The article proposes a refined two-stage method for synthesizing a third-class lever mechanism for the implementation of the idle operation of a clutch-free mechanical press, which guarantees the assembly of this mechanism at full angle of rotation of the input crank.

The first stage determines the upper extreme position of the slider occupied during the press idle stroke, using a conditional four-bar linkage and an auxiliary coordinate system and also locations of the slider guide and the ordinate axes of the main coordinate system are found. The second stage of synthesis is conducted in accordance with design methods for mechanisms with an approximate dwell, based on the utilization of their extreme positions. The authors derive analytical relations to evaluate the magnitude of small displacements (oscillations) of the slider during the press idle stroke and the conditions of motion transmission.

Moreover, the authors demonstrate the example that confirms the possibility of implementing the idle mode of operation of a mechanical non-clutch press with a third-class lever mechanism of the same parameters assuming ts synthesis for the operating mode. The research demonstrates the possibility of obtaining minor fluctuations of the working slider in the idle mode of the press and also presents acceptable pressure angle modes.

Since the early 1990s, the ISO Technical Committee for Graphic Technology has developed and updated several dozen industry standards. Almost every one of them begins with a list of definitions for terms specific to the document.

To date, the series of standards accumulate a dozen variants of very ambiguous interpretations of the concept of tone value, which is the basic parameter for autotypic printing. It creates a problem of adequate translation of international standards and determines the relevance of the analysis of the currently existing contradictory interpretations, as well as the identification of the essential features of this term. In this regard, the concept and parameter "tone value" is considered in the historical context of improving models of illustration printing, considering the multi-stage nature of this process, as well as in solving the problems of color communication in the modern open and unclosed information environment.

The article experimentally and analytically shows the need for more metric-adjusted interpretations and definitions of the parameter versions for a stimulus, for example, brightness Y of the XYZ colorimetric metric of the International Commission on Lighting, or to the extent of impact — lightness L from the Lab of the International Commission on Lighting. The authors establish the fact of an inappropriate percentage expression inherent in the incentive for such a perceptual parameter as the Color Tone Value, which is important for the development of versions of domestic standards based on existing international regulations.

Keywords are currently used in scientific literature as one of the identifying features that helps determine the field of scientific research. Furthermore, keywords can be considered classification features for searching the required scientific information source.

Keywords are essential components of any scientific source, therefore, the formulation of keywords, as well as the choice of their number, are an important aspect in developing the structure of a scientific work. The "Keywords" section has been Obligatory in the standards being developed since 1992. The search for the necessary regulatory document in existing search engines can be carried out by keywords. The aim of the research is to analyse the degree to which the formulations of keywords correspond to the content of the standards.

The authors consider standards of three different classification groups from three sections of the All-Russian Classifier of Standards OK 001–2021. Moreover, the authors propose a system of indicators to quantify the effectiveness of using keywords in the title and text of the standard; conduct statistical processing of data on the keywords usage in the title and text of the standard; calculate coefficients that allow numerically assessing the situation based on the parameter whether all officially keywords are used at least once in the title or text of the standard. The research also calculates a coefficient showing the frequency of the officially assigned keywords usage in the text of the standard.

The results indicate that officially assigned keywords poorly identify the standard, as a result of which the search for the necessary regulatory document is ineffective.

The paper presents a computational approach for evaluating wind loads acting on working platforms of antenna-mast structures within the context of modern digitalized engineering workflows. The proposed method treats platform guardrails as spatial lattice systems and accounts for the individual aerodynamic behavior of each structural element.

The relevance of the research is proved by the high sensitivity of antenna-mast structures to wind and by the absence of standardized procedures for calculating loads on auxiliary components, which often forces engineers to rely on simplified estimations with limited accuracy. The aim is to improve the reliability of wind load assessment for working platforms and to develop an algorithm suitable for integration into digital lifecycle support systems. The method involves elementwise calculation of projected areas, aerodynamic drag coefficients, filling ratio, and porosity-related correction factors.

The algorithm is implemented in Microsoft Excel to ensure transparency, reproducibility, and seamless adoption in engineering practice. An approbation was performed on a real tower with a height of 70 m and a comparison was made with a simplified method of equivalent area. As a result, the simplified approach leads to an overestimation of the load by 5–28% and an underestimation up to –63%.

