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ESTIMATION OF UNCERTAINTY OF GRADING SAMPLES FOR X-RAY FLUORESCENT DETERMINATION OF RHENIUM CONTENT

 29-38 p.
Abstract
For the development and metrological certification of the procedure for measuring the mass fractions of rhenium in metallurgical samples by the extraction-X-ray fluorescence method, solid-phase samples-emitters were prepared to construct a calibration characteristic. The article evaluates the values of the expanded uncertainty of the emitter samples using the Bayesian approach. The sources of uncertainties associated with the preparation of the standard solution, the preparation of the extractant, the extraction process and the measurement of the analytical signal intensity were identified: the error of a volumetric flask and a pipette; the error in measuring the time and temperature of extraction, the error in the expansion of the volume of the flask at the stage of preparation of solutions, the error in the scales when measuring the mass of the extractant and when measuring the weight of the weighed portion of ammonium perrhenate, the error in measuring the optical density on an X-ray fluorescence spectrometer for the prepared emitter samples, repeatability of the results when measuring the analytical signal - emitters, linearity of the calibration characteristics. A quantitative assessment of each source of uncertainty was made, the contribution to the value of expanded uncertainty of all stages of the process was estimated. It was found that the greatest contribution to the value of the total uncertainty is made by the error associated with the error at the stage of preparation of the extractant and the stage of extraction concentration and extraction of the analyte from the liquid phase to the solid. An equation for calculating the total standard uncertainty is derived. The results obtained can be used in the metrological substantiation of the procedure for performing measurements of the ex-traction-X-ray fluorescence determination of the rhenium content in metallurgical samples.
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INFLUENCE OF PROBIOTICS IN THE COMPOSITION OF FEED SUBSTRATE ON THE AMINO ACID PROFILE OF HERMETIA ILLUCENS LARVES

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 39-47 p.
Abstract
The use of probiotics Bacillus subtilis B-8130 and Bacillus licheniformis B-4162 as part of the feed mixture in the cultivation of larvae of the black soldier fly Hermetia illucens influenced the features of the amino acid profile of the larvae. The greatest impact was caused by B. licheniformis B-4162, which caused a statistically significant decrease in the level of 10 of the 18 essential amino acids, including the sulfur-containing amino acids cystine and methionine. B subtilis B-8130 demonstrated an unreliable tendency to decrease the total amino acid content, but statistically significantly reduced the cystine content compared to the control.
The revealed changes in the amino acid content in the larvae occurred against the background of an increase in their mass compared to the control larva. It is assumed that the decrease in the level of amino acids is associated with their expenditure on the formation of glucose and metabolic energy in a more intensively developing larva on a feed mixture with a probiotic.
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NICKEL IONS ADSORPTION BY THERMOMODIFIED FALLEN LEAVES OF CHESTNUT

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 48-59 p.
Abstract
In recent years, the attention of researchers has been attracted by industrial and agricultural waste, which can be used as sorption materials. A special group is made up of lignocellulose-containing components of woody biomass (leaves, bark, needles, fruits, etc.) and wood processing products (sawdust, shavings, chips, etc.). Advantages of using the latter as reagents for wastewater treatment include simple technique, small processing, good adsorption capacity, selective adsorption of heavy metal ions, low cost, free availability and easy regeneration. Trees foliage attracts attention аmong the components of the woody biomass, it has a large specific surface area and falls annually under the conditions of the Russian Federation, which facilitates its collection and use.
Nickel ions are one of the most toxic pollutants that enter water bodies with industrial wastewater. The infor-mation on the nickel compounds toxic effect on living organisms is briefly presented. In this work, we studied the sorption properties of chestnut fallen leaves (CFL) in relation to nickel ions. The sorption capacity maximum value of the thermally modified CFL at a temperature of 250° C (CFL250) is 1.3 mmol / g for nickel ions. By processing the obtained isotherm within the framework of the Langmuir, Freundlich, BET, Dubinin-Radushkevich sorption models, it was found that the adsorption process is most accurately described by the Langmuir model (R2 = 0.9912). The calculated Gibbs energy is equal to -7.86 kJ / mol, it indicates the occurrence of spontaneous physical adsorption of Ni2 + ions on the CFL250 surface.
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NANOPERFORATION TECHNOLOGY AND FUNCTIONAL PROPERTIES OF COPPER STRUCTURED MATERIALS IN THE PROCESS OF GLUCOSE ANODIC OXIDATION

