidin-4(3H)-one) (1) and 3,3'-(1,4-phenylene)bis(6-hydroxy-5-methyl-2-phenylpyrimidin-4(3H)-one) (2). Proof of structure and assessment of the biological activity were conducted through in silico analysis. Methods. Сompounds 1 and 2 were obtained as a result of the interaction between methylmalonyldichloride and the corresponding carboximidamide in boiling benzene medium for 17 h. The structure of the obtained compounds was reliably proven by ¹Н and ¹³С NMR spectroscopy data. Prediction of biological activity spectra was carried out using web resources: GUSAR, PASS Online, AntiHIV-Pred и CLC Pred. Results and Conclusions. 2,2'-(1,4-phenylene)bis(6-hydroxy-5-methyl-3-phenylpyrimidin-4(3H)-one) and 3,3'-(1,4-phenylene)bis(6-hydroxy-5-methyl-2-phenylpyrimidin-4(3H)-one) were obtained in 36 % и 42 % yields, accordingly. The structure of the obtained compounds was reliably proven by ¹Н and ¹³С NMR spectroscopy data. The biological activity of the synthesized compounds was evaluated in silico, specifically, the acute toxicity and spectrum of pharmacological properties. According to the results of screening, compounds 1 and 2 potentially exhibit antitumor activity against cisplastin-resistant ovarian carcinoma and diffuse large B-cell lymphoma-activated B-cell type, antiviral activity against Dengue virus type 2 and SARS-CoV-2 with a high probability. Also, they can effectively inhibit reverse transcriptase (HIV-1). The predicted values of acute toxicity in rats (LD₅₀) with the intravenous route of administration for compounds 1 and 2 were 314 mg/kg and 309 mg/kg, accordingly, with the oral routes of administration at 1525 mg/kg and 1611 mg/kg, accordingly.

The incapsulation of low-soluble pharmaceutical agents in the β- and γ-cyclodextrin cavity (β-CD, γ-CD) successfully solves the current issues related to bioavailability and dose reduction of a variety of anti-inflammatory drugs. This study is focused on nimesulide (Nim), a nonsteroidal anti-inflammatory drug (NSAID).

The molecular complexation of nim/β-CD and nim/ γ-CD was modelled via the Gaussian 09W computer program using the B3LYP method for DFT calculation. Molecular dynamics simulations of the complexes were performed via the NAMD2 software.

The set of conformations, characterized by lowest potential energy was obtained by Gaussian 09W for the nim/β-CD and nim/ γ-CD molecular systems. The results of calculations indicated a low probability of complexation under the standard conditions. Nimesulide molecule exhibits a steric hindrance, leading to instability of the nim/β-CD complex with minimal bond distances of 1.92Å. At the same time, nim/ γ-CD complex shares a higher stability due to the larger dimensions of the carrier molecule. Conformational analysis indicated a deep minima in the product area of the plot, demonstrating stability of the nim/ γ-CD system.

The stability of the nim/ β -CD complex was studied using molecular dynamics approaches. The simulation with length of 5 ns was performed via the NAMD2 computer program using the CHARMM36 forcefield. The further analysis including visualization and data plotting was comleted by the VMD software (V1.9.4). The idea of hydrophobic–hydrophilic interactions between molecules was confirmed by the obtained data. In addition, lack of dissociation of nim/β-CD complex was observed during the entire period of simulation. Stability of complex was also proved by RMSD trajectories analysis, as the corresponding curves were not drastically deviated.

Obtained data support the idea of complexation and relative stability of complexes. The approaches of computational chemistry in study of supramolecules provide deep insights into complexation and make it possible to evaluate affinity.

