n order to use the well-known Stechkin’s expression   in relation to different fuels, it is necessary to substitute into it the values of the lowest working calorific value of  and the stoichiometric ratio of   characteristic for each specific fuel. The corresponding values depend on the chemical composition of the fuel and are given in the reference literature. The calculation of the stoichiometric ratio is carried out according to oxidation formulas, assuming that the volume fraction of oxygen in the air is 21% and the mass fraction is 23%. However, in the cylinders of reciprocating internal combustion engines, the fuel is burned not in the air, but in its mixture with combustion products, which should lead to a deviation in the value of the oxygen fraction from the above-mentioned values and, consequently, to an increase in the stoichiometric ratio of  .

In this regard, the task is to take into account the effect of the content of neutral combustion products in the working mixture on the value of the stoichiometric ratio. To solve it, a thermodynamic analysis of the ratios of partial volumes of the components of the working mixture was used.

The article presents the dependencies obtained as a result of the analysis to determine the stoichiometric ratio depending on the fraction of neutral combustion products in the working mixture.

The paper describes a mechanism for modular cylinder deactivation in a connecting rod-less engine. An engine with such a mechanism can provide high fuel efficiency and reduce the amount of unburned hydrocarbons CH by improving the working process in the operating cylinders when cylinders are deactivated under low load conditions. The paper presents a design solution for the mechanism for modular cylinder deactivation by stopping the piston installed in a connecting rod-less engine containing two crankshafts in the crankcase and a linkage that can disconnect the kinematic connection with the piston rod using a rod locking unit and a rod locking control unit. The rod locking unit makes it possible to exclude or allow linear movement of the rod relative to the rotating crankshafts, thereby ensuring, respectively, the inclusion in operation or stop of the piston, i.e., cylinder deactivation. The article shows the operation of one of the design options for the mechanism for modular cylinder deactivation. The advantages and disadvantages of such a solution are analyzed. The obtained design of the mechanism for disabling cylinders by stopping the piston in a connecting rod-less engine with a crank-rocker mechanism is promising and can provide a significant fuel saving effect when disabling cylinders

The article discusses the functionality of a mobile diagnostic complex, an equipment that allows detailed analysis of the operation of an automobile engine based on the oscillograms of the engine harness and signals from additional sensors. This equipment complements the capabilities of a scanner or other device that works with an ECM controller over a digital communication line. The convenience of connection, user-friendly interface and a large number of requested parameters in most cases allows you to solve tasks exclusively with the help of equipment connected to the diagnostic connector of the car. Even when working with the presented diagnostic complex, when the capabilities of the scanner are insufficient, it is advisable to receive some of the information from the car via a digital communication line. Additional pressure sensors in the cylinder, combined with spark plugs or incandescent lights, and accelerometers significantly expand the capabilities of the diagnostic complex. The software of the complex makes it possible to calculate the indicator torque and indicator operation when processing the signal of the standard DPKV and indicator diagrams together. The article also provides examples of the use of the diagnostic complex when performing in-depth diagnostics and conducting research work on internal combustion engines.

When engine cylinders are switched off at partial loads, the engine fuel consumption is significantly reduced, however, there are a large number of unresolved issues that prevent the creation of such an engine. The paper solves the problem of optimizing the operating mode of the cylinder shutdown mechanism in an engine with a crank-and-rocker mechanism for converting piston motion when the hydraulic drive of the mechanism is fed from the engine lubrication system. To ensure controllability of the cylinder shutdown process, the dependences of the angular velocity of the piston rod rotation on the engine speed mode are obtained using optimization and simulation methods. The obtained data made it possible to minimize dynamic loads in the cylinder shutdown mechanism under rational process control conditions. The results are based on a numerical experiment performed in accordance with optimization algorithms and can be used in the cylinder shutdown control system.

