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The quality of printing products substantially depends on the accuracy of the individual mechanisms of the printing equipment. Since technological processes usually last in a period of a second, conventional measuring instruments turn out to be too inertial; therefore, to detect deviations of the given parameters (loads, locations, accelerations) from the calculated values, various sensors are used. The work is devoted to the selection of diagnostic tools for typical measurements used in print media equipment on printing equipment. Possibilities of parallel measurements and mutual analysis of signals of the designed diagnostic systems for research of parameters of the equipment of the print media industry are considered.

To study the effect of the radial density profile of the material of a metal-plasma Z-pinch load on the development of magneto-Rayleigh–Taylor (MRT) instabilities, experiments have been performed at the Institute of High Current Electronics with the GIT-12 generator which produces microsecond rise time megaampere currents. The Z-pinch load was an aluminum plasma jet (PJ) with an outer plasma shell. This configuration leads to the formation of a uniform current sheath in a Z-pinch load upon application of a high-voltage pulse. It was successfully used in experiments with hybrid deuterium gas-puffs (Klir et al 2020 New J. Phys. 22 103036). The initial density profiles of the Z-pinch loads were estimated from the pinch current and voltage waveforms using the zero-dimensional ‘snowplow’ model, and they were verified by simulating the expansion of the PJ formed by a vacuum arc using a two-dimensional quasi-neutral hybrid model (Shmelev et al 2020 Phys. Plasmas 27 092708). Two Z-pinch load configurations were used in the experiments. The first configuration provided tailored load density profiles, which could be described as ρ(r) ≈ 1/r^s for s > 2. In this case, MRT instabilities were suppressed and thus a K-shell radiation yield of 11 kJ cm−1 and a peak power of 0.67 TW cm−1 could be attained at a current of about 3 MA. For the second configuration, the radial density profiles were intentionally changed using a reflector. This led to the appearance of a notch in the density profiles at radii of 1–3 cm from the pinch axis and to magnetohydrodynamic instabilities at the final implosion stage. As a result, the K-shell radiation yield more than halved and the power decreased to 0.15 TW cm−1 at a current of about 3.5 MA.

The goal of this work is to research a possibility of laser projection system adaptation to a machine-building manufacturing enterprise. A model example of the use of a computer vision system in production is the task of reducing the labor intensity of installing welded elements on a product, reducing the production time, and reducing the cost of work. A formal statement of the problem is given - to use a laser projection system in the conditions of assembly and welding production for positioning welded elements on the main product with respect to dimensional accuracy. For experimental research, a section of a machine-building production enterprise with a pre-defective product and welded elements was used. The research took place in two stages. As a result of the research, the results were obtained, confirming the efficiency of the method.

During the operation of machines and aggregates, processes, that are difficult to describe in theoretical ways, occur. When studying the mechanism in detail, it is still better to resort to experimental measurements in order to gain a greater understanding of the transients that occur during its operation, movement, and shut down. Such detailed data can be used to improve the properties of the mechanism, the principles of its design, as well as to reduce its dimensions and energy consumption. An acceleration sensor was developed, which will allow to investigate the causes of problems with mechanism precision, occurrence of noise, as well as identify a poor assembly and adjust machine mechanisms.

As part of the implementation of a set of works on the examination of the technical condition, calculation justification and assessment of the remaining service life of the group of buildings of the Left-Bank State Border Service of the city of Voronezh, the development of “Methodology for assessing the technical condition and calculation forecasting and justification of the remaining service life of building structures” was carried out. When developing the methodology, the requirements of the current regulatory and technical documents for the inspection of buildings and structures were taken into account. The methodology of the calculation justification is based on previously published works of the creative team under the direction of Shmelev G. D. The methodology for calculating forecasting and estimating the remaining service life of building structures is based on the following methods: expert, parametric, “load - bearing capacity” and “load - deformation”. This article provides a brief description of the methodology and its main sections. The general content of the methodology, which consists of 11 sections, is given, a detailed description of the 3 key sections of the methodology is given, which are devoted to: determining design parameters and criteria for their evaluation; methods for predicting the residual life of building structures; drawing up a report on the justification of the remaining service life of the building structures of the facility.

Individual walls of structures based on wedge-type scaffolding can be different in height and are often used as enclosing structures for different cultural and sporting events. Usually, such structures are covered in the longitudinal direction with an awning cloth on both sides, which is why they take on the full wind load from the entire area of the awning. When calculating such structures, the wind load is the determining load. In practice, these structures are built according to the recommendations of the manufacturer’s catalog of scaffolding, and they are repeatedly statically indeterminate systems with a large number of unloaded elements. This increases the material consumption of the structure and increases the cost of transport and installation work. In structures made of modular scaffolding, diagonal elements are used to give spatial rigidity to the structure, to reduce the calculated length of vertical elements, and to perceive the shift movements of the cell caused by uneven vertical movements of adjacent posts and horizontal loads. A structure with a full set of diagonal elements has a large number of weakly loaded elements. In this regard, it is possible to perform the so-called «discharged» construction scheme for more efficient use, replacing rigid diagonal elements with cable ties and reducing the number of diagonal elements in the longitudinal direction. The main task of the work is to analyze the stress-strain states of both the original system with rigid diagonal elements and systems obtained by partially replacing standard diagonals with flexible connections in the form of pre-stressed and non-pre-stressed cable ties. In order to study the actual operation of elements of rod collapsible structures and improve their design solutions, an experimental study of a fragment of the Layher system with cable ties was performed. Based on the experiment, it was determined that the actual movements when using flexible connections differ significantly from the calculated ones. The reason for the discrepancy is the deformation of the elements in the attachment points. To increase the rigidity, the design of the attachment unit needs to be changed.

