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Magnesium biodegradable alloys are a promising material for self-dissolving surgical implants. Magnesium is known to be sensitive to electrochemical corrosion due to the galvanic effect between the matrix and particles of secondary phases and inclusions. Another important factor is the pH level. The behavior of certain chemical reactions depends on the pH level, so one can assume that the pH level of a corrosive medium at the material surface is a factor determining what chemical reactions can occur there. Finally, there is evidence that variability of the crystallographic orientation of the grains may be a cause of anisotropy of corrosion properties. The purpose of this work is to reveal the influence of the electrode potential of the microstructural elements, the crystallographic orientation of the grains, and the pH level of the near-surface volume of the corrosion solution on the corrosion process. In the study, sections of 2×1.5 mm were marked on the ZX10 alloy samples, for which maps of the distribution of crystallographic orientations and chemical composition were drawn. To assess the influence of the electrode potential of the particles, the authors carried out a Kelvin probe mapping in the 90×90 µm area. Next, corrosion tests were carried out with video filming of the surface on the marked area. To determine the pH level influence, the solution circulation in the cell was varied. Upon completion of the tests, corrosion products and corrosion damage were examined in detail. According to the results, the pH level in the liquid near-surface micro-volumes has a greater influence than the electrode potential of the particles as it provokes the formation of corrosion products of a different composition, which leads to passivation of the surface areas around the particles. The authors identified two different types of filiform corrosion. For filiform corrosion, a correlation between the corrosion direction and the crystallographic orientation of the grains was established.

The article discusses and analyzes the construction of liquid-jet sulfitators used in the beet sugar industry. The importance of sulfitation treatment in the sugar beet processing and raw cane sugar technology is noted and the main advantages of its use at various technological stages are given, namely, preparation of extractant used for diffusion sucrose extraction out of beet cossettes, thin juice processing, thick juice with B- and C-remelts processing, as well as raw cane sugar remelt processing. The advantages and disadvantages of liquid-jet sulfitators in comparison with other constructions are noted and criteria for their improvement are given. It has been noted that the created ejection, which sucks in the sulphitation gas into the contacting chamber, and the fact that the absorption of sulfur dioxide occurs on a larger surface than in other types of structures the main advantages of liquid-jet sulphitators. The main disadvantages are the short length of the contacting chamber, which is insufficient for ensuring complete absorption of sulfur dioxide, as well as instability of the generated ejection when the productivity changes. This determines the criteria given in the article for the improvement of liquid-jet sulfitators. The description of the developed construction of the sulphitator centrifugal-jet nozzle of sugar production liquids is given, which provides: the stability of the sulphitation gas supply in a wide range of plant productivity; stability of the hydroaerodynamic regime of the system «treated liquid – sulphitation gas» inside the sulphitator; sufficient contact time for complete dissolution in the treated liquid of the sulfur anhydride contained in the sulphitation gas. The advantages of the developed centrifugal-jet sulfitators in comparison with typical liquid-jet sulfitators are noted: ensuring the operation range of 50-120% of the nominal capacity (plant production capacity); significant reduction in the technical sulfur consumption for the sulphur anhydride production, which is used as a reagent for the sulfitation treatment of liquids in beet sugar processing; reduction of harmful emissions into the atmosphere due to 100 % sulfur anhydride dissolution in the treated liquid.

The article focuses on describing mathematical model of a multi-phase flow in antroduodenum and its application for predicting digestive process features, including pH level detection. The suggested sub-model representing antroduodenal area of gastrointestinal tract is being developed within the frameworks of mathematical multilevel model depicting evolution of damage to critical organs and systems under exposure to risk factors. We introduced damages as per three functions (motor, secretory and absorbing one) to several gastrointestinal tract zones (body of stomach, antrum, and duodenum) and to pancreas and liver, into the sub-model. Mathematical problem statement includes records of mass and impulse conservation equations for mixture of liquid incompressible phases; ratios for mass flow intensity vector due to diffusion processes; ratios for mass sources due to reactions, secretion and components absorption, food dissolution, initial and terminal conditions. We obtained numeric experiment results when drinks with various pH level (2.3; 3.5; 7) were consumed; they revealed that anomalous considerable increase in acidity occurred in pyloric opening zone and duodenal cap zone when a drink with pH level equal to 2.3 was consumed. The results presented in this work make a considerable contribution into mathematical modeling development used to describe multiphase flows in biological channels with variable form. We showed that obtained acidity levels in various antroduodenum zones correspond to experimental data given in the works of other researchers. In future the model can be applied to predict risks of duodenum damages evolvement together with detecting areas of their localization under exposure to negative factors.

A laboratory experiments was conducted for the assessment of physiological and biochemical responses of iron dust under the influence of different pH levels (6.5, 5.0, 3.0) and two concentration of iron dust (0.1 mg and 0.6 mg) with two particle size (100 μm and 300 μm) sprayed on the Cicer arietinum L. seed surface for fifteen day exposure. Observation was made on germination percentage and germination rate, vigour index, % phytotoxicity of root and shoot, chlorophyll, sugar, protein and proline content in both treated and control plant. The present results revealed that the seed color changes to brown under iron stress. The lower germination percentage and germination rate gradually decrease with pH of the medium but both the parameters were not significantly affected by the iron dust. Moreover higher % phytotoxicity was observed under all treatments compared to control and also lower values of this parameter were recorded in shoot than root. The reduction trend in chlorophyll and protein content was recorded at low pH but reverse result was recorded for sugar. Moreover highest proline was recorded under highly acidic condition.