The results of the investigation of the complexation of Al³⁺ with anthocyanins of red wines (cyanidin-3-O-glucoside and delphinidin-3-O-glucoside) present in the work. By examples of delphinidin-3-O-glucoside and pelargonidine-3-O-glucoside, only dihydroxylated forms of anthocyanins are capable of forming a complex with Al³⁺, while non-hydroxylated anthocyanins of such complexes can not form. In the selected conditions, the total contents of dihydroxylated anthocyanins in wines made from different grape varieties (in terms of cyanidin-3-O-glucoside) are determined, which vary for red wines from 8.7 mg/dm³ for Cabernet Kuban Vine Company to 27.1 mg/dm³ for wine made from the Saperavi grape variety. The greatest contents of these forms of anthocyanins were obtained for wines made from the grape varieties of Saperavi, Krasnostop and Cabernet. To determine the relationship between dihydroxylated anthocyanins and monomeric forms, the total content of monomeric forms of anthocyanins in the investigated wines is determined by the method of pH-differential spectrophotometry. It was found that the share of these forms of anthocyanins in the total content of monomeric forms was 9 – 14 %. Between the total contents of dihydroxylated and monomeric forms of anthocyanins, a high degree of correlation was obtained (r_c = 0.98; r_t = 0.63 for n = 10; α = 0.05). The relationships between the total contents of anthocyanins (both monomeric and dihydroxylated) with spectral characteristics (color intensity and shade) were determined by the recommended IOVV in evaluating the quality of wines. It is shown that for wines with the highest content of dihydroxylated and monomeric forms of anthocyanins, higher color intensities are characteristic.

We developed methods of microwave sample preparation of ferroalloys for subsequent determination of W, Mo, Mn, Si, P, Cu, As, and Sn in ferrotungsten; Si, Ca, Al, and P in silicocalcium and B, Al, Si, Cu and P in a ferroboron using inductively coupled plasma atomic emission spectrometry. The developed methods provide significant shortening of the procedure and increase in the profitability of the analysis. Specified compositions of the acid mixtures for decomposition of ferroalloys and regimes of microwave heating provide complete conversion of the samples into the solution, exclude autoclave leakage and allow determination of all rated elements. Correctness of the determination is confirmed by analysis of standard samples and comparison with the results of the determination in accordance with GOST. The proposed methods shorten the duration of sample preparation to several hours and total time of analysis by 9 – 18 times.

A method of gac (Momordica cochinchinensis) seed oil sample preparation is proposed with allowance for high chemical lability of the compounds containing conjugated C=C-bonds. The method includes extraction at room temperature and purification by solid-phase extraction (SPE), n-hexane being a convenient solvent for oil extraction from seeds and the extract can be directly purified by oil sorption on the syringe (packed)cartridges filled with silica gel. However, before cleaning, it is necessary to verify the absence of catalytic activity of the sorbent towards chemically labile conjugated trienoic compounds. It has been shown that some commercial grades of silica gel can quickly disintegrate the oil. Using the developed method we obtained transparent seed oil with a refractive index of 1.503 typical for highly unsaturated oils, the oil content of seeds being 53%. Data of reversed-phase HPLC revealed the same set of triacylglycerols (TAG) characteristic of another Momordica species bitter melon (M. charantia) and contains di-α-eleostearate-stearate as a main component (47.9 ± 0.5 mol. %), each of triacylglycerol set has isomers wherein the radical of α-eleostearic acid is replaced by radical of α-eleoctearic acid. Fatty acid composition of the oil, calculated from TAG composition contains: 62.1 ± 0.3% eleostearic acids, 11.2 ± 0.3% linoleic, 5.5 ± 0.2% oleic, 1.5 ± 0.2% palmitic and 19.7 ± 0.4% stearic acids.

We report on a fluorimetric determination of synthetic food azo dyes Ponceau 4R (E124) and Carmoisine (azorubine, E122) in soft drinks. Considered azo dyes are one of the most common and dangerous synthetic dyes, often used in children’s drinks to give them attractive red shades. The choice of fluorimetric method of analysis is motivated by high sensitivity, selectivity and total rapidity of the procedure compared to other (spectrophotometric, electrochemical and chromatographic) known methods, thus being rather useful for determination of low content of the substances. Specified working conditions for dye determination in beverages: excitation wavelength of 330 nm and detection interval 350 – 500 nm. Synthetic dyes were analyzed on a «Fluorat-02-Panorama» (Lumex LLC., St. Petersburg) fluid analyzer. The obtained wavelength of azo dye fluorescence (420 nm) is used as a working wavelength for quantitative determination of azo dyes Ponceau 4R and Carmoisine (azorubin) in soft drinks. The reproducibility of the results obtained for two food azo dyes using fluorimetric and spectrophotometric methods of their determination in soft drinks is shown.

