The properties of nanostructured materials based on zinc and indium oxides can be modified by adding alloying elements to obtain the necessary electrical or optical properties. For example, the specificity of the chemical properties of ZnO and In₂O₃ for the determination of toxic gases is achieved by immobilizing Au, Ag, etc. nanoparticles on their surface. Control of the material composition plays an important role in determining the dependence between the dopant content and functional properties of the materials. The study is aimed at the development of a methodical approach to the multi-element determination of catalytic dopants (Ag, Au) and matrix elements in nanostructured tin and indium oxides atomic using continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS). The matrix of the synthesized nanostructured materials (NM) is formed by the corresponding oxide with possible oxygen deficiency occurred due to the temperature conditions of synthesis (300 – 700°C), and the content of additives (Ag, Au) being varied from 1 to 3 % wt. Pyrolysis and atomization conditions for sequential multi-element atomic absorption analysis are determined. The most suitable pyrolysis temperatures upon HR CS GFAAS determinations of Ag and Au (for both In and Zn oxides), are 1000, 1600, 1200 and 900°C, respectively. The most suitable atomization temperatures for ETAA-NIS determinations of Ag, Au (for indium oxide based NM, Au (for zinc oxide based NM), In, and Zn are 1800, 2200, 2100, 2200, and 1500°C, respectively. The accuracy of analyte determination reached 1 – 4 % rel. The correctness of the results was proved by inductively coupled plasma mass spectrometry. The developed method provides control of the composition of synthesized nanostructured materials for their more efficient use in photovoltaics, as well as in production of chemical sensors for detection of harmful compounds like CO, NO₂, NH₃.

A comparison of different standard samples — artificial glass SRM-612 (Standard Reference Material) and standard samples of natural composition SG-1A, SG-3, ST-1A and SGD-1A — used for external calibration in the elemental analysis of silicate rocks in the form of fused glasses by inductively coupled plasma mass spectrometry and laser ablation (LA-ICP-MS) is carried out with a goal of selecting the most suitable samples for plotting calibration dependence upon determination of the major and trace elements when using LA-ICP-MS for routine analysis. The results showed that the error of determination for both major and trace elements is lower (compared to SRM-612) when external calibration is carried out using the reference materials of natural composition with Si and Fe contents close to those in the analyzed samples. The use of internal standards in both cases decreases the systematic error attributed to the drift of LA parameters and different ablation yields. The correctness of the determination of 28 elements is proved in comparison of the results of the analysis of four standard samples with the reference values. The obtained results are used to select calibration standards for LA-ICP-MS analysis of the samples of unknown composition. The results of analysis of six samples of unknown composition match to the error limit the results of X-ray fluorescence analysis (major elements) and ICP-MS (trace elements in solutions). Refining of the content of trace elements in the previously certified reference materials allows them to be used for calibration in routine analysis of geological rocks. The developed LA-ISP-MS technique is a rapid method for determination of a wide range of elements, in particular rare earth elements, in silicate rocks and can be used for routine analysis without additional sample preparation after X-ray fluorescence analysis.

4-(2, 4-bis((2-aminoethyl)-imino)pentane-3-yl)diazenyl)benzoic acid was synthesized using 3-[4-carboxyphenylazo]pentanedione-2,4 (R) reagent obtained by the standard procedure. The composition and structure of the synthesized reagent is determined by the methods of elemental analysis and NMR spectroscopy. The complexation of copper (II) with 3-[4-carboxyphenylazo]pentanedione-2,4 (R) in the presence and in the absence of 8-hydroxyquinoline, diphenylguanidine and ethylenediamine was studied spectrophotometrically. Optimal conditions for complexation are specified and composition of homo- and mixed-ligand complexes are determined. When copper (II) interacts with R at pH 3 – 10, the maximum yield of the complex compound is observed at pH 5 λ_max = 553 nm. The molar absorption coefficients and the stability constants of copper (II) complexes were determined. A range in which Beer’s law is valid is determined. Study of the complex with 8-hydroxyquinoline (Ox), diphenylguanidine (DPG) and ethylenediamine (ED) present showed that under the effect of these compounds, the optical density of the complex solutions significantly increases and the pH value of the medium providing optimal complexing shifts to the acidic region: pH 2 – 3. The maxima of the absorption of mixed-ligand complexes are observed at λ = 564 nm (CuR₂-Ox), λ = 568 nm (CuR₂-DFG), λ = 576 nm (CuR₂-Ed). Comparison of the values of the stability constants of homo- and mixed-ligand Cu (II) complexes shows that CuR₂-ED is more stable than the other ones under study. The effect of foreign ions and masking substances on complexation was studied. The selectivity of the obtained reagent for copper (II) determination, compared to the reagents of the same duty known from the literature appeared advantageous. The high selectivity of the studied reactions provided developing of a rapid method for copper determination in rocks. A procedure for the spectrophotometric determination of copper (II) in pyrite is developed.

