bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical modeling of the mechanical stabilization of the sub-tie base of railroad tracks in the arctic zone
Authors: Petriaev Andrei , Paramonov Vladimir
Published: April 2023

The practice of construction and operation of railroads in the Arctic zone shows that the greatest share of track deformations occurs in the summer period during the transition of soils of the subgrade from the frozen state to the thawed state. Wetting, freezing-thawing, and vibrodynamic effects of trains have the greatest influence on the properties of clay soils composing the railroad bed. A model of a sub-tie base stabilized by geosynthetic materials is given. The influence of geosynthetic material on redistribution of stresses during thawing and change of shear deformation character is shown.
Use of earthquake-proof foundations in the design of residential buildings for the areas of the northern climate zone
Authors: Ivanova Zhanna , Filimonov Daniil
Published: April 2023

The regions of the Far North and the territories equated to them today have a great potential for development, which is primarily due to the presence of rich natural resources, among which are unique resources of hydrocarbon raw materials, the development of which directly affects the prospects and directions of development of fuel and energy complex and related industries, which in turn requires the development of several support facilities for various purposes, without which the existence of any enterprise is impossible The article deals with the constructive solution for the construction of urban buildings adapted for specific natural and climatic conditions, as well as the conditions of joint manifestation of permafrost and seismic impacts of high intensity. The technical result is achieved by reducing the effect of seismic loads, by developing elements of special stationary seismic protection (seismic insulation), representing a system with a seismic insulating sliding belt, which is mounted between the heads of piles and the building rostrum. The proposed solution makes it possible to increase the seismic resistance of buildings erected on a soil base according to the first principle by reducing the impact of the stresses arising in the structural elements.
Study results of a stress-strain state of a pylon station construction from monolithic reinforced concrete in the engineering and geological conditions of St. Petersburg
Authors: Kavkazskiy Vladimir , Olenich Dmitriy , Tukmakov Ruslan
Published: April 2023

In recent years, structures made from monolithic reinforced concrete have been increasingly developed in the field of underground construction. This has been made possible by the development of modern tunneling technologies such as NATM and ADECO&RS, which have proven themselves abroad. Being low-sedimentation methods of underground structures construction, they have found wide application not only in mountain transport tunneling but also in construction in an urban environment, where precipitation and negative impact on the surrounding infrastructure has a decisive role in the choice of one or another technology. Foreign experience of construction in the same physical and mechanical characteristics of soils gives reason to assert the possibility of using new technologies in our country. However, this task requires a comprehensive approach to its solution. This article presents an experimental and theoretical substantiation of a pylon station lining made from monolithic reinforced concrete in the engineering and geological conditions of St. Petersburg on the example of the planned St. Petersburg Metro station “Chernigovskaya” of the “Krasnoselsko-Kalininskaya” line being built from “Obvodniy Kanal-2” station to “Yugo-Zapadnaya” station.
Year-round thermal stabilization of permafrost soils during road construction in the northern climatic zone of Russia
Authors: Moiseev Vladimir , Komarova Tatiana , Petryaev Andrei
Published: April 2023

The device for year-round cooling of permafrost soils is designed to ensure the construction and operation of roads and railroads in the tundra zone. It includes pipes buried in the ground near the roadbed, a wind turbine powering an electric current generator, an absorption-type cooling unit, and an exhaust fan ensuring the flow of atmospheric air through the pipes. During the long and cold winter, the pipes laid in the ground provide deep freezing of the ground beneath a thick layer of snow. In spring and autumn, at temperatures close to 0°C, the air in the pipes is forcibly cooled by the cooling unit. In summer, at air temperatures exceeding 10°С, air movement through the pipes is blocked. In conditions of short summer, low levels of the sun above the horizon, the high albedo of snow and ice, and their low thermal conductivity, snow deposits remain on the ground throughout the summer period, and in the subsequent winters, accompanied by snowfalls, they intensify. Around a roadway built on permafrost, a protective snow layer is formed, preventing the flow of heat from the atmosphere and solar radiation into the ground. The protective layer can exist for decades, even if the Earth’s climate changes globally. The article presents hydraulic and thermal calculations, explaining the operation of the device in question.
Mathematical model of crossing of discrete snow obstacles
Authors: Makarov Vladimir , Belyaev Dmitriy , Papunin Alexey , Klyushkin Anton , Ruzhev Vyacheslav , Gubarev Vladislav
Published: April 2023

The paper is concerned with research of mobility of vehicles, specifically of flotation. The new definition “discrete flotation” is considered. The subject of moving over the snow road surface is considered, especially the crossing of terrain compartments with varying height of snow blanket. The classification of discrete snow obstacles is given separated by the next features: the occurrence of directed anthropogenic factor, the type of formation source, the structure, the degree of shape uniformity of formation source, the stress-strain properties, the composition and the shape of discrete obstacle. The relation describing the shape of snow drifts is given containing the parameters determining the distribution shape, the scale, the area of longitudinal section and the dimension. The relations intended to determine the resistance to moving when crossing the snow drifts and the condition of flotation loss are given.
Assessment of hydraulic efficiency and duration of residual service life of metal water supply pipelines
Authors: Yakubchik P. , Chernykh A.
Published: April 2023