In the article the questions connected with current requirements of test laboratories in terms of proficiency test by interlaboratory comparison (comparative) the test (PT) were considered. The comparability of international and Russian approaches in the choice of periodicity and the principle of the formation of a plan for the participation of accredited laboratories in proficiency testing given the scope of the accreditation area, examples of documents of the accreditation bodies international accreditation system ILAC and the national accreditation body of the Federal service for accreditation is shown. Highlighted the importance of PT in the quality control of test results, especially for those laboratories which are involved in study of products exported to various countries, including those which included in the Register of certification bodies and testing laboratories (centers) of the Customs Union carrying out assessment of conformity of products to requirements of technical regulations of the Eurasian economic Union (Customs Union). Attention is drawn to the options for the organization of proficiency testing providers of PT, or of participating laboratories, as well as the possibility of using the results of the comparison in practice of laboratories to assess their competence by accreditation bodies, but also in the everyday practice of quality management and evidence of the effectiveness of the quality management system.

The article describes NSRDS legal basis including summaries of Federal Law «On assurance of measurement uniformity», RF Government Decree «Regulations Concerning National Standard Reference Data Service on Physical Constants and Substances and Material’s Properties», Rosstandart Administrative Order (April, 2016) concerning NSRDS Center, list of Rosstandart normative documents. Together with NSRDS structure and activity areas describe definition of SRD and NSRDS Procedures. The structure of the best SRD System in industry at «ROSATOM» is shown. Results of certification SRD and NSRDS Procedures for last years is presented together with Government Program. Described International (CIS) SRD System and some results of the System activity. Plans for next 10 years NSRDS development in presented.

The necessity of studying the structure of the blade material and corresponding in-service structural changes is attributed, on the one hand, to the fact that the structural changes may impair the performance of the material thus promoting the blade fracture. On the other hand, the structural changes can serve as diagnostic signs in determination of thermo-mechanical conditions of the blade destruction. Moreover, the structural changes in the blade material often determine the service life of the blades: aside of creep mechanism, in-service depletion of the blade lifetime in high temperature gas turbine engines of maneuvering aircrafts is attributed to complex thermo-mechanical loading of the blades which, in turn activates the mechanisms of fatigue and thermo-mechanical fatigue. Monitoring of the structural state of the blade material with equiaxed crystallization (ZhS6U, VZhL12U), directed and monocrystallization (ZhS26, ZhS32) and studying the features of structural changes attributed to the operational vulnerability of the turbine blade material are the main goals of the study. The features of changes in the morphology of the strengthening γ’-phase and carbide transformation in the blade material that occur in-service are considered. The results of monitoring the structural state of the blade material are compared with the results of testing the same samples under laboratory conditions simulating thermo-mechanical loading. Microstructural criteria are recommended for more accurate evaluation of thermo-mechanical conditions of operating vulnerability of the turbine blades of high-temperature aircraft engines.

A promising way for quality diagnosis of socially significant food products is using of the methods based on phenomenon of electrical polarization and/or electromagnetism in a liquid dielectric medium. In this paper, the interrelation between quality features and electrophysical properties of olive oil has been experimentally proved, and a method of thermally activation current spectroscopy has been propose to evaluate the fatty acid composition and degree of oxidative damage. The main oil components — triglycerides of fatty acids and their little stable associates — contain polar functional groups and unsaturated chemical bonds, which are capable for ionizing, polarizing and electric charge transferring. It is shown that thermally conditioned associates disintegration gives an electrophysical response, registered as thermally stimulated current, and the same type of associates disintegrated in certain temperature ranges. The presence or absence of characteristic current peaks can be a diagnostic feature describing the fatty acid composition and oil quality. Thus, thermally activation current spectroscopy is an informative method for analyzing food fats, and its application makes it possible to obtain an integral electrophysical characteristic — the distribution of current peaks on a temperature scale. By the type of spectrum, it is possible to determine oil species or to fix some indistinctive diagnostic features.

