The article describes methods for determining soil density, such as the cutting ring method, radiation methods, volume-weight and the method of trial dynamic loading of soil, and a brief comparative analysis of these methods for controlling soil compaction is carried out in order to determine the most accurate and effective of them. Various instrumental implementations of the control methods under consideration were considered, which provide maximum measurement accuracy and automate the determination of soil density, such as a gamma densitometer, a neutron moisture indicator, a rigid stamp, and a densitometer. The most accurate and effective methods from those considered were selected.

In this paper, the authors consider the problem of temperature segregation of the asphalt mix. The work is relevant because the uneven heating of the asphalt concrete mixture affects the quality of the newly laid road surface. The aim of the work is to determine the temperature parameters of the modernized working equipment of the asphalt paver. The paper reviewed the existing equipment of road-building machines and identified their advantages and disadvantages. Based on this, the authors developed a modernized design of the working equipment of the asphalt paver, simulating the heating process of the asphalt concrete mixture, and conducted an experiment.

In the course of the study, the parameters of the modernized equipment were experimentally determined and compared with the parameters of the existing equipment. The experiment was carried out in real conditions using a set of measuring equipment. Three series of experiments with ten measurements were carried out.

The motor grader is a versatile earthmoving machine that has its drawbacks, one of which is stability during operation. This disadvantage is manifested in the process of profiling slopes and during snow removal on slopes of roads, which leads to rolling of the machine or its overturning. This article offers a variant to increase the longitudinal and transverse stability of the motor grader by installing a new type of wheel, which allows you to increase the coefficient of traction with the surface. This wheel allows you to increase the coefficient of traction with the surface due to its transformation from the standard round shape to a triangular track. Advantages and disadvantages of the new wheel in comparison with the standard one are considered. Calculations of limiting angles for both variants of wheels on different types of surfaces and a comparative analysis of the transformed wheel with the standard one, which showed the effectiveness of the developed design.

Around the world, various machines are intensively used, the operation of which is provided by the internal combustion engine. One of the most common types of wear is frictional wear. In order to increase the resource of machine parts operating under constant heavy loads, protective anti-friction coatings are applied to their surfaces, which reduces the downtime of equipment during repairs and maintenance. Anti-friction coatings can consist of a variety of materials and are applied to the part in various ways, as a result of which it becomes necessary to compare them. This article provides a comparative analysis of methods for applying a protective anti-friction layer on various parts of machines and mechanisms. As a result, the advantages and disadvantages of various types of protective coating application are presented.

The article discusses the current safety indicators of users of personal mobility equipment (SIM), as well as methods of protecting their life and health in traffic conditions. In recent years, these vehicles have been gaining more and more popularity in our country and the number of people using them is growing. However, in this regard, ensuring their safety is becoming an increasing problem. SIM users belong to the category of vulnerable road users, because getting into an accident turns out to have much more serious consequences for them than for motorists. The causes of accidents can be subjective and objective. It is most expedient to deal with the former by increasing the general level of driving culture and improving the rules of the road. To combat the latter, it is necessary to apply special engineering solutions or use personal protective equipment.

In the article, based on the analysis of age, environmental class and changes in the requirements for the toxicity of exhaust gases of fire engine engines during certification, a concept is proposed for providing them with an acceptable environmental risk in places of application. The concept is supported by theoretically and experimentally substantiated original technical and technological solutions for the integrated use of diagnostics of failures (malfunctions) of the engine and its fuel system based on the variable composition of exhaust gases, water-fuel micro-emulsions of diesel fuel stabilized by surfactants, and oxidative converters of the block designs with a platinum catalyst. Failure diagnostics is based on empirical relationships between the critical parameters of the fuel system and the smoke and gas composition of the exhaust gases. It is shown that the proposed solutions increase the toxic safety of fire engine engines by two environmental classes.

This study is devoted to the analysis of current world-wide practices of carbon regulation and is aimed at exploring the possibilities of their application in Russia. The key task is to identify appropriate mechanisms for the road sector. The main conclusions are that, firstly, carbon regulation in the road sector requires an integrated approach, taking into account the development of the industrial and energy complexes, as well as sustainable mobility of people and goods. Secondly, the use of carbon regulation mechanisms is a necessary measure to achieve the GHG reduction targets at the global and national levels. The choice of a carbon regulation mechanism should correspond to GHG reduction targets for fight against climate change and reflect the willingness of the relevant jurisdictions, i.e. States, Subnational entities and international organizations to reduce emissions.