The results of repeated serial comparative laboratory studies of the corrosive effects of different coolants (OZh-40 and KhNT-NV-40) based on ethylene- and propylene glycol, respectively, are presented. A significant discrepancy is revealed between the obtained results according to accepted and approved procedures for the test-plates continuously exposed for 336 h at a temperature of 88 ± 2°C in the same batch of test antifreeze. The current standards do not regulate the frequency of their using, i.e., the number of exposures of the control samples of the main groups of ferrous and non-ferrous metals, but only limit their thickness, which is naturally reduced due to corrosion and routine cleanings. The use of highly effective corrosion inhibitors in antifreezes allows the plates to be kept within the permissible thickness for about 10 tests, however, the relative error of assessing the corrosion effect between parallel series significantly increases. Strengthening of the requirements to the operational safety and depreciation period of heat exchange equipment, systems and production complexes, development and conversion of the new heating agent and coolants entails the necessity of elimination of the system errors in the tests, the results of which are used by design engineers, developers, manufacturers and consumers. Corrosion tests of the coolants showed that the number of exposures of the test plates affected the accuracy of the obtained data. Recommendations regarding limitation of the number of plate exposures and, accordingly, elimination of the system errors and ensuring an acceptable error in determination of the corrosion rate (corrosion effect) are specified with the goal to increase the accuracy of the corrosion measurements upon production and operation monitoring, as well as the efficiency of the selection of antifreeze and additives to them.

A review of the structural elements (individual components, printed circuit boards, etc.) of X-ray systems intended for inspection of electronic products is presented. The basic principles of constructing such systems and typical composition of the equipment capable of providing the minimum necessary functionality are considered. Among the main technical characteristics an emphasis is made on the resolution power, which depends on the pixel size and thickness of the scintillator layer of the X-ray detector, as well as on the size of the effective focal spot of the X-ray tube. Comparative analysis of the advantages and shortcomings of clastic (open type) and sealed (closed type) X-ray tubes – one of the main nodes of such systems-is carried out. A structural diagram of a clastic X-ray tube is presented along with and the characteristics of domestic and foreign developments. The main disadvantages of the systems based on clastic tubes are considered. Large dimensions, large weight, relative complexity of the construction, presence of the vacuum-tight collapsible connections, the necessity of using a pumping system providing high vacuum, the necessity of high-voltage training of the tube assemblies after their replacement, and high cost are noted separately. The design of sealed off BS microfocus X-ray tube and radiation sources on their base which can be used in the development of domestic X-ray systems are briefly described. The diameter and length of the metal-glass cylinder tube are 75 and 315 mm, and the diameter and length of the copper anode tube 10 and 100 mm, respectively. A tungsten target is deposited on a beryllium substrate (X-ray tube exit window) with a thickness of 0.2 mm. The minimum focal length during x-ray photography is 0.5 mm. A comparative analysis of the characteristics of a clastic (collapsible) X-ray tube with continuous pumping and an X-ray tube sealed from an exhaust cart revealed the possibility of successful use of sealed tubes in modern X-ray systems used for inspection applications.