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 60-69 p.
Abstract
The paper presents an original technology for the synthesis of nanostructured copper electrodes by the method of replicas from metallic aluminum nanomatrices on a pilot high-voltage galvanic installation. The technological scheme used makes it possible to carry out the process of continuous high-voltage microplasma perforation of a metal tape with the formation of nanopores of a given size in the range from 20 to 500 nm at a variable voltage. To study the received replicas, a series of indicator electrodes with a working surface made of replica material was created. Cold rolled copper foil was used as a reference material for the electrode. The visible area of the working surface of the manufactured electrodes was examined using a scanning electron microscope. By the method of cyclic voltammetry, the coefficient of increase in the specific surface area was determined by increasing the peak area corresponding to the reduction of the surface film of copper oxide formed on the surface of the copper electrode in an alkaline medium at positive potentials. For a smooth copper electrode, the surface area was 0.071 mm2. For a nanostructured electrode of the same size, the total surface area was calculated with respect to the ar-eas of current peaks corresponding to the reduction of the surface film of copper (II) oxide on the surface of a mas-sive copper electrode and a nano-porous copper electrode. It was found that the catalytic activity, estimated by the magnitude of the current associated with the oxidation of the model substrate – glucose, is approximately 10 times higher than the increase in activity due to the total surface of copper. The anomalous catalytic effect is discussed from the point of view of increasing the local electric field strength due to the high curvature of the surface of nan-ofibers and from the point of view of changing the conditions of diffusion of the substrate to the electrode surface due to nanostructuring.
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APPLICATION OF ELECTRODIALYSIS FOR PRODUCTION OF MAGNESIUM HYDROXIDE FROM SEA WATER

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 70-83 p.
Abstract
Magnesium hydroxide is an important component of many technological processes, it has found wide application in food, polymer, light industry, while synthetic magnesium hydroxide has a number of advantages over natural, namely, it has a higher decomposition onset temperature, there are no unwanted impurities in the structure product, it has a higher degree of whiteness, as well as the ability to change the specific surface area (activity) and dispersion of particles during synthesis during synthesis. The way of obtaining magnesium hydroxide by membrane methods can be called the most modern and modernized today, membrane technology is attractive for developers and investors: the processes of separation of liquid media proceed at temperatures close to the ambient tem-perature, their flow is controlled and predictable. At the same time, with regard to the production of electrolytes in modern chemical technology, electromembrane processes, in particular, electrodialysis, are widely used. It is pro-posed to use sea water as a raw material - a natural resource with a changing chemical and bacteriological com-position depending on the depth of sampling, temperature, and natural conditions. The technological scheme of production is represented by the main stage (two-stage fractional precipitation in a batch apparatus with a stirrer) and auxiliary equipment (ultrafiltration unit, bipolar electrodialysis unit, reverse osmosis unit, etc.); developed to separate magnesium hydroxide from seawater while simultaneously solving the problem of the implementation of intermediate products, which ensures care for the environment. The developed production of chemical reagents, in particular, magnesium hydroxide, implements the processes of fractional precipitation and electrodialysis. The re-sults of calculating the economic efficiency of the method indicate the quick payback of the project, the low cost of a kilogram of the target product.
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EXTRACTIVE DISTILLATION OF TERNARY MIXTURES WITH TWO BINARY AZEOTROPES

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 84-92 p.
Abstract
The phase equilibrium of the n-butanol – n-butyl acetate – methyl isobutyl ketone system was studied using a computational experiment. To separate the mixture, an extractive distillation in the presence of various solvents: dimethyl sulfoxide, N-methyl-2-pyrrolidone and sulfolane was selected. The calculation of the vapor-liquid equilibrium of derivatives of quaternary systems (original ternary system + separating agent) was carried out and the difference in the change in the relative volatility of azeotrope-forming pairs of components in the presence of different solvents was shown. Two separation flowsheets with different structures were proposed. The columns operation parameters that ensure the production of substances of marketable quality with minimal energy consumption were determined. It was shown that the lowest energy consumption is observed for a flowsheet with dimethyl sulfoxide as the most selective agent.
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PURIFICATION OF WASTE WATER FROM THE PRODUCTION OF LIPID CONCENTRATE OF HERMETIA ILLUCENS GARVES WITH WASTE FROM PROCESSING OF BIOMASS PISUM SATIVUM

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 93-104 p.
Abstract
The possibility of using the crushed biomass of the pods of the common pea (Pisum sativum) as a sorption material for purifying model waters from the production of lipid concentrate from the larvae of the fly of the species Hermetia illucens has been investigated. Information on the composition and amount of lipids and saturated and unsaturated fatty acids in insect larvae is briefly presented. The effect of the particle size of the sorption material on the efficiency of the adsorptive extraction of the lipid concentrate emulsion from the model wastewater was investigated and an increase in the degree of purification with an increase in the dispersion of the dried biomass of pea pods was revealed. The dependence of the efficiency of removal of emulsion particles on the dosage of the sorption material and the time of contact of the latter with the sorbate was also investigated. The optimal pa-rameters of adsorption purification have been determined.
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BIOCHEMICAL CHARACTERISTICS OF SECONDARY OSTEOPOROSIS DEVELOPMENT IN VARIOUS DISEASES