Substantiation of the necessity to develop projects of reconstruction of non-wood metal water supply pipelines, which have been in operation for a long time, including in the far north regions. Development of methodology of estimation of hydraulic efficiency and duration of residual service life of metal pipes depending on the thickness of the actual layer of deposits on their inner walls. Methods. It is proposed to estimate the period of residual use of steel and gray cast iron pipes by the value of the coefficient of efficiency of their operation. Outcomes. The study allows us to determine the values of the coefficient of efficiency of the use of the pipeline, assembled from steel and gray cast iron pipes, characterizing the residual duration and hydraulic efficiency of its operation. We obtained a formula for determining the coefficient of hydraulic efficiency of metal water supply pipelines, which is the ratio of values of actual characteristics of the hydraulic potential of non-metal pipes at the moment of evaluation to the values of these characteristics for steel and gray cast iron pipes. Practical Relevance. The developed methodology is recommended for use in determining the possibility of extending the period of further use of worn metal water supply pipelines, as well as for predicting the duration of their residual operating life.
The use of intelligent information technologies in the development of managerial decisions during organizational changes
Authors: Bozhko Lesya , Liuniakina Anastasiia
Published: April 2023

In change management, there emerges the problem of making timely and relevant managerial decisions. During the entire process of change, it is necessary to make decisions that ensure the success of changes, which is rather difficult in conditions of insufficient or, otherwise, abundant information and limited resources. The purpose of the study is to explore the possibilities and present the advantages to using intelligent information technologies in change management. The objectives of the study are to identify the features of decisions made during the period of changes; to identify the factors affecting the implementation of information analytical activities, and to review digital technologies that can accelerate decision making and improve its quality in change management. The results of the study have been obtained on the basis of an analysis of trends in the development of the IT market, the data on the introduction of advanced information technologies into company management for the period of 2020-2021, and an expert survey. Taking into account the formulated requirements for managerial decisions during the period of changes, a methodology for using intelligent information technologies in change management has been developed. Within the framework of the proposed methodology, there is established the relationship between the tasks of change management and information support. There is conducted a review of the digital technologies that can be used in managerial decision-making when implementing changes. The results of the study can be used in the development of an information system model that provides support for managerial decision-making during changes in the company.
Sustainable environmental and economic relations of Turkiye and republic of South Africa — a focus study for the period 2000-2010
Authors: Hakan Çora , Hasan Mikail Elnur , Nazmi Çora Ali
Published: April 2023

As one of the primary issues facing Turkiye, environmental degradation is one of the Sustainable Development Goals (SDG). Therefore, a policy-level reorientation may be required to address this situation. Based on this perspective, during the increase of mutual economic developments between Turkiye and South Africa, the impact of renewable energy (RE) use, financial develoment, urbanization, and agriculture emissions of carbon dioxide should be analyzed separately using a dataset spanning a considerable period of time. South Africa develops its national environmental policy through a consultation process known as the National Consultative Environmental Policy Process (CONNEPP). The process is designed to provide an opportunity for all stakeholders in South Africa to contribute to the development of a new environmental policy. With the end of the apartheid period in 1994, the Republic of South Africa initiated a comprehensive program of economic reform and development going forward and made significant progress in many sectors after 2000. At this time, Turkiye, as situated on a strategic location regarding global trade, was expanding its operations worldwide. The purpose of the research is to analyze the Turkish RSA relations focusing on the first decade of 21st century. As a basis of our methodology, we have researched achieves and business records as tangible verifiable information about this time period. Although the global financial crisis of 2008 affected this country for some time; the development line and ongoing momentum in the automotive industry sector, as well as sectors such as construction, banking, investment regulations, energy, telecommunications, mining and agriculture, are worth mentioning. For this specific research article, we believe that it is imperative to focus the 2000-2010 period which is the basis of today's cooperation which will bring a specific value to the academia.
The development of measuring system for studying the dynamic processes of the main brake components in operation
Authors: Yaitskov Ivan , Nazaretov Andrey , Kosarevskiy Valeriy
Published: April 2023

The paper discusses and solves the problems associated with carrying out full-scale tests of the developed accelerometer sensor mounting system in the “lever gear block-wheel” system under operating conditions, including the main problem of measuring shoe and shoe accelerations, which was the impossibility of installing sensors directly on the shoe or block.
Analysis of the market structure of operator companies: methods and evaluation
Authors: Zadorozhniy Vyacheslav , Bakalov Maksim , Demina Anastasiia
Published: April 2023

