Automatic Welding, 2023, №01. Journal «AVTOMATICHESKAYA SVARKA» Monthly scientific-technical and production journal. ISSN: 0005-111X, Since 1948. Russian version of «The PATON Welding Journal» Text in Russian, contents and summaries in English. The Journal presents a wide range of scientific-technical and promotion information in the field of technologies, equipment and materials for welding, surfacing, brazing, and deposition of protective coatings.

The Paton Welding Journal, 2022, №03. International Scientific-Technical and Production Journal «The Paton Welding Journal» «The Paton Welding Journal» has been published monthly since 2000 in English, ISSN 0957-798X. «The Paton Welding Journal» is a cover-to-cover English translation of the «Avtomaticheskaya Svarka» (Automatic Welding) journal. The «Avtomaticheskaya Svarka» journal has been published monthly since 1948 in Russian, ISSN 005-111X.

The relevance of the research is caused by the need to create optimal filters, the design and physical principles of which are aimed at slowing down the mudding process, reducing the hydraulic resistance, and, thereby, ensuring a long period of operation. The goal is to design self-cleaning filter constructed in the optimal way in the context of hydrodynamic. The object of the research is the well-tube self-cleaning filter that needs improving fluid flow hydrodynamic parameters through punched holes structure changing. Methods: simulation of fluid flow in the well-tube self-cleaning filter hydrodynamic task using the applicable software pack SolidWorks. Results. The paper describes the design of a particle-retaining borehole self-cleaning filter proposed by the authors and equipped with a system of rotating permanent magnets. The magnetic field created by rotation of the permanent magnets, provides a significant reduction in clogging processes. Further improvement of the design is associated with a decrease in hydraulic resistance, which prevents the pumped liquid from penetrating into the filter cavity. The paper introduces the technique for creating a simulation model to solve the internal hydrodynamic problem of fluid flow in a borehole self-cleaning filter using the SolidWorks application software. Simulation is intended to simulate fluid (water) passage through cylindrical holes in the filter wall in the direction from the outside to the inside. The authors have studied the hydrodynamic effects and the main physical parameters that occur as a result of fluid passing through cylindrical perforations. The performed simulation of the pumped fluid flow in the borehole self-cleaning filter made it possible to establish the optimal drilling pattern for perforation holes in the filter frame and the optimal filter length equal to 0,4 of the formation thickness.

A biotesting procedure that makes it possible to record the changes in the intensities of elastic light scattering, light absorption, and intrinsic photofluorescence of the protein component, as well as the determination of the concentration and structuring coefficients of the genomic component, of the samples with viable unicellular test organisms incubated in a liquid nutrient medium in the presence and absence of various external chemical factors, is described. The results of the analysis of the antibiotic activity of various metal cations with the use of this technique are presented. This technique is much more rapid, objective, and comprehensive for the assessment of the effect on the reproduction rate, metabolic activity, and genome structure of the test organisms from the samples of various products, wastes, etc. than standard visual microbiotesting methods.

Peculiarities of porous silicon layers formation during electrochemical etching of p-type silicon were studied. Principal divisions of pore formation mechanisms in n-type and p-type of silicon were demonstrated.

The described microbiotesting technique provides the recording of pH changes, redox potential, electrical conductivity, optical density, light scattering and luminescence intensities, and other parameters of samples with viable test microorganisms incubated in a liquid nutrient medium in the presence and absence of the tested factors. The results of using this system for the analysis of pro- and antibiotic activity of various oil products, as well as weak electromagnetic fields of the megahertz range, are presented. It has been shown that the proposed technique, compared to the standard methods, yields more detailed and objective information and is less time- and labor-consuming.

Рассмотрены особенности процесса формирования слоёв пористого кремния (ПК) в процессе анодного травления р -Si. Показано принципиальное различие в механизмах образования наноструктурированных слоёв на р - и n -Si.

Features of the formation of porous silicon layers during anodic etching of p-Si were considered. A fundamental difference between the mechanisms of the formation of nanostructured layers on p-and n-Si was shown.