The effect of small additions of free hydrogen on the fuel efficiency and environmental characteristics of an automobile engine running on liquefied hydrocarbon gas has been experimentally studied. The VAZ-11194 engine, in-stalled on the test bench, was equipped with gas-balloon equipment with distributed injection of liquefied gas into the intake manifold branch. Hydrogen was supplied to the engine intake tract in front of the air filter. The influence of hydrogen additions on the course of the combustion process is analyzed on the basis of indexing data performed using Kistler candle sensors. The content of carbon monoxide and unburned hydrocarbons in the exhaust gases was measured with an ASCON-02 gas analyzer. Experiments have shown that, just as in engines running on gasoline or natural gas, small additions of hydrogen have little effect on fuel consumption and lead mainly to a reduction in emissions of toxic components with combustion products. Hydrogen additives most significantly affect the content of carbon monoxide in the exhaust gases of an engine. The presence of free hydrogen in the air-fuel mixture, which has a high chemical activity, is reflected in the kinetics of chemical reactions occurring during fuel combustion, including the kinetics of dissociation reactions. The decrease in the concentration of unburned hydrocarbons in the combustion products with the addition of free hydrogen is associated, to a large extent, with a decrease in the volume of flame extinguishing zones in the combustion chamber of the engine.

Today, electric vehicles are the most widespread among vehicles powered by alternative energy sources. During the operation of the electrical components of the vehicle, a large amount of heat is released, so it becomes necessary to use cooling systems to maintain the required temperature range of the electrical components. Computer simulation makes it possible to carry out studies of various processes in vehicles with high accuracy at lower material and time costs. The main purpose of the presented work is to increase the efficiency of heat dissipation of the radiator of the cooling system during fan operation by increasing airflow when changing the distance between surface of radiator and fan. The results of computer simulation and full-scale experiment to determine the optimal distance between the radiator and the fan at different speeds are presented. As a result of the study, it was found that when the casing with the fan was removed by 10 mm from the radiator, compared to the original version, the air consumption increased by an average of 13%. The results of computational studies were confirmed by experiment.

The results of a study of a promising design of a coolant purification module for heavy transport equipment engines are presented. The developed module is a section of a large diameter pipeline (50 mm or more), which has a bypass channel with a hydrocyclone filter separator installed in it. Based on the results of computer modeling of the mock-up version of the purification module, it was decided to introduce special deflectors of a special shape into the design before the bypass channel branch in order to force the flow of liquid into the bypass branch (into the filter separator). The results of the study showed that the hydraulic resistance of the module is very insignificant (does not exceed 6 kPa at a flow rate of 600 l/min), which is a consequence of the bypass layout of the hydrocyclone filter separator relative to the main pipeline. It was also experimentally determined that the trapping capacity of the purification module during repeated passage of liquid through a hydrocyclone filter separator is almost close to 100% for test particles of about 100 microns in size at a flow rate of 500 l/min. The influence of geometric parameters of deflectors in the module channel directing the liquid flow into the hydrocyclone filter separator was also investigated by calculation and experimentally. The developed design of the cleaning module can be successfully applied to engines of heavy transport equipment - mainline tractors, diesel locomotives, river vessels, etc.

The actual direction of achieving the required environmental performance of internal combustion engines is the use of alternative fuels. Vegetable oils and fuels based on them are considered as promising alternative fuels for diesel engines. To ensure acceptable properties of such biofuels, vegetable oils are usually used in a mixture with petroleum diesel fuel. The article examines a mixture of 90% by weight of petroleum diesel fuel and 10% sunflower oil. To improve the quality of the diesel engine workflow, 1000 mg/l of carbon nanotubes from Timesnano (China) were added to this mixed biofuels. To assess the quality of atomization of these mixtures in diesel engines, a simulation of the process of atomization of these fuels into a constant volume chamber using the Converge CFD software package was carried out. The results of the calculated studies showed that the addition of 90% of petroleum diesel fuel and 10% of sunflower oil of carbon nanotubes to the mixture leads to an increase in the diameter of the droplets of the sprayed fuel, which contributes to a certain increase in the length of the sprayed fuel jets. At the same time, this is accompanied by a slight increase in the angle of the cone of the jet opening. It should also be noted the better evaporation of motor fuels when carbon nanotubes are added to them. These effects provide better quality of fuel atomization and mixing processes.