Analysis of the role of operator companies in the rail freight market in terms of competition and multi-agency is carried out in this article. It emphasizes the importance of choosing competitive strategies and identifying dominance and monopolization of markets. The methods of SWOT-analysis and Porter's analysis are used to assess the competition of operator companies. In addition, the Lind, Herfindahl-Hirschman and market concentration indices are important indicators of competition. Indices were calculated for each segment of the rolling stock. An assessment is given to the rolling stock operating market. Competition assessment results help operators identify their competitive strengths and weaknesses, and take the necessary steps to strengthen their market position.
Parameters of the soil-holding part of the slurry spreader
Authors: Mirzaev B. , Mamatov F. , Abdullaeva B. , Chuyanov D. , Shodmonov G. , Buriyev M.
Published: April 2023

The aim of the study is the theoretical substantiation of the parameters of the soil-holding part of the slitter for manure incorporation into the soil. A slitter with soil-holding part to the tool for application of organic fertilizers was developed. The basic principles and methods of classical mechanics, mathematical analysis and statistics were used in this study. The analytical dependences for determining the parameters of the soil-holding part of the creeper were obtained. The length of the soil-holding part of the creeper depends on the speed of the machine, the angle of installation and the height of the jogger blade, the angle of the natural slope of the soil, the coefficient of friction of the soil and manure, and also their fall height. It is set that at an angle of friction of soil 23-37º, an angle of a natural slope of soil 30-41º and speed of unit movement 1,4 m/s, the length of a soil-holding part is equal 0,15-0,25 m.
Thermodynamics of hydrogen sulfide adsorption in Zeolite Lix
Authors: Abdurakhmonov E. , Sapaev I.B. , Abdullaeva B. , Rakhmatkarieva F. , Dekhkanova N.N.
Published: April 2023

Sulfur compounds adversely affect the technological process of oil and gas refining, as well as the release of sulfur-containing compounds into the atmosphere, polluting the environment. Oil and gas processing is carried out using microporous adsorbents with high sorption capacity in the purification of gases containing sulfur. This is one of the most efficient methods in oil refining and gas processing. In research work, the adsorption of gases containing sulfur in their composition is carried out in various ways. When determining the formation complex, the main centers of Li-ionic molecules, it was possible to obtain a more accurate idea of the adsorption mechanism at the stages of absorption of hydrogen sulfide molecules into Li-zeolites using a highly sensitive adsorption calorimeter. In our study, in the process of adsorption of hydrogen sulfide on the LiX zeolite, the results of differential adsorption heat, isotherm, entropy, and thermal equilibrium time (thermokinetics) based on obtained in a high vacuum adsorption device are accurately revealed. Based on exact formulas, it was proved how many hydrogen sulfide molecules are adsorbed in the zeolite that died under vacuum conditions.
Abrasive blasting of the teeth of linter saws with the aim of their activation
Authors: Ortikov Oybek , Shodmonkulov Zokhir , Kurbonova Oysha , Shin Illarion , Nurbekova Shakhnoza
Published: April 2023

The article presents materials on the effective use of abrasive blasting of the side surfaces of the teeth of saw blades in order to activate them during lightering. The scraping action and cutting of short fibers from seeds is enhanced by microroughnesses of the formed micro profile after impact interaction of an abrasive particle with a metal surface. Using atomic force microscopy, we obtained the height and step parameters of the roughness of the machined tooth surface, which are compared with the transverse dimensions of the cotton fibers, and thus a model for the intensification of the littering process is proposed.
Increase of wear resistance of tribocontact with low-melting metal and porous coating
Authors: Lagunova Elena , Mukutadze Murman , Badakhov Grigory , Zinoviev Nikita , Shvedova Valentina
Published: April 2023

The paper is devoted to one of the most important problems of increasing wear resistance of tribosystems due to the application of low-melting metal and porous coatings on tribocontact surfaces. The asymptotic and self-similar solution for zero and first approximation was found based on the true viscous fluid flow equation for the “thin layer”, equations of continuity, an equation describing the flow of a lubricant in the body of a porous surface coating of a bearing ring; and an equation describing the profile of the molten surface contour of a bearing ring coated with a low-melting metal alloy, i.e. as a result, excluding the metal coating melt and considering the melt the velocity and pressure fields in the lubricating and porous layers are determined; as well as the load capacity and the friction coefficient, which allows determining the increase of wear resistance – increase of hydrodynamic pattern due to porous and low-melting metal coating of contact surfaces of the tribosystem.
New ways of processing and application of the croton fraction of waste from the production of JSC “Navoiazot”
Authors: Kazakov Umrbek , Ibadullaev Akhmadjon , Adkhamova Irodakhon , Kadirov Xasan , Yoqubov Bekhzod
Published: April 2023

The purpose of this work is to study the interaction of the croton fraction with amides – urea and thiourea and to develop technologies for obtaining accelerators for vulcanization of rubbers for the rubber industry.
Multifunctional ingredients for composite elastomer materials
Authors: Ahmadjonov Sardorbek , Teshabaeva Elmira , Akhmedova Makhfuza , Turabdjanov Satridtdin , Abdiraimova Kamola
Published: April 2023