The article presents the researchresults on the empirical dependencies ofa carbon-carbon composite material (CCCM) with orthogonal reinforcement (3D) characteristics (specific electrical resistance, thermal conductivity coefficient, dynamic elastic modulus, coefficient of thermal linear expansion, density). The definition of these characteristics was made in accordance with the regulatory documents (GOST and ASTM). Based on the tests and calculations results, a number of formulas were obtained that describe the empirical relationships between the characteristics of the material. According to these formulas it is possible to calculate the value of the sought-for material characteristic from known values of one or several characteristics through the calculated constant for a given relationship. It should be noted that the formulas and graphical dependencies given in the article are valid only for this particular material.

In justifying the applicability of the steels for the manufacture of structures operating at low temperatures various methods of temperature control of viscous-brittle transition are widely used. The most physically reasonable, but also the most time consuming is the method of determining the temperature brittle fracture arrest (T_a), when testing large-scale specimens-plates. In this connection there is a problem to justify the prediction temperature T_a on the results of the more simple tests used in certification testing of sheets of low alloy steel. These include widely used test to determine the NDT — «temperature of zero plasticity», and testing to determine the temperature dependency of the fracture type (T_kb temperature — the static bending temperature, DWTT temperature — in impact bending). By numerical FEM simulation of the process of crack propagation in the specimen NDT received that determined in these tests the temperature of NDT corresponds to the critical stress intensity factor K_1a during the crack arrest under plane strain conditions. This value is proportional to the material yield strength σ_Y at given temperature. Based on the results of previous work of the authors linking temperature T_a to the values of K_1a, σ_Y at given temperature and thickness of sheet metal t, correlation the ratio of the temperatures NDT and T_a, taking into account the material thickness and its yield stress is proposed. To link the fracture of full thickness specimen with the crack arrest conditions, the numerical simulation of crack propagation in the specimen with a blunt notch T_kb specimens was performed. It is shown fracture of specimens, loaded in full-scale yield, interpreted as the ratio of the quantities of the elements that «destroyed» by brittle mechanism, to the total number of elements in the plane of the fracture is in correlation with the condition of the crack arrest in a wide plate, loaded by the tension in the nominally elastic region. It is projected that in the determination of T_kb as the temperature corresponding to 70% of the viscous component in the fracture, it lies significantly below the temperature T_a.

Failure diagnosis of spiral bevel gears in assembly gearbox of aero engine is performed. With the use of physical methods of testing (scanning electron microscopy, electron-probe X-ray microanalysis) and microhardness testing the fracture origins and fracture kinetics are determined, the microstructure and microhardness of case are analyzed. It is found that the surface hardness in gear teeth root areas for fractured gears essentially less than for fault-free gears with big operating time. Service conditions of the gears on various engine setting are observed. 3D finite element modeling of the gears stress state is carried out. On the basis of the modeling it is shown that in operating range of the gears rotational speed there is the gears resonance under mode of bending vibration with three nodal diameters. With this, the location of maximum stress amplitude coincides with the site of the fatigue fracture origins. Finite element data are proved at the gears stress measurement in the course of engine tests. Thus, as a result of the complex study it is found that the cause of the bevel gears failure is intense gear resonance in the conditions of reduced surface hardness for gear teeth root areas. The measures intended to elimination of the failure causes are developed, approved and introduced.

This paper describes a promising technique of nondestructive expert quantitative assessment of critical stress intensity factor values (K_1c) for 38KhN3MFA structural steel subjected to various modes of heat treatment. This method is based on ultrasonic scanning and mechanical tests of heat-strengthened samples of 38KhN3MFA steel after quenching from 850°C and tempering in a wide range of temperatures: 200, 400, 500, 580, 620°C. As a result, new correlations of considerable scientific interest were obtained between the velocity of longitudinal and transverse elastic waves and the mechanical properties of steel, including the values of critical stress intensity factor for structures. The proposed model, which explains the change in acoustic properties of 38KhN3MFA steel on the basis of the phase changes taking place in the structure during tempering, will allow similar studies to be carried out for other heat treatment modes and other steel grades. In this method, the coefficient K_1c is determined without breaking the integrity of structures. Deviation of the calculated critical stress intensity factors, derived using the acoustic measurement data, from the experimental values does not exceed 7.5%. The use of this method significantly reduces the amount of time and labor needed to determine mechanical characteristics of samples and finished products made of 38KhN3MFA steel since it will not be necessary to manufacture samples and carry out tests. The developed technique can be offered for introduction in manufacturing as the main or additional method of assessing mechanical parameters of materials subjected to various modes of heat treatment.