One of the ways to expand the fuel base for autotractor diesel engines is the use of alternative fuels of vegetable origin. Especially promising is the use of vegetable origin fuels as additives to petroleum diesel fuel. Modeling of the working process and, in particular, the injection process, of diesel engines operating on mixtures of petroleum diesel fuel with fuels of vegetable origin, allows us to evaluate the performance of the engine on such fuel and the need to change the adjustments of the fuel equipment. For modeling these processes, it is required to know the compressibility of mixed fuels. Experiments were carried out to determine the compressibility of petroleum diesel fuel with palm oil. To determine the compressibility, a method based on measuring the speed of sound in the fuel in the injection pipeline was used. The possibility of determining the compressibility not only on the basis of measuring the velocity of propagation of a pressure wave, but also on the basis of measuring the velocity of propagation of a rarefaction wave is investigated. It is shown that with an increase in pressure and the proportion of palm oil in the mixed fuel, the speed of sound increases, and the compressibility decreases. To take into account the indicated differences in the compressibility of fuels based on mixtures of palm oil and diesel fuel when calculating fuel supply processes in diesel engines operating on these mixtures, an approximating equation was proposed to determine the true compressibility coefficient based on polynomials of the second degree.

Power and dynamic indicators remain the main indicators of piston engines. At the same time, the dynamic qualities of the car are largely determined by the shape of the external speed characteristics of the engine. The possibilities of changing the shape of the external speed characteristics of the engine by adjusting the fuel supply in these modes are considered. A method is described for improving power and dynamic performance by converting a four-stroke engine to work on a two-stroke cycle in modes with low rotational speeds. The analysis of the results of computational studies of transient processes of engines with different forms of external speed characteristics is carried out. Using the mathematical model developed by the authors, a simulation of the transient acceleration process of a KamAZ-740 engine in the engine speed range from 800 to 2200 min-1 (an increase in the speed mode by 2.75 times) was carried out when adjusting the fuel supply. It is shown that an increase in the fuel supply of a KamAZ-740 engine in the maximum torque mode by about 1.5 times (an increase in the torque adaptability coefficient from 1.05 to 1.50) reduces the engine acceleration time from 8.2 to 5.4 seconds (by 34%). The simulation of acceleration of a car with a 2/4 Sight engine carried out by Ricardo (with its transfer to a two-stroke cycle at speed modes lower than the maximum torque speed mode) showed that when the vehicle was accelerated from 80 to 120 km/h (an increase in the speed of the car by 1.5 times), the time of such acceleration was reduced from 8.1 to 6.7 seconds (by 17%) compared to a car with a standard configuration.

RETRACTED ARTICLE

Increasing the efficiency of the gas distribution mechanism (GDM) with a traverse of medium-speed diesel engines is of great practical importance.

The design of the mechanism links should ensure both the reliability of the valves in the entire range of speed modes and loads encountered during engine operation, and the durability of all parts without complicating the design.

The article presents the results of the calculation of the elements of the GDM with a traverse, recommendations are given to improve their performance. The calculation of the stress-strain state (SSS) of the contact pair "plate-crackers-valve stem" of a medium-speed engine FT26,5/31 was carried out.

Calculations are made for the valve group of inlet valves, taking into account the greater mass and, accordingly, the large forces of inertia of the valve. An analysis of the SSS of the initial version of the designs of crackers, plate, valve and modified designs of these parts was carried out. As a result of the calculation of the stress-strain state of the valve group with a modified design of crackers and valve discs, a significant reduction in maximum stresses with their more uniform distribution over the surface in the maximum power mode has been obtained.