The purpose of this work is to study the effect of multifunctional ingredients on the complex of properties of composite elastomeric materials. New multifunctional ingredients with stabilizing properties are proposed, and their optimal content in the composition is determined. It is shown that thermal aging of composites stabilized by furan oligomers, with an increase in the duration of aging time, a decrease in the relative elongation of the composites is observed, which, in the process of thermal exposure under the action of furan units, additional structuring occurs.The expediency of using furan oligomers as effective multifunctional ingredients for elastomer compositions has been established, which made it possible to purposefully regulate the structural and physico-mechanical characteristics of the compositions without changing the technology and instrumentation of the existing production.
Magnetic properties of soft magnetic composites used in electromechanical engineering
Authors: Berdiev U. , Sulaymonov U. , Abduvalieva D. , Khasanov F. , Berdiyorov U.
Published: April 2023

The article discusses the methods of using composite magnetic alloys for elements of electrical engineering. The main methods of obtaining soft magnetic composite materials have been studied in order to obtain high-performance MMC particles, as it should be subjected to electrically insulated powder to obtain high-density parts. High densities generally improve magnetic properties, both to keep hysteresis losses low and to obtain high flux density. These give an effect when used for the cores of electric motors based on magnetically soft composite materials.
Use of evaporative cooling units in solar air conditioning installations
Authors: Isakhodjayev Kh. , Sultanbayev N. , Kazakbayev J. , Vaditov A.
Published: April 2023

The paper describes the calculation of evaporative-radiant cooling of recycled water in summer air-conditioning systems. A differential equation for the heat balance of water flowing down an inclined plane is derived. As one possible way of increasing the efficiency of air conditioning systems based on cooling water by adiabatic evaporation in the air flow the use of night-time evaporative cooling of the water, followed by daytime cooling in insulated storage tanks. The temperature of the water chilled in this way is 3-4 ℃ lower than the temperature of the water chilled during the day, and the final water temperature is close to the saturation temperature of the outside air. The equations for calculation of mass transfer coefficients, radiation and heat transfer coefficient of an insulated bottom of an evaporative-radiant water-cooling unit are given. Based on the Mathcad program and the result of the calculation, the dependence of the final water temperature on the initial water temperature is obtained. As a result of the calculation, the specific heat capacity of the evaporative radiant water-cooling unit for the production of free cooling is determined.
Photoconductivity of gamma-irradiated Znse (Te)/ZnO:O and ZnSe(Te)/ZnO:O,Zn nanogeterojuctions
Authors: Elmurotova D. , Nishonova N. , Kuluyeva F. , Muxtarova T.
Published: April 2023

Possibility of enhancing the photoconductivity of ZnSe (0.2%Те)/ZnO:O nanoheterojunction was investigated under effect of thermo-treatment in zinc vapor followed by 60Сo gamma-irradiation in air to the dose of 106 Gy by means of generation of impurity-defect complexes. The obtained ZnSe (0.2%Te)/ZnO:O,Zn nanoheterojunction had an electron conductivity with the activation energy 0.33 eV that is caused by thermo-stimulated transfer of charge carriers on the stable resonance level Γ6v= 5.76 eV in the conducting band. The significant photoconductivity growth from 10-10 to 10-5 Ω-1 was achieved at 300 K, and also a broad band (480-1100 nm) light scattering at free carriers occurred due to formation of additional stable associates (OSe0TeSe0VZn-), (OSe0VZn-)- or (OSe0VZnMeZnIIIZni) at the interface between the matrix crystal p-ZnSe(0.2%Te):O,Zn and nanocrystallite n-ZnO of 40 nm size, where amorphous phase layer of 1.2 nm was also grown.
Surface ionization of CsCl molecules in the learning process
Authors: Abdullaev Rakhmatulla , Zakhidova Mavlyuda , Urazimbetova Aygul , Giyasova Zukhra , Begmatova Dilfuza , Suvonova Okila
Published: April 2023

The paper presents the results of studying the catalytic properties of “metal-carbon” systems using the method of surface ionization of CsCl molecules. Using the Ir-C system as an example, it was shown that the poisoning effect of the same poison (carbon) strongly depends on the structure of the layer formed on the catalyst. In metals that do not form bulk carbides, the carbon monolayer completely poisons the catalytic properties of these metals. It is shown that individual atoms and clusters of samarium deposited on iridium coated with a monolayer of graphite lead to efficient catalytic dissociation of CsCl molecules. The mechanism of formation of a carbon film on the surface of a metal obtained by diffusion from the volume, which differs from the mechanism of formation of a carbon film obtained on the surface of a metal by adsorption, has been elucidated.
Optimal ratio of spectrum, light intensity and photoperiod to minimize costs when growing microgreens
Authors: Filatov Dmitrii , Olonin Igor
Published: April 2023

