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The defects have a remarkable influence on the electronic structures and the electric transport behaviors of the matter, providing the additional means to engineering their physical properties. In this work, a comprehensive study on the effect of Br‐vacancies on the electronic structures and transport behaviors in the high‐order topological insulator Bi4Br4 is performed by the combined techniques of the scanning tunneling microscopy (STM), angle‐resolved photoemission spectroscopy (ARPES), and physical properties measurement system along with the first‐principle calculations. The STM results show the defects on the cleaved surface of a single crystal and reveal that the defects are correlated to the Br‐vacancies with the support of the simulated STM images. The role of the Br‐vacancies in the modulation of the band structures has been identified by ARPES spectra and the calculated energy‐momentum dispersion. The relationship between the Br‐vacancies and the semiconducting‐like transport behaviors at low temperature has been established, implying a Mott variable ranging hopping conduction in Bi4Br4. The work not only resolves the unclear transport behaviors in this matter, but also paves a way to modulate the electric conduction path by the defects engineering. [ABSTRACT FROM AUTHOR]

The defects have a remarkable influence on the electronic structures and the electric transport behaviors of the matter, providing the additional means to engineering their physical properties. In this work, a comprehensive study on the effect of Br‐vacancies on the electronic structures and transport behaviors in the high‐order topological insulator Bi4Br4 is performed by the combined techniques of the scanning tunneling microscopy (STM), angle‐resolved photoemission spectroscopy (ARPES), and physical properties measurement system along with the first‐principle calculations. The STM results show the defects on the cleaved surface of a single crystal and reveal that the defects are correlated to the Br‐vacancies with the support of the simulated STM images. The role of the Br‐vacancies in the modulation of the band structures has been identified by ARPES spectra and the calculated energy‐momentum dispersion. The relationship between the Br‐vacancies and the semiconducting‐like transport behaviors at low temperature has been established, implying a Mott variable ranging hopping conduction in Bi4Br4. The work not only resolves the unclear transport behaviors in this matter, but also paves a way to modulate the electric conduction path by the defects engineering. [ABSTRACT FROM AUTHOR]

Relevance. The need to shift the focus to renewable energy sources and increase the usage of the electric vehicles. This gives us the access to the areas where conventional combustion engines are forbidden. The goal is not only reducing CO2 emissions, but also it is necessary to increase the autonomy of vehicles and their independence from infrastructure. Aim. To calculate the power generated by photovoltaic panels based on the insolation of the area of Tomsk, Russia, to define the efficiency of electrically driven research boat powered by the solar energy. Subject. An electrically driven motorboat, built by a student team according to the "Project Activity" training program at Moscow Polytechnical University. Methodology. Calculation using empirically and experimental data and the data from the open source. Results. We have defined the method for calculating the running time of the electrically driven solar powered boat. We obtained as well an approximate amount of the electrical power generated by the solar panels for the area of Tomsk in summer. As a result, we calculated the boat running time for a summer day at a speed of 7 km/h. This method can be used for the calculation of the energy balance of infrastructure-independent vessels, as well as floating autonomous platforms for research, mining, and transportation at restricted areas.

In the modern world, the problem of the ecological state of our planet is acute. The environmental situation depends on many factors, these include both natural phenomena and human actions. One solution to this problem is to replace traditional internal combustion engines with more environmentally friendly electric vehicles.THE PURPOSE. The objective of this study is to analyze the internal structure of an electric vehicle, based on the training stand “Electric Vehicle Motor”, as well as to study the functions of this device, located at the Kazan State Energy University.METHODS. The authors of the article processed and analyzed the capabilities of modern laboratory equipment that simulates the operation of a particular component of an electric vehicle.RESULTS. The technology of the laboratory bench operating the electric vehicle, together with the DVT Customer software, allows for full control of the electric motor, as well as monitoring and changing a large number of parameters that affect the operation of the entire device as a whole.CONCLUSION. Since electric vehicles are gaining more and more popularity every year, the demand for people capable of diagnosing, repairing, and even improving existing ones and developing new components and assemblies in the field of electric vehicles is growing significantly. Using the “Electric Vehicle Motor” stand for teaching technical subjects and conducting research work can serve as a good basis for the formation of a general knowledge base about electric transport, its structure, the operating principle of all the main elements, monitoring and diagnostics of an electric vehicle.