The paper analyzes and selects methods for modeling the design and workflows of a new connecting rodless internal combustion engine with a crank-rocker mechanism and cylinder deactivation. Some results obtained at this stage of the study are shown. The created simulation models made it possible to conduct preliminary studies, debug the methodology for applying the model experiment, evaluate the course of individual processes and determine the speed of the cylinder shutdown mechanism, as well as make changes to the design of some engine components. The presence of simulation models allows you to optimize the parameters of the mechanisms and engine systems at different design stages. The obtained artificial neural networks with high accuracy recognize the mode of turning off the cylinders. The chosen methodological approach makes it possible to obtain a top-level simulation model for evaluating the efficiency of the developed engine and developing a control system.

Тhe main directions of development of modern power engineering industry are increasing power, improving economic and environmental performance with high reliability of the engine. One of the main components affecting both the reliability of the piston engine and the power and economic performance is the cylinder-piston group. The article presents the piston skirt design methodology aimed at developing a design that provides a predominantly hydrodynamic mode of friction in the "piston skirt-cylinder" conjunction. Studies of the hydrodynamic parameters in the conjunction were performed taking into account the deformations of the piston skirt from hydrodynamic pressures and thermal loading, as well as the peculiarities of the secondary movement of the piston skirt. Computational and experimental studies were carried out using the ANSYS software package, the programs developed by the authors and the test stand. The results of studies performed for the two-piece piston skirt of a diesel engine piston are presented, on the basis of which, for the investigated skirt design the profile that provides mainly hydrodynamic lubrication in conjunction "piston skirt - cylinder" is proposed.

One of the modern directions of achieving the required indicators of toxicity of exhaust gases of diesel engines is the use of mixed and emulsified biofuels. The article discusses the possibility of using rapeseed oil as fuel, as well as an emulsion of 70% rapeseed oil by volume with 30% ethanol. Computational studies of the flow of these fuels in the atomizer using the Ansys Fluent software package have been carried out. The stationary flow of the specified fuels into the sprayer of a diesel nozzle of the FDM-22 type manufactured by the Noginsk Fuel Equipment Plant with a sprayer of the Altai Precision Products Plant was simulated. The sprayer had five spraying holes with a diameter of 0.35 mm. At the same time, the pressure at the entrance to the design area was 51.5 MPa, and the back pressures were 0.1 and 8.9 MPa. It is noted that the emulsification of rapeseed oil with ethanol changes the properties of the fuel and the cavitation mode in the nozzle sprayer, which significantly affects the flow parameters in the sprayer. With both considered injection back pressures, the highest fuel flow velocity at the outlet of the spray hole is petroleum diesel fuel, the average is emulsion, and the lowest is rapeseed oil. With a back pressure of 0.1 MPa, the highest kinetic energy of turbulence at the outlet of the spray hole is noted for rapeseed oil, the average is for the emulsion, and the lowest is for diesel fuel. At a back pressure of 8.9 MPa, the kinetic energy of turbulence in the three fuels under consideration turned out to be commensurate, but its greatest value was noted for rapeseed oil.

The article presents the results of a scientific study aimed at studying the issue of rational regulation of hybrid-type automobile power plants containing internal combustion engines and electric machines. The authors propose particular and complex criteria for evaluating the efficiency of the workflow, both in stationary and in a complex of transient modes of operation of hybrid power plants (HPP). A corresponding technique for numerical simulation of the working process has been developed. Mathematical models of the characteristics of the units are compiled, including the partial speed characteristic of the internal combustion engine, the mechanical characteristics of electrical machines and the characteristic of the differential distributor. A technique for optimizing the regime parameters of the HPP for a given mode of movement of an automobile vehicle is proposed. As an example, for a serial HPP P610 of Toyota Prius 2015 model year automobile vehicle, an assessment was made of the efficiency of the workflow under given driving conditions: the main properties were calculated, recommended values for the power utilization factors of each of the engines were proposed, recommendations were given for choosing the modes of the HPP and its components.