The paper considers the influence of spectrum and light intensity/photoperiod ratio on the energy intensity of production and financial costs of consumed electricity. This influence is caused not only by the yield obtained, but also by the different energy efficiency of lightemitting diodes of different spectrum and the price of electricity at different hours of the day. Considering the influence of the spectrum, it was found that the costs decrease with increasing the proportion of red light for all microgreen varieties under consideration. Laboratory studies were carried out on microgreens of cabbage of the “Mitsuna” variety and radish of the “Octave” variety. A long photoperiod at low intensity is better than a short photoperiod and high light intensity in terms of energy and financial efficiency. Combining the results on dry weight as a quality indicator, energy consumption and financial cost per fresh weight, we consider a lighting system with parameters B:R:FR=29:58:13%, PPFD= 100 μmol·m-2·s-1 / 16 h as the preferred option for growing microgreens.
Lidar sounding of carbon dioxide and water vapor with absorption spectroscopy techniques
Authors: Sadovnikov Sergey , Yakovlev Semyon , Romanovskii Oleg , Nevzorov Alexey
Published: April 2023

A possibility of monitoring greenhouse gases (CO2 and H2O) along horizontal paths in the troposphere with two-channel near-IR lidar system based on an absorption spectroscopy measurement technique is estimated. The main units and components of the IR lidar under development are described. A backscattered signal is simulated in the informative range of IR lidar for sensing target greenhouse gases.
SaaS in digital ecosystem of smart priorities for transport and logistics
Authors: Drozdova Maria , Zarubkina Olga
Published: April 2023

The objective of the article is to provide an analytical overview of the various aspects of the development and implementation of Saas services in the development of a digital ecosystem of smart priorities for transport and logistics as of March 2023, including an analysis of the industry needs for their further development and effectiveness of their use in the context of new geopolitical challenges. Methods: The work applies the method of analytical review of the state of the Russian market of SaaS technologies, the peculiarities of the development of national digital services in the field of logistics, and ways to improve the efficiency of their application.
Atomic force microscopy of anisotropic silicone magnetoactive composites
Authors: Valiev Hammat , Karnet Yulia , Kornilova Alla , Minaev Andrey , Stepanov Gennady
Published: April 2023

New anisotropic magnetically active elastomers using carbonyl iron micrometer size ferromagnetic fillers in the silicone matrix were synthesized. Samples with orientation of the outer magnetic field strength vector applied in perpendicular or in parallel direction to the mold surface during polymerizing composite mass were investigated. These composites surface structure was studied using the topography and phase contrast images in the atomic force microscope. Significant surface magnetodeformation effects in these composites, comparable with Terphenol-D, under the application of small external magnetic fields were visualized by atomic force microscopy methods. The transverse magneto-deformation constant value was determined for both samples. Greatly periodically deformed surface structure background was observed in these composites. The obtained experimental results analysis show that significant component of these materials unique properties is due to the ferromagnetic fillers restructuring in both isotropic and anisotropic magnetically active composites under small external magnetic fields influence.
Experimental research of dynamic vibration damping for rigid busbar structures
Authors: Fomenko Serafim , Garanzha Igor , Tanasoglo Anton
Published: April 2023

Introduction: in the case when flexible structures interact with the wind flow, various phenomena of aerodynamic instability may arise. Typical representatives of such phenomena are vortex wind excitation of cylindrical structures, galloping of poorly streamlined structures with a square, rectangular or rhomboid cross-section, etc. The article highlights some basic ways of damping vibrations of rigid busbar structures. Materials and methods: the method of dynamic vibration damping consists in attaching additional devices to the vibration protection object to change its vibration state. The work of dynamic dampers is based on the formation of force effects transmitted to the object. It differs from another method of vibration reduction, characterized by the imposition of additional kinematic connections on the object such as fixing its particular points. Results: a mathematical model of the plate dynamic damper operation with a point load is presented. To determine the optimal parameters of dynamic vibration dampers, their calculation was performed, taking into account the joint action of the rigid busbar and the damper. Experimental research of the conjoint work of a rigid busbar with a plate dynamic damper is carried out. Conclusions: the effective application of plate dynamic dampers with a point load has been confirmed both outside and inside the tube busbar. Is proposed the special plate vibration damper. This allows to increase the logarithmic decrement of oscillations by 3-3.5 times and reduce the amplitude of oscillations of rigid busbar structures in the resonant mode by 12 time.
Risk management at the stages of the life cycle of NPP projects
Authors: Ashraideh Mohammad , Engovatov Igor
Published: April 2023