The article is devoted to the development of an algorithm for determining ignition gaps based on the signal of a standard crankshaft position sensor. Ignition failures are one of the main reasons for the deterioration of the environmental characteristics of the engine, reduced dynamics and fuel efficiency of the car, failure of the catalytic converter. Timely detection and informing the driver is an important and urgent task. The crankshaft of the engine is an integrating link that senses torques from all acting forces, therefore, its angular velocity and acceleration reflect the flow of the working process in the cylinders. In order to optimize production costs, it is logical to use the signal of a standard crankshaft position sensor with appropriate mathematical processing to detect combustion disorders. Depending on the engine operating mode, ignition failures have a different effect on the dynamics of the crankshaft. An additional complication in solving the problem under consideration is the displacement of the center of the incremental wheel relative to the axis of rotation of the shaft.

In accordance with the key directions of development, including the Concept of the development of the gas engine fuel market in the Russian Federation, Energy and Environmental Strategies, JSC Russian Railways, together with machine-building holdings, is actively involved in the creation of transport equipment using natural gas as motor fuel. A key feature of the power plants of gas-thermal locomotives is their creation on the basis of diesel analogues, just as it was done 30 years ago on the first prototypes. An analysis of the design features and basic technical characteristics of such engines allows us to conclude that there is insufficient elaboration of bottlenecks that occur when transferring transport diesel engines to work on the gas-diesel cycle. This article examines the causes of unstable operation of diesel-diesel power plants of diesel locomotives at low loads and idle, and theoretically substantiates the possibility of quantitative regulation of the volume concentration of gas in the engine cylinders by disconnecting part of the cylinders to ensure guaranteed ignition of the mixed fuel, taking into account restrictions on torque, maximum exhaust gas temperature and maximum combustion pressure of the cycle.

The composition of brake pads friction layer plays  the key role in ensuring the parameters of brake systems specified by manufacturers. It is known that brake pads are subjected to significant mechanical and thermal loads, which leads to their gradual wear, and most importantly, to a change in the coefficient of friction between the disc and the friction layer. The purpose of these studies is to investigate and evaluate the effect of various components of the friction layer on the wear resistance and heat resistance of brake pads. The results obtained will make it possible to optimize the composition of brake pads in order to increase the efficiency of brake systems, as well as to increase their durability.

This article discusses the main methods of protecting products made of composite materials from bio-damage. A patent analysis of modern developments in this field has been carried out. An assessment of the composition, application areas and prospects for the use of various dispersed fillers while ensuring the resistance of polymer composite materials to biological damage has been carried out.

The article examines the verification of the hypothesis that trajectories with lower power levels are characterized by a smaller angle between the linear velocity vector of the coordinate system and a larger diagonal of the manipulability ellipsoid during movement along this trajectory. The concepts of configuration and workspace and mapping between them based on the Jacobi matrix of the excavator are considered. The analysis of hydraulic system power costs in the formation of laws of motion of excavator equipment in the workspace using cycloids, straight lines, chain lines, spatial curves based on B-splines is carried out, and  is also considered the formation of the law of motion in the space of generalized coordinates based on the S-curve technique. The main mathematical models used are shown. The calculations were carried out using the developed software package. The composition of the experimental setup and the methodology of the experiment are given.  Based on the analysis of theoretical and experimental data, conclusions are drawn about the characteristics of the least energy-intensive trajectories.

The article analyzes technologies for cleaning the runway from rubber rolling, special attention is paid to the water jet method, which has proven itself to be one of the most profitable and effective. The process of accumulation of rubber plaque and its impact on the safety of air transportation is considered. The effectiveness of water purification is evaluated in comparison with traditional mechanical methods and chemical solutions, which allows us to identify the advantages of the water jet method, including minimizing damage to the runway surface and environmental cleanliness. The article also includes an assessment of the costs and time resources required to implement the chemical method, as well as consideration of practical examples of its application at various airfields. The authors of the article concluded that the most effective cleaning methods for Russia are shot blasting and water jet methods. The article will be useful to specialists in the field of aviation security and airfield management.