Large-scale mass events (sports, entertainment, etc.) require safe and high-quality organization of the visual and stage sector, so there is a need for pre-fabricated and mobile rod structures. To solve such problems, it is convenient to use the Layher system of modular building structures. The criterion for design failure is the failure of one of the most loaded elements, even when the entire system as a whole still has some resource. Compensating devices can be a solution to this problem. This study solves the problem of redistribution of forces in the rods using compensating devices, taking into account the stress state of the rod system. In the event of failure of one or more elements, their internal forces are redistributed between adjacent elements in proportion to their stiffness, so spatial rod systems can fairly well resist progressive destruction. However, the destroyed element does not carry any further load and adjacent elements can also fail. Compensating devices leave overstressed rods in operation and thus increase the load-bearing capacity of the rod system. The invention relates to the field of construction and mechanical engineering, namely to rod metal structures and their elements that work on tension or compression, primarily in statically indeterminate systems. The purpose of the invention is to obtain stable axial forces in a limited range separately for compression and stretching with the possibility of adjusting their size and length of the element. This goal is achieved by the fact that in the process of manufacturing the force limiter, which includes coaxial rod elements with a collet clip, the contact surfaces are made with ring waves (teeth), which can have a sinusoidal, triangular and trapezoidal profile with different angles of inclination of the sides. The height and pitch of the ring waves are assigned from the conditions for performing the calculated range and speed of loads, and the angle of inclination of the profiles from the conditions for ensuring different rates of change in forces (compression/stretching). Arbitrary schemes have been studied, the use of compensating devices in which allows reducing the metal content of the structure by 20%. A compensating device was developed and calculated. An experiment was conducted to identify the redistribution of forces between elements when using compensating devices: the results generally coincide with theoretical calculations.

The results of a numerical simulation of the heating of a microprotrusion on the surface of a copper electrode under the influence of radiofrequency electromagnetic fields, performed for different temperatures of the electrode, are presented. The calculation model describes self-consistently the thermal processes in the electron and phonon subsystems, the electron emission, and the effect of the space charge of emitted electrons. It has been shown that when the initial electrode temperature is increased to 1000 K, the time of heating of the surface microprotrusion to a critical temperature decreases by a factor of 1.5–1.9, namely, to values ranging from a few to tens of nanoseconds. This may significantly increase the probability of radiofrequency vacuum breakdown on the surface of the accelerating structure of an electron-positron collider.

The paper analyzes advantages and drawbacks of the radioisotope thermoelectric generators (RTG) based on application of 238Pu and 232U. Currently, the RTG on 238Pu are widely used for long-term autonomous power supply of spaceships due to the following positive properties of 238Pu: high specific heat generation rate, long half-life, weak emission of neutrons and γ-rays. Isotope 238Pu may be produced by neutron irradiation of 237Np (main component of transuranium radioactive wastes) in nuclear reactors. The paper considers application of 232U for the same purpose because of the following positive properties of 232U: power elevation during initial 10 years of the RTG operation (effect of α and β-emitters in 232U decay chain), long half-life (comparable with 238Pu half-life). Unfortunately, 232U decay chain includes also intense emitters of high-energy γ-rays. As a compromise, a possibility is considered to create the RTG based on mixture of 238Pu with small (below 5%) additive of 232U. Such RTG will be able to keep long-term stable operation at high power level. The following two-step technology is proposed to produce 232U: generation of 231Pa in thorium blanket of hybrid thermonuclear reactors and subsequent neutron irradiation of 231Pa in nuclear reactors till accumulation of significant 232U quantities.

The paper substantiates the possibility of increasing the safety of fast reactors by surrounding the reactor core with a neutron reflector with special properties. The particular case of using lead isotope as a neutron reflector has been considered in the lead-cooled fast reactor in an exemplary manner. An asymptotic point kinetics model, which takes into account neutrons returning from the reflector to the reactor core and participating in the development of fission chain reaction, was proposed for assessment of the emerging effects. The in-hour equation for fast reactors, surrounded by a neutron reflector with special properties, has been developed. It was revealed that the neutron lifetime can be substantially increased. Therefore, the contribution of the neutron reflector would mitigate the consequences of accidents when inserted reactivity exceeds the effective fraction of delayed neutron. In addition, the maximum rates of power increase have been calculated for different cases of reactivity insertion. The obtained results have considerable practical value for scientific and advanced studies of reactor accidents.