For ultrasonic plastic welding, the horn design has a great influence on the quality of the weld. The design requirements are more careful, especially when the welding profile is complex. There have been many results presented on the optimization of the profile for wide-like horns. However, there have not been many studies published on block-like horn, especially block-like horn with complex working surface profile. In this paper, an optimal design for a block-like horn with complex working surface profile used for welding turn signal lights on cars will be presented. The objectives are to achieve maximum vibration uniformity in the working surface. In addition, the vibration amplitude amplification and some other factors are also considered in the process of optimizing the horn design. The integration of three methods: finite element method, response surface methodology, and genetic algorithm is used as an optimization tool for the optimal design. The results show that all the selected design variables have the greatest influence on the amplitude uniformity, while the vibration amplitude amplification is most affected by the slot location. The amplitude uniformity achieved for the optimum block-like horn is 95%, while the amplitude amplification is 2.7. In addition, the frequency separation between the longitudinal frequency and the before and after frequencies are 1340 Hz and 1245 Hz, respectively. The optimal design process presented in this study can be considered as a guidance for block-like horn designs in industry with complex profiles in the working surface.

The production of a cheap industrial protein foaming agent with optimal foaming properties is an important research area. Protein foams based on keratin hydrolysates, obtained by alkaline hydrolysis, have complex properties, The European Union has a number of important international agreements on this subject. The dependence of protein foaming properties on alkali hydrolysis conditions of keratin-containing raw materials allows to optimize the hydrolysis process with the result hydrolysate core component protein foamer. During the work, foaming agents were prepared on the basis of hydrolysates obtained using sodium hydroxide and sodium sulphide at different concentrations in hydrolysing solutions. The evaluation of the foam forming properties obtained in the experiment was carried out on such indicators of foam formation as foam multiplication, volume weight of foam, Foam stability during the regulated time and average rate of reduction of foam resistance.

The analysis of the results of the experiment showed that the quality of the protein foaming agent directly depends on the qualitative and quantitative composition of the hydrolyzing solution when producing a keratin-containing hydrolysate. From the blowing agents obtained in the experiment only some of them corresponded to the established ones and were characterized by high foam resistance in the range of 1.5 hours, which made it possible to select optimal compositions of hydrolyzing solutions for obtaining a blowing agent based on keratin-containing raw materials.

Unmanned aerial vehicle also termed as unarmed aerial vehicles are used for various purposes in and around the environment, such as delivering things, spying the opponents, identification of the aerial images, extinguishing of fire, spraying the agricultural fields etc. As there are multi-functions in a single UAV model, it can be used for various purposes as per the user requirement. The UAV’s are used for because of faster communication of information identified, entry through the critical atmospheres and no harm to humans before entering a collapsed path. In concern with the above discussion an UAV system is designed to classify and transmit information about the atmospheric conditions of the environment to a central controller. The UAV is equipped with advanced sensors that are capable in detecting air pollutants such as: carbon monoxide (CO), carbon dioxide (CO₂), methane (CH₄), ammonia (NH₃), hydrogen sulphide (H₂S), etc,. These sensors present in the UAV model monitor the quality of air time to time, as the UAV navigates through different areas and transmits real-time data regarding the air quality to a central unit; this data includes detailed information on the concentrations of different pollutants. The central unit analyzes the data that are captured by the sensor and checks whether the quality of air meets the atmospheric standards. If the sensed levels of pollutants exceed the thresholds, then the system present in the UAV triggers a warning alert, this alert is communicated to local authorities and the public to take necessary precautions. The developed UAV is furnished with cameras which are used to capture real-time images of the environment and it is processed using the YOLO V3 algorithm. Here YOLO V3 algorithm is defined to identify the context and source of pollution, such as identifying industrial activities, traffic congestion, or natural sources like wildfires.