The article proposes to determine the number of construction machines and vehicles when developing construction organization projects, taking into account the output of equipment for maintenance (maintenance) and repair. To do this, it is provided for the estimated period of use in the construction of each machine to set the dynamics of changes in the probability of its working condition over time and coordinate the schedule of construction work with the schedule of maintenance and repair of machines. For Liebherr L556 single-bucket front loaders, the dependences of the failure rate parameter on operating time, as well as the probability of failures between two adjacent maintenance units in the conditions of failure elimination by maintenance services, have been established. The results obtained can be used to justify the number of workable machines and means of transport in construction projects.

The article considers methodological approaches to solving the problem of substantiating the operational properties of road trains with modular trailers for the transportation of bulky and heavy loads (KTG). It is proposed to combine proven methods of qualimetry with mathematical modeling. When calculating the integral indicator of the operational properties of road trains, it is provided to determine the weighting coefficients of individual properties either by one of five or by a combination of the following: regression analysis of the indicators, by target cost functions, by limited and nominal values of indicators, by equivalent ratios and by expert method. The suggested mathematics model presumes safety of transportation as target function, and the other properties are presumed limitations.

The work is devoted to the design of devices for heating or cooling fuel transported by mobile fuel tankers. The relevance of the use of such machines is due to the need to ensure high-quality transportation of fuel and maintain the required microclimate.

This article examined a device for maintaining a microclimate and a basic chassis for its placement. A 3D model of a fuel tanker has also been proposed. Fragments of the methodology for calculating the required characteristics are given. Conclusions and suggestions for use.

The present study is devoted to the analysis of peculiarities of design of braking system of racing cars on the example of Formula Student class racing car. The rationale of the study is based on the need to optimize the design of braking systems under conditions of high loads and requirements of racing competitions. The purpose of the work is to gain an understanding of the design of a bolide brake system and to identify the features that distinguish this process from the design of other sports and civilian vehicles. The study includes design analysis, justification of brake mechanisms selection and simulation results in ANSYS program using finite element method. The results revealed the characteristics of the design of braking systems in racing cars, such as: the importance of the layout of the car, the individual approach to design and the balance between efficiency and safety. The study aims to contribute to the development of racing industry technology and improve safety in an ever-evolving motorsport environment.

This article presents a study conducted in connection with the need to improve the maintenance processes of the VOLVO-FM ATZ-14 car, which is a key aspect of ensuring its efficient and safe operation. The purpose of the study was to identify the most problematic elements of the current maintenance process and to develop a technological map that contributes to the optimization of these procedures. also assessing the risks associated with the operation of special equipment. Key results show a significant reduction in maintenance time and a reduced likelihood of accidents. The relationship between improved service parameters and increased operational safety confirms the correctness of the proposed solutions. The conclusions of the article emphasize the importance of implementing the developed flow charts to ensure long-term and reliable operation of equipment. These results are of interest to specialists in the field of logistics and maintenance of vehicles.

Accident statistics show that the reason for a large number of accidents is the wrong turn speed chosen by the driver. The solution to this problem can be a driver assistance system that will inform the driver about exceeding the speed limit. However, in order to implement this system, it is necessary to know the critical speed of the car on the skid, which, in turn, depends on the turning radius and the coefficient of transverse adhesion of the wheel to the road surface. It is difficult to obtain this coefficient, because different authors propose different ways of calculating and experimentally determining it, which leads to different results in calculating the critical velocity. The article discusses methods for determining the coefficient of transverse adhesion and selects the most appropriate method from the point of view of risk theory. The dependences of the critical speed of the car on the turning radius and the coefficient of transverse wheel coupling are given, taking into account the risk theory for the permissible values of the risk coefficient.

The article discusses a vehicle condition monitoring device, which allows for the assessment of various parameters of the engine and other systems. A general description of the device and its components is given, among which the main one is the microchip.