The article discusses the issues of risk management at all stages of the life cycle of nuclear power plants. The definition and classification by types of risks that arise during the stages of the life cycle and operation of difficult objects such as nuclear power plants. Risk is anything that has the potential to affect each stage of a facility’s life cycle, performance, longevity, safety, or project budget. Thus, risk management is the process of identifying, classifying, prioritizing and planning risks. This article not only discusses the identification and classification by types of risks that arise during the construction and operation of such complex facilities as nuclear power plants, but also describes the methods for assessing and managing risks, taking into account the specifics of the construction of nuclear power facilities. There are two methods of risk assessment: quantitative and qualitative. The article describes such Quantitative methods as “Scenario Technology”, “Method - Sensitivity Analysis”, “Diagramming Technique - Tree Analysis”, as well as such Qualitative risk assessment methods as “Assessment of the probability of risk and its impact”, “Evaluation Matrix probability/risk of impact”, “Probability and impact”, “Risk classification and assessment of risk urgency. As a result of the analysis of existing risk management methods at all stages of the life cycle, the following conclusions were drawn: Risk identification can occur at any stage of the life cycle of a nuclear power plant, even after completion of construction work and delivery of the project. The maximum number of risks for all stages of the NPP life cycle should be identified at the stage of Sitting and design. The article proposes the format of the risk register table, provides a risk classification scheme, and develops a risk management flow chart at the stages of the NPP life cycle.
Structural changes in steel during hardening by deformation wave
Authors: Kirichek Andrey , Solov’ev Dmitry , Silantyev Sergey , Yashin Alexandr
Published: April 2023

The article presents results of study possibility of hardening of high-manganese steel X120Mn12 by a deformation wave in the process of wave strain hardening (WSH). Features of the method is possibility of using shock waves for plastic deformation, which significantly expands the technological capabilities for formation of a hardened surface layer. The dominant design and technological parameters of the hardening treatment are established, which have the main influence on the microstructure and hardness of the hardened surface layer. Possibility of a significant increase in hardness and depth of hardened surface layer is established. The depth of hardened layer can reach 6-8 mm, and the hardness can be increased by more than three times. Microstructural analysis showed no cracks. The obtained results of conducted research can be used to develop a technology for strengthening the deformation wave of various heavy-loaded parts made of high-manganese steel.
Investigation of the feasibility of using wing struts and non-retractable landing gear struts on a light multi-purpose aircraft
Authors: Kuznetsov D.S. , Tikhtey Y.N. , Kremenchutsky V.V. , Vilesov A.G.
Published: April 2023

In this paper, we consider a method for determining the feasibility of using a wing strut and non-retractable landing gear on a light multi-purpose aircraft. In a certain range of cruising speeds and flight ranges, it is advisable to use non-retractable landing gear and wing strut. With an increase in cruising speed and flight range, these engineering solutions must be abandoned to improve aerodynamic characteristics. The dependencies obtained in this work make it possible to make decisions on the use of a wing strut and non-retractable landing gear at the early design stages. To obtain aerodynamic characteristics in the Siemens NX program, a three-dimensional model of a light multi-purpose aircraft was created and an aerodynamic experiment was performed in the FloEFD program. Then the calculation of flight performance was carried out. As a result of the study, the dependence of the speed up to which it is advisable to use the undercarriage strut and fixed landing gear on the flight range for a light multi-purpose aircraft weighing 2000 kg was obtained. When designing an aircraft, it is necessary to make decisions about the use of one or another engineering solution, which, on the one hand, has a positive effect on aerodynamics and negatively on the weight of the aircraft, and vice versa. In this article, using the example of a wing strut and fixed landing gear in the first version of the aircraft, and a cantilever wing and retractable landing gear in the second version, a model for solving such a problem is shown.
Basic design and technological solutions for the application of automated layout processes in the manufacturing of composite parts of passenger aircraft
Authors: Melkonyan R.V. , Nasonov F.A.
Published: April 2023

Currently, there are great perspectives for the technology of manufacturing products and aggregates from PCM based on prepregs. Thus, the use of prepregs makes it possible to manufacture complex configuration parts in one technological operation. High competition and the increasing necessity of mass production of large-sized parts from PCM determines the emerging need for the use of automated layout equipment. The replacement of traditional, manual methods of layout by automated methods provides significant advantages, such as an increase in the quality of the resulting parts, a significant reduction in labor intensity of their production, an increase in accuracy and repeatability of the technological process of layout (reduction of defects) and, consequently, reduction of the cost of the finished product.
On the issue of reducing the temperature heating of the airframe structure of a supersonic aircraft
Authors: Shiryaev A.V. , Maysak M.V. , Kremenchutsky V.V. , Safin R.M. , Demidov V.V.
Published: April 2023

In this paper, the influence of heating of the structure on its strength is considered in three aspects: a decrease in the mechanical characteristics of structural materials at high temperature, heating of the structure can lead to temperature stresses in its elements and elements of aircraft systems and the occurrence of the phenomenon of creep of structural materials - continuous plastic deformation of structural elements under constant load. There are several options for reducing heat flows due to modification of the basic aerodynamic layout: increasing the sweep angles of the bearing surfaces and the radius of the wing tip and the front edges of the inflows, reducing the area of the washed surface due to the “flattening” of the initial aerodynamic contours. Each of the considered existing and promising methods of thermal protection separately will not allow to fully develop thermal protection of promising reusable supersonic aircraft. A comprehensive approach is needed. At the same time, it is necessary to consider both the replacement of structural materials of panels and cladding with titanium or steel alloys, as well as design solutions for the use of fuel lines.
Transition metal doping and co-doping effect on electronic and magnetic properties of zb-ScN
Authors: Réda Mohamed Amine , Rami Redouane , Drissi Lalla Btissam , Aberdane Ilham , Ahl Laamara Rachid
Published: April 2023