 105-118 p.
Abstract
The problem of secondary osteoporosis in various diseases is becoming a public health problem in all countries of the world, which is associated with the high prevalence of this condition among patients, regardless of gender, with chronic renal failure, in women in the postmenopausal period, as well as among patients with pemphigus complicated by the development of glucocorticoid osteoporosis. In this regard, we conducted a systematic literature search and a study of patients with these diseases in order to identify potential secondary osteoporosis. Literature searches were conducted in PubMed and Google Scholar for the keywords mineral metabolism, secondary osteoporosis, and biochemical characteristics. Based on the analysis of the literature data and the results of our scientific work, it seems possible to conclude that the diseases during treatment in all cases are subject to cor-rection. The patterns of mineral metabolism disorders were revealed, which are characteristic simultaneously for all 3 studied pathologies (violation of calcium and phosphorus parameters).
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FORMATION OF NANOCOMPOSITE CARBON MATERIALS WITH BIMETALLIC NANOPARTICLES FOR AUTONOMOUS ENERGY SOURCES

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 5-12 p.
Abstract
The development of highly efficient autonomous energy sources allows for stable and uninterrupted power supply of physical and chemical processes and industries under various operating modes. Modern technological methods and approaches to the production of nanostructured electrode materials, as well as the elucidation of the features of the mechanisms of electrochemical reactions based on platinum metal nanoparticles make it possible to design control sensors, fuel cells and electrolyzers with increased energy characteristics. Carbon nanotubes used to create nanostructured electrodes in chemical energy converters have high functional properties compared to other matrices and, modified with nanoparticles with a reduced metal content, can increase the electrocatalytically active electrode surface area and achieve maximum fuel cell power parameters. In this work, the formation of bimetallic nanostructured composites with a variable composition on carbon carrier matrices for the construction of electrodes of autonomous current sources was carried out. Single- and multi-wall carbon nanotubes were chosen as substrates. To obtain composites, bimetallic platinum-palladium nanoparticles with different metal ratios were synthesized. The materials were studied by electron microscopy and X-ray phase analysis. As a result, an optimal algorithm, a synthesis method and conditions for creating nanocomposites with minimal particle sizes are established. The molar ratio water:surfactant changing, as well as the ratio of precursor metals, it is possible to obtain bimetallic platinum-palladium nanoparticles up to 12 nm. The data on the influence of the formation metal nanoparticles conditions on their size, shape and distribution over the matrix surface had been obtained. A series of prototypes has been formed for practical use in the design of current sources.
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APPLICATION OF A DYNAMIC FILTRATION UNIT WITH A MODIFIED TITANIUM FILTER FOR ELECTROLYTE PURIFICATION IN A HIGH-VOLTAGE GALVANIC SYSTEM

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 13-21 p.
Abstract
The development of functional nanodisperse materials based on porous template matrices is an urgent problem in the design of new devices in the processes of electrolysis of generation of "green" hydrogen, to increase energy saving of alternative energy sources, highly sensitive sensors for chemical technology, as new catalysts for afterburning automobile exhaust, in micro- and nanoelectronic devices. In this regard, the development of technology for the production of such materials, as well as studies of the relationship between the structure and catalytic properties of nanofilament matrix synthesis materials, seem relevant. A method of dynamic filtration of solutions using self-cleaning filters with continuous high-voltage processing of aluminum template matrices is proposed. Purification of aqueous solutions consists in the deposition of suspended aluminum salts on the working surface of titanium filters modified with an organofluorine component. The undoubted advantage of the proposed approach to the filtration process is the possibility of continuous removal of aluminum salt sediment from both the outer and inner surfaces of modified titanium filters due to a combination of cavitation created by built-in ultrasonic emitters and rotation of filter elements. The rotation of the filter elements allows you to direct the flow of liquid almost perpendicular to the flow passing through the filter. As a result, a tangential filtering mode is implemented, which prevents clogging of the filter. In addition, when the filter elements rotate, a partial transfer of torque to the liquid is carried out, due to which the liquid swirls around the filter elements. The swirling of the liquid causes a centrifugal effect of displacement of aluminum salts from the liquid layers adjacent to the filter elements, preventing clogging of the filter. The proposed filtration method for high-voltage electroplating of an aluminum matrix provides voltage and current density stabilization and the formation of ordered cylindrical nanoscale structures with a high aspect ratio.
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