The paper describes the purpose of the microchip, shows its appearance, proposes a block diagram of the monitoring algorithm and proposes software for monitoring the condition of the car. An algorithm is shown that directly detects faults and transmits them over a remote channel. Functions are presented with the help of which engine parameters are monitored, vehicle systems are controlled, and faults are detected.

A car equipped with an electronic device will have an extended service life due to timely detection of faults, which will avoid problems associated with the failure of units and components.

In this article there are analyzed methods of regulating the road transportation market. The main focus is on opening road transportation market in the EAEU by allowing partial road cabotage to foreign carriers. Studying the experience of EU countries has shown that this issue remains relevant for more than 10 years after the introduction of cabotage in these countries. It is concluded that in order to maintain the competitiveness of Russian carriers in the domestic market, it is necessary to continue working to equalize the working conditions of EAEU carriers: the tax burden, salary levels, conditions for the purchase of vehicles as well as monitoring compliance with the conditions for the implementation of cabotage by foreign carriers.

The development of modern cities requires a change in approaches to the modernization of transport systems. The proven synergy between mass passenger transport and non-motorized mobility is at the heart of these approaches. However, in the field of non-motorized mobility, there is still no clear terminology and classification of devices used to facilitate and accelerate the movement of people. The article examines the existing classification systems for such devices and suggests a variant designed for a generalized classification of vehicles and types of mobility in the traffic regulations. The developed vehicle classification system is supported by appropriate terminology and definitions. Based on it, the directions of improving the traffic regulations and related legislation are determined.

The article discusses controversial issues related to the assessment of the level of localization in the Russian automotive industry, due to the Concept of the development of technological sovereignty of the state. It is shown that national projects to ensure technological leadership determine the need to review the export-import relations of the Russian Federation. Priority directions of the country's socio-economic development have been identified. The transition to long-term economic growth through structural transformation and adaptation of the Russian economy to an increase in production volumes is stated. Comparative parameters of the models of technological globalism and technological localization are given. The contradictions that arise in the context of the implementation of import substitution programs are revealed. It is proved that the innovative development of the automotive industry is associated with research and development work. The methodology of the study is based on a systematic approach to assessing the current state of the automotive industry in Russia and determining its role in the macroeconomic environment. Comparative, analytical, and economic-statistical methods were used in the work to ensure the validity of the results and conclusions. The authors have substantiated the possibility of forming a production program by automotive enterprises, taking into account market dynamics, which is simultaneously influenced by subjective consumer preferences and macroeconomic indicators. The logical result of the study is the conclusion that technological localization will ensure sovereignty in the field of road transport and strengthen the economic security of the country.

In this article, the author reveals the negative effects of sanctions on Russian and foreign students and teachers, including restrictions on access to educational resources, financial difficulties, and difficulties with visas. The potential of cooperation between the BRICS countries to overcome these negative consequences is highlighted. The focus is on developing new strategies and approaches to global learning that will strengthen academic ties between the BRICS countries, provide access to high–quality higher education for students from all participating countries, and promote the development of joint educational programs and research projects. The article examines examples of successful cooperation in the field of education within the framework of the BRICS, and also offers recommendations for further strengthening this cooperation in the context of geopolitical instability.

The article examines the most important categories of the science and academic discipline "Political Science": political power, society, civil society, political democracy, social communications, individual rights and freedoms, imitation democracy, post-totalitarian society, individual sovereignty. The author defined the purpose of the article as an attempt to identify the main reasons for restraining the process of development of institutions and mechanisms of civil society in the Russian Federation and the CIS, to show the difficulties and contradictions of the process. The objectives of this article are the following aspects: characterization of the general state of societies of the CIS countries in the 1990s, post-Soviet societies of the 2000s, highlighting the trends in the formation of the initial elements of civil society, public initiatives and institutions, non-governmental organizations and new communications of citizens with the authorities. The main difficulties in the development of the entire system of civil society are highlighted: institutions, communications, regulatory framework, mechanisms for expressing the interests of society. The article clarifies some aspects of the main categories of the topic, considers the positions of different political scientists, uses empirical material.