Presented are the results of optimization of technology of automatic submerged-arc welding performed in assembly at construction of bridge spans of steels 10KhSNDA and 15KhSNDA (TU 14-1-5120-2008) under conditions of West-Siberian region.Taking into account local climatic and temperature conditions, the designations of metal structures, principle of steel alloying and thickness of welded sheets it is determined that welding shall be carried out using the modes providing heat input in the limits of 30-35 thou J/cm in two passes, on glass substrate with reduced by 20-30 % height of filling of metal-chemical filler.Necessary toughness and strength of welded joints on this technology is explained by favorable conditions for phase transformations and formation of homogeneous structure in weld metal and HAZ. 9 Ref., 4 Tables, 3 Figures.

The change in the photoluminescence peaks of porous silicon at λ = 640–670 and 540–560 nm at 300 and 77 K, as well as their behavior after low-temperature annealing of the samples at 500°С, has been studied. The change in these peaks correlated with that in the IR spectra. The peak at 640–670 nm has been explained by the existence Si–OH groups on the porous silicon layers and the peak at 540–560 nm, by the photoluminescence of the silicon matrix per se.

Based on main principles of porous silicon (por-Si) formation the research of producing containers for drug delivery systems was launched. Nanoparticles for loading medicine were obtained.

Method for the synthesis of polymeric nanoparticles (NP) with encapsulated daunorubicin (DNR) was developed on the basis of double emulsion solvent evaporation technique using biodegradable poly(lactide-co-glycolide) (PLGA), which is aimed at customization of pharmacokinetic properties of the preparation, enhanced accumulation of DNR in tumor cells and prolongation of its action. The obtained polymer nanoparticles (DNR-PLGA) had average size ranging around 138±36 nm, with zeta-potential of –25.3 mV and the polydispersity index (PDI) of 0.072. The release kinetics of DNR from polymer nanoparticles at pH 7.4 and 5.0 has been studied. In vitro studies showed similar specific activity of DNR- PLGA in K562 and MCF-7 cancer cell lines together with an increase in activity in K562 Adr and MCF-7 Adr cell lines, which are anthracycline resistant, by 1.6 and 3.4 times. The study demonstrated the efficacy of the developed PLGA-based DNR delivery system in the improvement of antitumor effect of DNR, overcoming multidrug resistance in cancer cells, and also in the decrease in nonspecific toxicity of the preparation.

A model of the chemical interaction of Si with the (HF 2 ) – ion was propsoed to explain some experimental data on the formation of porous silicon.

Here we examined the influence of polymyxin B, a lipopeptide antibiotic, on planktonic growth and biofilm of streptomycin-sensitive and streptomycin-resistant isogenic strains of bacteria Methylophilus quaylei on polypropylene and Teflon. Biofilm formation was quantified using crystal violet staining, determined by colony-forming unit and examined by light microscopy. It was found that of bacterial surface hydrophobicity affects the biofilm formation: biofilm formation of Methylophilus quaylei MT strain was better on such hydrophobic materials as Teflon and polypropylene. The minimum inhibitory concentration of polymyxin B for the used strains in planktonic and biofilm form was 1 μg/ml. The sublethal Polymyxin B in the concentration of 0.01 μg/ml stimulates biofilm formation and exhibits antibiofilm properties at the concentration of 0.10 μg/ml. Synergistic effect of polymyxin B and streptomycin on streptomycin-resistant strain M. quaylei SM was found.

Here we examined the influence of polymyxin B, a lipopeptide antibiotic, on planktonic growth and biofilm of streptomycin-sensitive and streptomycin-resistant isogenic strains of bacteria Methylophilus quaylei on polypropylene and Teflon. Biofilm formation was quantified using crystal violet staining, determined by colony-forming unit and examined by light microscopy. It was found that of bacterial surface hydrophobicity affects the biofilm formation: biofilm formation of Methylophilus quaylei MT strain was better on such hydrophobic materials as Teflon and polypropylene. The minimum inhibitory concentration of polymyxin B for the used strains in planktonic and biofilm form was 1 μg/ml. The sublethal Polymyxin B in the concentration of 0.01 μg/ml stimulates biofilm formation and exhibits antibiofilm properties at the concentration of 0.10 μg/ml. Synergistic effect of polymyxin B and streptomycin on streptomycin-resistant strain M. quaylei SM was found.

Исследовано влияние типа проводимости Si на процесс зарождения и образования в нём пор при электрохимическом травлении. Установлено, что различие процессов порообразования в Si n- и р-типов проводимости обусловлено свойствами и природой слоёв, образующихся в начальные времена травления на поверхности Si. На основе представлений о химизме процесса взаимодействия Si с травителем предложен возможный состав образующихся слоёв на поверхности Si.