The article is devoted to the urgent problem of large-scale production of plutonium-238. Various starting isotopes and Pu-238 production schemes are analyzed. The isotope characteristics of the chain based on the starting Np-237 isotope are presented. It has been substantiated that the region of neutron resonant absorption for the isotope Np-237 is the preferred spectrum of its irradiation. It is proposed to form a region with a preferred neutron spectrum in the fast reactor core for irradiation of neptunium-237. The preferred spectrum is achieved by a heterogeneous target structure including neptunium-237 and a moderator with a high atomic weight (Pb, Pb-208, Bi, Pb-Bi eutectic). It is shown that when a moderator with a high atomic weight is used, it becomes possible to form an extensive region with the preferred spectrum. In conclusion, the main conditions for the large-scale production of isotopically pure Pu-238 in a fast reactor are formulated.

The paper analyzes a possibility to involve hybrid thermonuclear reactors into the existing nuclear power systems. The possibility is related with production of non-traditional nuclear fuel in thorium blanket of hybrid thermonuclear reactors on D-T plasma. Non-traditional peculiarity of such a fuel consists in significant amounts of some non-traditional isotopes, namely231Pa and232U, together with traditional uranium isotope233U in the fuel. High-energy (14.1 MeV) thermonuclear neutrons can provide accumulation of significant231Pa and232U quantities through threshold (n,2n) and (n,3n) reactions. The promising features of the non-traditional fuel composition for nuclear power thermal reactors, basic component of the existing world-wide nuclear power industry, are defined by the following factors. As is known, 233U is able to provide more economical neutron balance in thermal reactors than235U and reactor-grade plutonium. The better neutron balance can result in higher values of the fuel breeding ratio and, as a consequence, in relaxation of the thermal reactors fuel self-sustainability problem. Isotopes231Pa and232U, being fertile and moderate fissionable nuclides, are able to stabilize time-dependent evolution of the thermal reactors power, prolong the thermal reactors lifetime through higher values of the fuel burn-up. Isotope232U, being intense α-emitter, is able to prevent any attempts for unauthorized usage of233U in nuclear explosive devices, i.e.232U can strengthen regime of nuclear non-proliferation. Thus, the hybrid thermonuclear reactors on D-T plasma with thorium blanket can be involved into nuclear power systems for generation of non-traditional, very promising fuel compositions for traditional nuclear power reactors.

The paper aims at studying specific peculiarities in isotope composition of thorium blanket under irradiation by fusion neutron source (FNS) in hybrid thermonuclear reactor (HTR). High-energy (14 MeV) component of neutron spectrum in thorium HTR blanket results in production of non-traditional fissile mixture including not only233U, but also231Pa232U and 234U. Extraction of such non-traditional fuel from spent Th-blanket and its utilization in traditional nuclear power reactors could increase fuel burn-up and strengthen regime of nuclear non-proliferation. The detailed investigations of these positive effects require high-precision neutron-physical analyses of thorium HTR blanket. The results obtained in these investigations are presented in the paper. The following results were obtained: the chosen model of HTR allowed us to form high-energy neutron spectrum in Th-blanket with significant fraction of 14 MeV neutrons; it was evaluated that threshold (n,2n) and (n,3n)-reactions are able to produce significant amounts of non-traditional target isotopes231Pa and232U; it was shown that accumulation of non-traditional target isotopes weakened substantially in depth of Th-blanket. So, it seems reasonable to seek for optimal thickness of Th-blanket and, thus, to find optimal loading of natural thorium.

We have fabricated the upconversion nanoparticles (NPs), which are nanocrystallites of 10 nm, doped with Yb3+ and Er3+ ions, prepared through hydrothermal method. Monitoring of their photophysical properties had been realized at different fabrication stages by using electron microscopy and luminescence spectroscopy under photoexcitation of the NPs with the 100 mW laser at 980 nm wavelength. The performed monitoring allows us to observe dramatic changes in the upconversion properties of the NPs during the sequence of the fabrication stages and revealed very strong correlation between the NPs’ upconversion efficiency and their structural specificities.

The article presents the results of studying the stress-strain state of the elements of the connection node of translucent modules with a load-bearing frame as part of a standard post-and-crossbar facade system. The research is aimed at studying the initial stresses and deformations of the system node elements in its design position without applying external loads. At the initial stage, experimental studies were conducted to determine the elastic modulus of rubber inserts, which are the main elements that transmit forces from translucent modules to the supporting frame of the system. Based on the results of the tests, an approximated graph of the dependence of stresses on deformations of rubber inserts was obtained, which was exported to the software package, for modeling their actual work when calculating by finite element methods. At the stage of numerical studies geometrically and physically nonlinear problems of contact interaction of elements were solved, the resulting picture of the stress-strain state of the node in position before the application of loads and impacts was created, the value of compression of the external pressure profile to the load-bearing frame was set.