The ab-initio study of electronic and magnetic properties and Curie temperature of transition metal (TM) doped ScN diluted magnetic semiconductor (DMS) are calculated using generalized gradient approximation (GGA) implemented in AKAI-KKR-CPA package. The total and partial density of states (DOS) of pure zinc blend ScN as well as TM doped compounds are plotted for different concentrations of dopants. Our results shows that the Sc substituted by TM materials induces a half-metallic character in the system for different concentrations except for Sc1−xNixN (x > 8%). Also, We found that the Sc1−xVxN, Sc1−xCrxN, Sc1−xMnxN compounds are stable in ferromagnetic states, while Sc1−xCoxN and Sc1−xNixN compounds prefer antiferromagnetic phase. In addition, the minority-spin bands depicted a half-metallic ferromagnetic (HMF) gap and half-metallic (HM) gap. To improve this latest result, doping ScN with double impurities (Co, Ni) is also investigated. As a result, our results show a stable antiferromagnetic state in the majority of cases. The mechanism of exchange interaction is also discussed for all doped systems and the high curie temperature are found for most concentrations. The present results suggest TM doped ScN as potential candidate for spintronic devices.
D’ennemis à amants : la coopération trophique entre S. aureus et P. aeruginosa autour de l’acétoïne
Authors: Blanc Jules , Cadot-Jet Ninon , Deshayes Tom
Published: April 2023

Ce dossier a été rédigé par les étudiantes et étudiants de Master 1 (M1) de biologie de l’École normale supérieure de Lyon à l’issue de l’unité d’enseignement (UE) Microbiologie moléculaire et structurale (2021-2022). Le Master de biologie de l’ENS de Lyon accueille chaque année environ 40 étudiants en M1 et en M2 et propose une formation de haut niveau à la recherche en biosciences. Chaque étudiant y construit son parcours à la carte, en choisissant ses options parmi un large panel de modules, favorisant ainsi une approche pluridisciplinaire des sciences du vivant, en relation étroite avec les laboratoires de recherche du tissu local, national et international.

En participant à diverses activités scientifiques liées aux UE de leur formation, les étudiants préparent également l’obtention du Diplôme de l’ENS de Lyon, qui valide leur scolarité à l’ENS. La rédaction du présent dossier, qui vise à transmettre de façon claire les messages issus d’une sélection d’articles scientifiques publiés récemment par des laboratoires lyonnais dans le domaine de la microbiologie, constitue l’une de ces activités connexes proposées aux étudiants.
Acute Effects of Whole-Body Electrostimulation Combined with
Stretching on Lower Back Pain
Authors: Silvestri Adriano , Ruscello Bruno , Rosazza Cristina , Briotti Gianluca , Gabrielli Paolo Roberto , Tudisco Cosimo , D'Ottavio Stefano
Published: April 2023

Data from recent studies suggest that whole-body electromyostimulation (WB-EMS)
is a time-effective and tailored intervention for chronic lower back pain
(CLBP). The aim of this non-randomized controlled study was to compare the
efficacy of a WB-EMS training and the association between WB-EMS specific
training with passive stretching (Well Back System, [WBS]) on CLBP. Forty
patients with CLBP, 43–81 years old, were assigned to one of the two
groups: WB-EMS (n=20) and WB-EMS+WBS (n=20). Both groups
completed 12 sessions (8 weeks) of the WB-EMS protocol
(2×20 minutes/week). The second group performed
core-specific exercises with WB-EMS plus 6 extra stretching sessions
(30 minutes each). Primary study endpoints were based on changes on the
visual analogue scale (VAS) and changes on the Oswestry Low Back Disability
Questionnaire (ODI). Secondary study endpoints were percentage changes of
maximum trunk flexion (Sit & Reach, [SR]) and changes in consumption of
painkillers. Both interventions significantly improved VAS, ODI, and SR values
(p range: 0.04;<0.001). However, the change of VAS
(–46% vs. –17%, p<0.001), ODI
(–53% vs. –17%, p<0.001), and SR
(+ 7 vs.+3 cm, p=0.001) were
significantly higher in the WB-EMS+WBS group compared to the WB-EMS
group. The working method with WB-EMS+WBS can be a joint-friendly,
individualized form to decrease CLBP.
Peripartum Cerebral Angiopathy
Authors: Sallam Amr , McWilliams Sebastian R. , Boyle Karl , Larkin Caroline M.
Published: April 2023