A comprehensive study of the lithological and petrophysical properties of rocks includes the following methods of research: petrographic, petrophysical, and methods of nuclear physics. The choice of petrophysical methods depends on their ability to determine desired minerals and non-mineral components. The research scheme is developed taking into account the description of core sections, a qualitative determination of the composition of the rock, as well as an approximate calculation of the areas occupied by the minerals in the thin rock section. In the analysis of complex reservoirs, in addition to standard estimates of porosity, permeability, water-holding capacity, etc., additional special studies are needed, e.g., to determine the quantitative content of minerals, it is necessary to use the methods of x-ray structural analysis, however here we faces a known problem of identification of the minerals by the captured diffractograms. It is known that the rocks of Western Siberia include mainly quartz, potassium-sodium and calcium-sodium feldspars. Feldspars are the most important family of rock-forming minerals, they make up to 60% of the volume of the earth’s crust (up to 50% of its mass). Most of the feldspars are included in the ternary system NaAlSi₃O₈ – KAlSi₃O₈ – CaAl₂Si₂O₈. All crystal structures of the feldspars are based on a similar Si – Al tetrahedral skeleton frame [AlSi₃O₈], and thus are almost indistinguishable in the diffraction patterns. A method of quantitative x-ray and phase analysis is developed for selective determination of the concentrations of calcium and potassium feldspars. A method for separating the peaks of the characteristic radiation of mineral elements is proposed. The conditions and optimal parameters of x-ray phase and x-ray fluorescence analysis are specified to determine the total mineral content and calcium concentration (using an X-ray tube with a titanium anode and a scandium filter).

It is showed that for all facilities of the machine-building engineering complex the solution of the problems of strength, life time and crack resistance is confined to scientifically grounded determination of the admissible design parameters of the life time and keeping the levels of stresses and deformations of the bearing elements of the objects in question within the permissible limits. This requirement is extended to the basic operational design parameters — durability in cycling and time, size of the flaws, temperature, and deformation rate. Then the equations of state corresponding to the indicated cases, supported by the necessary computational and experimental information, provide a possibility to assess the conditions for attaining the limiting states of the objects under consideration by the values of corresponding margins. The developed approach is used in analysis of traditional methods of design, manufacture and the operation of the equipment which are based on determinate criteria of static, long-term, cyclic, dynamic, and temperature strength, as well as on the standard characteristics of the mechanical properties of structural materials, analysis of the rated and limiting stress states of bearing structures with allowance for the margin values of stresses, strains and life time. An emphasis is made on the necessity of going to the generalized analysis of the fracture criteria on the basis of multifactor computational and experimental methods of margin determination when calculating strength, life time and crack resistance. According to the considered approach it is stated that the general formulation and solution of fundamental problems of analysis and provision of nominal and abnormal operation of technogenic objects is based on their straight quantitative connection with the problems of constructing equations of state, solving the boundary value problems and formulating the criteria of limiting states along with assessment of the margins of strength, life time and crack resistance. A complex and mutually consistent system of deformation and fracture curves is constructed proceeding from the characteristics of the mechanical properties of materials inherent to the estimates of the stress-strain and limiting states. Linear (elastic) and nonlinear (elasto-plastic) approaches to construction of kinetic equations characterizing in general the processes of nucleation and development of damage and fracture zones which are responsible for margin reduction are considered and analyzed as most important ones.

One of the important features of the fracture of heterogeneous materials with a stress concentrator is the scale effect associated with the dependence of the nominal stress on the specimen size. This effect must be considered when studying the fracture process of concrete to improve the operation safety of concrete structures. The purpose of this work is to study the size effect of the specimens with a notch made of a concrete (class B25, R = 28 MPa) on the strength characteristics and parameters of the acoustic emission(AE) recorded in the process of fracture. Three-point bend tests with registration of AE signals were carried out using specimens of three sizes (1075, 465, and 215 mm long), their geometry corresponded to two-dimensional similarity, since the thickness of the specimens remained unchanged, and both length to width ratio for the specimen and notch remained constant. The size of the zone of fracture localization at different stages of crack development were estimated on the larger specimens using planar AE location and the time dependence of the zone size was plotted. The size of the localization zone of small specimens was determined by measuring the ultrasound attenuation coefficient. Analysis of the loading diagrams combined with the time dependences of the AE parameters revealed that the specimen size affects the fracture staging. The dependences of the rated strength, fracture energy, b_AE-parameter, and the total number of AE signals on the specimen size are plotted. It is shown that the size effect is associated with a decrease in the rated stress for the large-sized specimens and number of accumulated acoustic emission signals, as well as with an increase in the fracture energy and b_AE-parameter. It is assumed that change in the AE characteristics with increasing size of the specimen is attributed to a decrease in the relative fraction of structural heterogeneity (the ratio of the average size of granite aggregate to the specimen size) in large specimens. New data were obtained regarding the effect of the size of concrete specimens on the acoustic characteristics.