Therefore, the results highlight the scientific and practical significance of the development and its prospects for implementation in complex domestic automation systems for engineering calculations of antenna-mast structures.

This article presents the results of a study of debris particles, including their elemental composition, and an analysis of the potential impact of debris particles on welding bridge formation, which can lead to short circuits and wire breakage during of welding bridge formation at electrical discharge machining of the 5NiCrMo stamp steel on a Sodick VZ 300L machine.

The authors use the scanning electron microscopy, energy-dispersive X-ray spectroscopy and the laser diffraction analysis to determine the size, morphology, shape and elemental composition of debris particles. Moreover, the authors have established that the average debris particles sizes are 25.04 ± 5.26 microns for samples from the tabletop and 20.97 ± 15.10 microns for samples from the bottom of the tub. The proportion of effective particles with a critical size (greater than 25 microns) that contribute to welding bridge formation reaches 35 % (for particles from the tabletop) and 45 % (for particles from the bottom of the tub). An elemental analysis reveals that the particle consists of zinc and copper, corresponding to the elemental composition of the electrode-tool — brass material.

Therefore, the results provide a better understanding of the defect formation mechanism and suggest measures to optimise the process.

The article discusses the use of a plasma-liquid system with solid and liquid electrodes for welding plates of brass. The purpose of the research is to study the possibility of welding brass plates using the method of plasma-liquid welding with solid and liquid electrodes.

The authors demonstrate an experimental installation for producing a welded joint, which can later be used to create industrial plasma welding installations. The research methods are presented, such as scanning electron microscopy, which allow analysing the structure of the weld, as well as checking the hardness of the alloy according to Vickers’ microhardness tester. Moreover, the authors present a detailed analysis of the voltage features, on the basis of which it is revealed that an arc discharge is involved in the welding process.

The experimental results demonstrate the potential of the method and show the most optimal welding parameters (voltage not less than 500 V, current up to 120 A). The resulting weld has small gas pores, but the structure remains similar to that of the base metal. In conclusion, the authors propose the development options of the method, such as the use of a mixture of various salts and acids in the electrolyte and the use of a vacuum chamber to minimize metal oxidation.

The article discusses the physical foundations of laser metalworking processes, including the features of the interaction of laser radiation with the material, the mechanisms of energy absorption and the patterns of thermal effects in the processing area. The aim of the research is to determine the rational modes of laser treatment of the 12X18H10T steel, minimizing the zone of thermal influence and improving the quality of the treated surface.

The authors conduct the analysis of the processes of melting, evaporation and formation of the thermal influence zone during laser cutting of metal materials. Moreover, the authors present an overview of the main types of industrial lasers used in modern laser processing technologies, including gas, solid-state and fiber laser sources, as well as their technological features, advantages and applications. Special attention is made on the effect of processing modes on the surface quality and the size of the modified layer. The article considers the properties and functions of process gases used in laser cutting and metal plating, as well as their effect on melt removal efficiency and reduction of thermal defects.

The experimental part demonstrates the laser cutting of the 12X18H10T steel with a thickness of 0.8 mm on a DMG MORI Lasertec 20 installation with varying laser radiation power. The article analyses the structure of the modified layer and the nature of the thermal effect on the material and also establishes optimal processing parameters to ensure the minimum thickness of the heat-affected zone and stable cut formation. The results confirm the high efficiency of the laser technologies usage in the processing of stainless steels and the possibility to use them for high-precision manufacturing of thin-sheet structures for aviation and machine-building purposes.

The uncertainty of the initial data and the limited number of use cases significantly complicate the prediction of the features of new components of aviation technology in the early stages of development. The aim of the research is to form a method of precedent forecasting, which allow evaluating the features of the projected part of a product in conditions of a lack of a priori information and with a nonlinear relations between design conditions and target parameters.

The method is based on the representation of the design situation in the form of a vector of conditions (X) and a vector of predicted properties (Y), as well as on the use of an observation protocol based on previously developed analogues. In case of a small number of precedents, the author proposes a multidimensional linear extrapolation procedure based on constructing subspaces of conditions and solutions and projecting a new design situation onto the space of known analogues. Moreover, in case of a significant sample and a nonlinear connection between input and output parameters, the author provides a neural network model based on a self-organizing Kohonen map.