Peripartum cerebral angiopathy (PCA) is a rare cerebrovascular disorder of unclear etiology that typically occurs in the first postpartum week. The aim of this case series is to present seven cases of PCA and the associated outcomes. Two of the cases were typical of a reversible cerebral vasoconstriction syndrome (RCVS) and had no long-term sequelae. Five of the cases involved intraparenchymal hemorrhage in the absence of an underlying vascular lesion, with three of the five cases having associated cerebral vasoconstriction. None of the patients had a documented history of preeclampsia or hypertension during pregnancy. It has been suggested that there is pathophysiological overlap between PCA and eclampsia and RCVS. There is limited evidence in the literature in this regard and, in most cases, treatment has been supportive only. As a condition, PCA may be under-recognized in the neurocritical care setting. Increased awareness of this condition, its manifestations, and options for management may optimize outcomes.
When Do Patients with Breast Cancer Seek Help from Psycho-oncology Services? A 3-Year Retrospective Study from India
Authors: Mukherjee Arnab , Samanta Bidisha , Sharma Varuna , Shrestha Aagon Krishna , Chattopadhyay Shreshta , Bhowmick Chitralekha , Ghosh Joydeep , Ganguly Sandip , Agrawal Sanjit Kumar , Datta Soumitra Shankar
Published: April 2023

Introduction Breast cancer is the most frequent cancer among women. In the last few decades, the outcome of breast cancer has improved significantly in terms of survivorship and quality of life. However, it is crucial that alongside managing the disease, breast cancer services address and manage associated or co-occurring psychiatric illnesses such as acute stress reactions, procedural anxieties, adjustment issues, depression, and fear of recurrence, which leads to an overall better experience of the patient.

Objective There is a paucity of data on the patterns of psychiatric morbidity in patients with breast cancer who access psycho-oncology services in a naturalistic setup outside research studies from India. The current study focused on exploring this alongside reporting the common treatment methods adopted for this group of patients.

Materials and Methods Real-life data from electronic patient records were retrospectively reviewed for all patients with breast cancer accessing integrated psycho-oncology services in a tertiary care hospital in India over three 3 years (2018–2020). The various psychiatric morbidities were reported, along with associated cancer demographic data, disease characteristics, and treatment details.

Results Of all the breast cancer patients (n = 338) in the calendar years 2018 to 2020 reviewed by psycho-oncology services, the most common psychiatric diagnosis was depressive illness (n = 100, 29.6%), followed by adjustment disorders (n = 68, 20.1%) and anxiety (n = 66, 19.5%). There was a significant minority with serious enduring mental illnesses such as schizophrenia (n = 11, 3.3%) and bipolar disorders (n = 14, 4.1%). On the other hand, 14.2% (n = 48) of the patients with breast cancer who attended Psycho-oncology outpatient department did not have any psychiatric syndrome. Around 16.3% of patients could be managed without a prescription for any medications and almost half of the patients needed only one psychotropic medicine. Psychological interventions were used for 45.6% of patients.

Conclusion Integrated psycho-oncology services in a cancer hospital catering to patients with breast cancer help in psychiatric assessment, diagnosis, and addressing the mental health needs of patients. The treatment offered needs to be nuanced and individualized and may require a combination of psychotropic medications and psychological techniques.
The factors associated with teachers’ job satisfaction and their impacts on students’ achievement: a review (2010–2021)
Authors: Hoque Kazi Enamul , Wang Xingsu , Qi Yang , Norzan Normarini
Published: April 2023

The success of any educational organization depends heavily on the effectiveness of its teachers, who are tasked with transferring knowledge, supervising students, and enhancing the standard of instruction. Teachers’ job satisfaction has a significant impact on the lessons they teach since they are directly involved in transferring knowledge to students. In order to determine the effect of teachers’ job satisfaction (TJS) on students’ accomplishments, the researchers sought to analyze the empirical studies conducted over the previous 12 years (SA). To determine the characteristics that link to instructors’ job satisfaction and their effect on students’ achievement, thirty-two empirical studies were examined. The analysis of world-wide empirical research findings shows four types of results: (i) In some countries, teachers’ job satisfaction is low, but students’ achievement is high (Shanghai, China, South Korea, Japan, Singapore) (ii) In some countries, teacher job satisfaction is high, but student achievement is low (Mexico, Malaysia, Chile, Italy). (iii) In some countries, teachers’ job satisfaction is high, and so is student achievement (Finland, Alberta, Canada, Australia). (iv) In some countries, teacher job satisfaction is low, which has a negative impact on student achievement (Bulgaria, Brazil, Russia). In sum, irrespective of countries, highly satisfied teachers give their best to their students’ success, not only by imparting knowledge but also by giving extra attention to ensure the better achievement of each student. The review of this study makes it even more worthwhile to reflect on the need to avoid stereotypical considerations and assessments of any objective presentation of the phenomenon and to reflect more deeply on the need to assess the validity of the relationship study.