Finite Element Method (FEM) simulations offer a powerful tool for investigating the process of dielectrophoresis (DEP) to deposit single-walled carbon nanotubes (SWCNTs) on a silicon/silicon dioxide substrate using interdigitated gold electrodes. This study focuses on the precise control and manipulation of SWCNTs by applying the non-uniform electric fields generated by these electrodes. Using FEM, we simulate the electric field distribution and the resulting dielectrophoretic forces that influence SWCNT alignment and deposition. The simulations provide detailed insights into the DEP process's parameters, including electrode geometry, voltage magnitude, frequency of the applied AC field, and the properties of the SWCNTs and substrate. Our results demonstrate the effective deposition of SWCNTs, forming well-defined patterns on the silicon/silicon dioxide substrate. The SWCNTs exhibit unique electrical, mechanical, and thermal properties that make them highly desirable for a wide range of applications. This technique offers significant advantages in terms of precision, reproducibility, and scalability for fabricating nanoscale devices. This research contributes to advancements in nanotechnology applications such as sensors, transistors, and other electronic components by providing a detailed understanding of the DEP mechanism for SWCNTs. The potential for integrating SWCNTs into various electronic and optoelectronic devices is significantly enhanced by these findings, paving the way for future innovations in the field.

Graphene, a two-dimensional carbon material, possesses exceptional properties such as high electron mobility, exceptional strength that surpasses that of steel, chemical resistance, environmental friendliness, and a large specific surface area. In this study, we used the modified Hummer process to produce graphene oxide, which was then applied to an aluminum alloy substrate as a corrosion-resistant coating. The aluminum alloy used in our study is AA2024, which has a wide application in industry and aircraft. The coating layer was characterized by micro-Raman spectroscopy and atomic force microscopy (AFM) before and after the reduction process. Micro-Raman spectroscopy provided information on the degree of reduction and the presence of functional groups in the coating layer. AFM images enabled the study of surface morphology and topography. After the reduction process, achieved by annealing in an argon atmosphere at 140 °C, micro-Raman spectroscopy and AFM microscopy were again used to assess structural and morphological changes. The reduction resulted in the formation of reduced graphene oxide (rGO), which exhibited improved conductivity and stability. The combination of micro-Raman spectroscopy and AFM characterization techniques provided detailed information on the properties and effectiveness of the coating layer. This research contributes to the development of anti-corrosion methods using advanced materials and surface engineering techniques.

In aerospace and automotive engineering, improving impact resistance while maintaining lightweight structures is critical, particularly for shell components. Bio-inspired beetle elytron plates (BEPs) offer promising solutions due to their natural design, providing enhanced mechanical performance under impact conditions [1][2].

This study focuses on end-trabecular beetle elytron plates (EBEPs) and grid beetle elytron plates (GBEPs) fabricated through additive manufacturing with eco-friendly materials. These plates were compared to conventional honeycomb (HPs) and grid plates (GPs) under 10 J impact energy. Dynamic impact tests using a drop hammer system measured peak force and other key indicators.

The results show that EBEP and GBEP significantly outperformed conventional plates, with energy absorption increasing by 7% to 10% and with deformation reduced by over 5%. These designs provided up to 15% more stable impact resistance and around 12% higher mean force retention, demonstrating greater structural integrity under repeated impacts.

The findings highlight the potential of bio-inspired plates for enhancing impact resistance in aerospace and automotive shell components. Our research group has already developed methods to design and fabricate curved beetle elytron plates [3][4], and future studies will focus on low-velocity impact tests to further address the demands of lightweight, high-strength structures.

[1] Song, Y., et al. Extraction and reconstruction of a beetle forewing cross-section point set and its curvature characteristics. Pattern Analysis Applications 25, 77–87 (2022).
[2] Song, Y., et al. Free vibration properties of beetle elytron plate: Composite material, stacked structure and boundary conditions. Mechanics of Materials, 185, 104754 (2023).
[3] Song, Y., et al. Clamping method and mechanical properties of aluminum honeycomb cylindrical curved plates under radial compression. Journal of Sandwich Structures & Materials, 24(8), 2142–2152 (2022).
[4] Song, Y., et al. A novel cylindrical sandwich plate inspired by beetle elytra and its compressive properties. Science China Technological Sciences (2023). https://doi.org/10.1007/s11431-023-2524-7