The article discusses the issues of fundamental changes in approaches to planning of urban transport systems. The reasons for the insufficient effectiveness of decisions taken within the framework of urban transport policy are analyzed. A critique of traditional transport planning focused on improving mobility is presented. It is noted that "accessibility" as the goal of cities` formation can be achieved not only by improving the transport system, but also by improving land use and urban planning solutions, changes in the ways of providing services in such areas as trade, health, education, etc. The issues of quantitative assessment of accessibility in urban environment are considered. The approaches to the formation of quantitative accessibility indicators which can be used in urban and transport planning are described. A comprehensive accessibility indicator is proposed based on the use of a gravity model of transport behavior with the inclusion of an impedance function that takes into account the assessment of the quality of services of various modes of urban transport. 

An analysis of the problem of adapting supply chains in a modern environment shows the need for a change in the use of the principles of security and fault tolerance of systems, the transformation of models and supply chain management systems (SCM) towards a balance between reliability and flexibility, between efficiency and complexity. The purpose of the article is to formulate new principles and methods of proactive management of an organization according to the criterion of «acceptable risk» at all stages of the life cycle as a whole. The article explores new methods for the formation of an integrated SCM methodology, as a complex organizational and technical system (COTS), based on enterprise engineering, an integrated architectural approach, risk forecasting and proactive management in a high uncertainty environment. The scope of risk management and forecasting should be extended to the entire integrated supply chain (ISC), including the operation of facilities. The principles and new practices of supply chain fault tolerance have been formed based on the interaction of standard architectures with the organization's processes, a program for ensuring business continuity, which reduces the level of threats and losses.

The purpose of the article is to identify the features of the educational activities of technical university first-year students in the study of the discipline "Physics". Authors analyze the results of students intermediate attestations (exams) in the discipline "Physics", as well as the results of repeated intermediate attestations and commissions in the 2021-2022 academic year. Results evaluation of mastering the course of physics indicates a critical state, expressed in a growing number of underachieving and, as a result, expelled students. The comparison results of students' examination scores in the discipline "Physics" with the entrance test results conducted at the beginning of training (September 2021) are presented. There was a marked correlation between the two results. Results comparison of two entrance tests in physics conducted in September 2021 and September 2022 is considered. A sharp heterogeneity of initial training in physics in study groups which is critical for the quality of teaching a discipline (module) is noted. In order to preserve the students contingent the university should use the opportunity to conduct adaptation classes in physics.

The article indicates the specifics of the formation of the moral and moral foundations of the personality of the future engineer, which includes, first of all, humanitarian and social responsibility for activities within the framework of his profession. The role of technical universities as an organizer of various events and a creator of a cultural and educational environment that contributes to students' understanding of their responsibility to society and awareness of modern social risks is also distinguished.

The article shows how the process of stagnation of the world economy developed in the XXI century, and also analyzes the measures taken by the state support for economic recovery and ensuring stable economic growth. The growth of the world economy in 2010-2019 was replaced by stagnation in 2020. The COVID-19 pandemic, the deterioration of relations between China and the United States, the emergence of a political crisis in the Middle East and Brexit caused a reduction in trade and investment. Based on the analysis of macroeconomic indicators of European and Japanese countries, the authors believe that secular stagnation is a steady trend of lowering the real interest rate, which leads to a constant gap in GDP and slow economic growth. The most effective way to combat secular stagnation is to increase aggregate demand. Fiscal policy can stimulate the economy through significant public spending, inclusive social programs and the fight against economic inequality. It is proved that it is impossible to approach the potential output during the period of secular stagnation. The logical result of the study was the conclusion that in order to reduce the period of stagnation, it is necessary to develop a state program using the tools of monetary and fiscal policy.

This article presents the results of research in the field of pricing policy in international markets. Many firms would like to become participants in the trading process on international markets. But here it is appropriate to recall the saying: "I want to, but it stings." Even if your product or service is of excellent quality and you could sell them, the success of the transaction will depend on other factors and, first of all, on the pricing policy. Pricing policy is a whole science. In the article, the authors examined the factors that influence pricing. These are political, economic, social, and technological factors. In addition to these factors, it is also necessary to be able to build a pricing strategy. They can be: economy and premium; penetration or low price; skimming; competitor pricing; marginal cost. And another point, according to the authors, is extremely important – the psychology of pricing. In conclusion, the authors conclude that the price of products depends on both internal and external factors.