The article formalizes the conditions for the application of both procedures, defines their mathematical models, and determines the principles for choosing the structure of the prognostic network. The practical significance of the results lies in the possibility of using accumulated design precedents for a preliminary assessment of product properties, reducing the number of design iterations and increasing the validity of design decisions.

The development of methods and algorithms for calculating the protection of various elements and objects of electric power systems from direct lightning strikes or the consequences of lightning striking nearby structures will always remain an important scientific and technical problem. Moreover, it is important not only to improve the regulatory and methodological framework, but also to develop promising innovative solutions. These approaches are also applicable to lightning protection of energy facilities, which is an important component of the electromagnetic environment of electrical substations.

The aim of the research is to develop an algorithm for calculating lightning protection for energy facilities, based on a synthesis of existing calculation methods taking into account the current electromagnetic environment. A review of regulatory documents and similar studies in this sector of the electric power industry is provided. An analysis of the reviewed sources shows that when designing lightning protection devices for various objects, there are sections and areas requiring clarification of the methods for calculating lightning protection parameters presented in current regulatory documents. Based on existing lightning protection design methods, an algorithm for calculating the parameters of substation lightning protection elements is proposed.

The presented algorithm can be used to develop appropriate programs that allow calculating and constructing a 3D model of lightning protection for power industry facilities.

Providing the quality of electricity and electromagnetic compatibility is currently a high priority for energy security. The energy infrastructure is considered as one of the critically important infrastructures of the Russian Federation. The introduction of modern electrical equipment and their control systems in enterprises of various industries leads to a decrease in the electricity quality. The development of industry in the Russian Federation and the continuous growth of the capacity of electric consumers lead to a violation of regulatory and technical documentation regarding the quality of electricity. Thus, it reduces the noise immunity and leads to the conductive low-frequency electromagnetic interference. These facts determine the importance of the problem of electricity quality and electromagnetic compatibility.

The aim of the research is to study the ways of the emergence and distribution of the conductive lowfrequency electromagnetic interference and ways of their attenuation.

The authors present a sequence of actions for the analysis and determination of the conductive low-frequency electromagnetic interference. Moreover, the authors consider issues of studying the nature of emerging the conductive low-frequency electromagnetic interference, its spread in electric power systems and ways to deal with them.

The implementation of modern trends and methods to eliminate electromagnetic interference allows not only assessing in advance the impact of interference on the elements of electric power systems, but also on the reliability, efficiency and stability of power supply.

The basis for the development of the aviation industry is the continuous process of changing the designs, Type of operation and operating conditions of the applied electromechanical energy converters. An additional factor is the expansion of the trend for hybrid power plants abroad, which allows increasing the level of electrification of the aircraft and providing another step towards creating a “more electric aircraft”. One of these steps is the integration of electromechanical energy converters in the form of a starter generator into an aircraft engine, which allows providing greater compactness, unification of technologies and increasing the strength of the elements of the integrated converter.

This paper examines approaches to the development and manufacture of rotors and starter-generators for aircraft engines. The authors analyse the design of the rotor, integrated starter-generator and the materials; present calculated load data for the rotor shroud and magnets during operation and review the results of acceleration tests of rotors with permanent magnets.

The aim of the research is to evaluate the feasibility of using a composite bandage for an integrated starter-generator, as well as to analyse the potential damage to the bandage and permanent magnets used in the rotor design. The research demonstrates calculated and experimental data indicating the feasibility of using the composite bandage for rotors with rotational speeds of up to 40.000 rpm. Moreover, the authors develop an algorithm for estimating the safety margin and conduct an experimental testing. The results highlight potential defects in the bandage and magnets, identifying the underlying causes and preventing their recurrence.

The urgent task in the construction of foundations and bases is to improve the technologies for preparing the soils, which should meet the requirements of regulatory documentation. It not only ensures the operational reliability of the soil bases, but also reduces the material costs at the preparation stage.

An important condition for ensuring the reliability of the bases is the rational moistening at the preparation stage. Conducting laboratory research to investigate the moisture indicators of the soil bases helps to improve the technologies and achieve the best results.

Therefore, the aim of the research is to develop the device design for monitoring soil moisture in space using empirical research methods. The term in space means the ability to obtain information about moisture not only at a single point, but potentially with a certain spatial resolution, which can be useful for analysing the heterogeneity of moisture distribution in a specific area.