Bacterial cellulose (BC) finds multiple applications due to unique physicochemical properties and biocompatibility. The mechanical characteristics of hydrated BC such as Young modulus, tear strength, and tensile elongation under maximum load are crucial in some instances. The diversity of test methods does not allow correct comparison of the results of BC thermomechanical analysis (TMA) obtained by different researchers. However, current standards for determination of the mechanical characteristics are not intended for highly hydrated samples and do not take into account conditions for their use. The goal of the study is to develop a tensile test method for hydrated gel films of bacterial cellulose and to compare their relative elongation when tested in air and in an aqueous medium. Test samples were produced in a synthetic nutrient broth using Medusomyces gisevii Sa-12 symbiont. Physico-mechanical analysis was performed on a TMA-60 thermomechanical analyzer. The loading rate was selected proceeding from the requirement that the specimen will not dry out when tested in air. The microfibrillar structure of BC samples was studied before and after stretching using scanning electron microscope (JSM-840). The results showed that at different loading rate, tensile strength varies by a factor of 16, Young’s modulus, and elongation at maximum load by a factor of 1.3 and 1.5, respectively. The maximum tensile elongation of hydrated BC in an aqueous medium (51.4%) is 3.1 times larger compared to that determined for the test specimen tested in air. The recommended loading rate is 20 g/min. The BC structure changes during tension: after testing the BC fibers line up along the load vector and thus structured bacterial cellulose acquires the anisotropic properties.

The capabilities of the STARLIMS laboratory information management system to ensure the compliance with the criteria for accreditation of testing laboratories using a systematic approach to the formation, updating, storage and prompt provision of obvious and convincing evidence are analyzed. It is shown how the information system provides management of the document flow, personnel, equipment and measuring instruments, facilities and standard samples in laboratories. The functions of the specialized Lab5725 module for implementation of the mechanisms of intralaboratory control (ILC) and the automation of processes for confirming the compliance of the measurement results with the requirements of GOST R ISO 5725–2002 [1] are described. The module is able to plan and process the ILC results according to the specified rules and with required frequency. To implement the mandatory plans for round robin tests, a special project containing information about the samples provided by the round robin test provider for further testing can be also developed by STARLIMS. Information about the test results is accumulated in the report forms accepted by the provider, and sent to him for further processing, analysis and summing up. Following the logic of the risk-based approach incorporated in the ISO/IEC 17025:2017 standard [2], we highlight the main risks that may arise from the development and implementation of the laboratory information system and discuss the possibility of their elimination. A specialized «Accreditation» interface has been developed on the STARLIMS base, which allows prompt requesting and structuring of the information in the form of the documents to confirm compliance with the accreditation criteria. The demonstrated capabilities of the STARLIMS laboratory system lead to a significant simplification in the preparation of laboratories for accreditation and competence verification and increase the reliability of the information provided to assessors.

Developing of additive manufacturing and the use of additive technologies at all stages of the product life cycle entails the necessity of developing methods providing control of their characteristics. Here we consider application of the optical measurement procedures to the objects of complicated shape. Products manufactured by the methods of additive technologies may have defects such as delamination, starved joint, porosity, warp, stress-strain state, roughness, etc. We present the devices designed and developed on the principles of interference, structured light and holography at the «VNIIOFI» Federal State Unitary Enterprise to identify the defects in the products of additive technologies. The advantages and shortcomings of the interference microscope, scanner-profilometer, and shearograph are examined with regard to the control of the aforementioned types of geometric defects. The special feature of the contact-free methods is the possibility of control of different types of materials: metals and dielectrics, transparent, reflective, scattering and composite materials. The results of experimental study aimed at detection of the surface and subsurface defects are presented. Interferograms and results of phase reconstruction are presented both for reflective and transparent objects. Defects of the refractive index of the microcavity made of an optical fiber were detected. Metrological characteristics of optical devices for non-destructive testing of products are estimated. Standards for calibration and graduation of the optical devices considered in the study were manufactured and tested. The use of specially developed standards makes it possible to use these methods both for qualitative assessment of the objects of complicated shape and flaw detection and for quantitative estimation of their characteristics.