The paper presents the results of developing the device design for monitoring soil moisture in space, which allows determining the moisture content of each layer of the sandy soil with a given amount of water by laboratory studies. The obtained data allows developing a mathematical model of layer-by-layer soil moisture.

The article demonstrates the results of the development and research of an approach that allows constructing a computational grid of a thin stepped gas layer that provides load-bearing capacity in the supports of high-precision measuring and diagnostic equipment. Moreover, it is noted that traditional methods for automatic generation of the computational grid usually lead to distortion of the initial geometry and, as a result, to the impossibility of correct modeling of the gas flow.

The author suggests a method based on decomposing the model into simple bodies, which allows forming a computational grid of the correct structure with the required shape and orientation of the elements. An important component of the proposed methodology is a set of settings applied to the model in order to provide interband interfaces, adjust boundary conditions, as well as for subsequent initialization of the solution and ensure convergence in calculations in the ANSYS Fluent system.

In addition, the author presents the results that demonstrate the course of test calculations and validate the effectiveness of the proposed approach during the simulation of the lubricating gas layer.

The article aims at considering the possibilities and finding new ways to constructively improve contact measuring heads for high-precision 3D control of geometric parameters of complex products on coordinate measuring machines. Technical solutions based on optical methods and measuring instruments, in particular, fiber-optic sensors are also considered.

The article discusses two types of contact measuring heads with rigid and movable measuring rods. The features of two variants of measuring heads of the first type are considered, implemented on the basis of measurements of micro bends of the measuring rod by means of sensors with fiber Bragg gratings or fiber interferometric sensors built into it. Options for the second type of measuring heads with a movable measuring rod and measuring its displacements when touching a controlled part based on the use of a fiber-optic scanner or a three-axis fiber interferometric sensor are also discussed.

It is shown that in the latter case, the sensitivity threshold along three axes can potentially have subpicometric values. The option of embedding a miniature wide-angle Fisheye video camera to visualize the approximation of the measuring tip to the controlled part by recording and measuring the geometric parameters of the formed Newton rings is discussed.

The article presents the development of the design of sensitive elements of reusable sensors for simultaneous registration of parameters of vital systems of the human body and experimental verification of the technical features of prototype samples.

The author uses methods of designing and manufacturing multilayer printed circuit boards, 3D modeling of the sensors design and their interface with existing solutions. Computational methods are also applied to the dependence model of sensor features on changes in temperature and concentration of the measured substances. Moreover, an experimental approbation of an experimental batch of sensors is carried out.

The research suggests technical solutions for the design of sensors for simultaneous registration of several parameters of the human body in long-term monitoring of vital systems of the human body such as reusable combined electrodes "ECG temperature" and "ECG metabolism". Technological capabilities of the production of standard printed circuit boards are used for the manufacture of sensors, due to which the high manufacturability and low cost of sensors are achieved.

Sensors can be used both for short-term monitoring of a patients’ condition during functional and pharmacological tests and for long-term recording of parameters as part of wearable multi-channel human body monitoring systems.

The relevance of the research is determined by the need to improve the efficiency of managing complex agricultural equipment in agricultural enterprises of the Russian Federation. In the context of an increasing number of emergencies, a key role is assigned to the dispatcher of the situation center, whose efficiency of actions directly depends on the quality of the graphical interface of the visualization system Therefore, the aim of the research is to reduce the time for eliminating emergency situations by optimizing the time of the information analysis and decision-making by the dispatcher based on a cognitive-graphical interface.

The article proposes an original formalisation of the total time to eliminate an accident, presented as the sum of four independent components: the time to detect and identify an accident, the time to analyse information and make a decision, the time for logistics and the time to eliminate an accident. It is shown that the most manageable factor is the second component, which depends on the method of decision support and the quality of the graphical interface. To optimize it, the authors provide a cognitive graphical interface based on the Novoselov fractal, which implements a hierarchical self-similar visualisation structure. Moreover, 36 controlled parameters are integrated in a single interactive window, grouped into six semantic blocks (complexity of the situation, danger, weather conditions, team composition, available funds, logistics).

The experimental results show that the proposed interface reduces the time for information analysis and decision-making by 30–40 % compared to classical interfaces without loss of accuracy. The developed principles can be used to modernize the software of situational centers of agro-industrial enterprises.