RELEVANCE. The challenges of creating modern permanent magnet synchronous motors require solving technical problems in conjunction with economic realities. Due to the use of permanent magnets in the construction of synchronous motors, their cost limits their industrial application. Therefore, there is an urgent issue of optimizing the design of synchronous motors, which can be solved by changing the topology.TARGET. The goal is to create more economical permanent magnet synchronous motors (PMSMs) in low-power electric vehicles. It is planned to implement a new method for constructing PMSM. This solution will reduce weight and size parameters and increase specific power, which are important indicators for electric transport.METHODS. To modernize modern synchronous motors, a complex topological optimization method based on a genetic algorithm is proposed.RESULTS. A computer model was obtained in the form of calculation of electromagnetic fields in the stator and rotor of a synchronous motor with permanent magnets.CONCLUSION. Modeling the parameters of synchronous motors with permanent magnets has a low degree of development in the domestic mechanical engineering due to the lack of developed infrastructure in the field of low-power electric transport; the creation of domestic developments in this area is of a strategic nature.

The work considers one of the possible approaches to the creation of a capacitive type wireless charger, which allows for non-contact charging of batteries of small-sized vehicles: electric carts, electric scooters, electric scooters. The basis of the development of such a device is the operation of the hybrid DC-DC converter circuit, which operates at a high frequency (550 kHz), transfers energy to the charging circuit using two capacitive elements and allows receiving a constant regulated voltage on the load, which can be either lower or and more input DC voltage. A prototype of such a device has been developed and the results of its experimental research are given, which confirm the possibility of using this scheme for wireless charging of the battery. A Simulink computer model of such a device has been developed, which takes into account the real values of all parameters of the developed prototype and uses the basic model of a lithium-ion battery. According to the results of the calculations, it was determined that for the developed device of the capacitive type, and the largest losses occur in the inductor coils, the value of efficiency, which characterizes the efficiency of the process of transferring electrical energy from the primary power source to the battery, at the initial stage of its charging (when the parameter of the state of the battery SOC =50%) is 80%. References 10, figures 5. [ABSTRACT FROM AUTHOR]

Using the solid-state reactions method Na0.55(Co,M)O2 (M = Cr, Ni, Zn, W, and Bi) ceramics were prepared and their crystal structure, microstructure, electrophysical, thermophysical, and thermoelectric properties were studied. Doping of Na0.55CoO2 by transition or heavy metal oxides led to the increase in the grain size of ceramics, a decrease in electrical resistivity and thermal diffusivity values, and a sharp increase in the Seebeck coefficient, which resulted in essential enhancement of their thermoelectric properties. The largest power factor (1.04 mW/(m·K2) at 1073 K) and figure of merit (0.702 at 1073 K) among the studied samples possessed the Na0.55Co0.9Bi0.1O2 compound, which also demonstrated the highest values of the Seebeck coefficient (666 μV/K at 1073 K). The obtained results show that the doping of layered sodium cobaltite by different metal oxides allows for improving its stability, microstructure, and functional properties, which proves the effectiveness of the doping strategy for developing new thermoelectric oxides with enhanced thermoelectric performance. [ABSTRACT FROM AUTHOR]

In this article, the authors consider issues related to the efficiency of the use of electric transport in cities. Currently, environmentally friendly modes of transport, including means of individual mobility, are becoming increasingly relevant. To determine the prospects for the development of electric transport in cities, it is necessary to evaluate the performance indicators of its work. Based on the experience of using electric transport, it can be concluded that the development of this type of transport in the cities of our country is a promising direction. The purpose: the purpose of this study is the efficiency of the use of electric transport in cities. Within the framework of achieving the set goal, it is necessary to solve the following tasks: analysis of the characteristics and effectiveness of various types of electric transport; analysis of the experience of using electric transport in urban conditions. Method or methodology of the work: when conducting research, the authors used such research methods as analysis, practical modeling. Results: to date, the following results have been achieved: comparative costs of electric transport and other types of urban transport have been analyzed. The international experience of using electric transport is analyzed. The technical characteristics of vehicles, the consumption of electrical energy, the possibility of charging and operation in urban conditions are considered. Scope of application of the results: research activity on the development of new approaches in the field of organization of transportation on vehicles with alternative energy sources.

The article examines the specifics of the formation of scenarios for the development of the electric power industry in Russia (including district heating) as an integral part of the scenarios for the decarbonization of the national economy. Technological opportunities for reducing carbon emissions through the development of low-carbon and carbon-free technologies for the production of electricity and heat are considered. The potential impact of the cross-sectoral factor—large-scale electrification, replacement of fossil fuels with electricity—on the volume of electricity consumption is estimated. Using the EPOS energy planning optimization model, various forecasts of the structure of electricity and district heat production up to 2050 are obtained, taking into account options for carbon emission quotas and the development of electric transport. Increases in total capital investments and total energy supply costs are determined, which are necessary for a more intensive growth of generating capacities and a low-carbon transformation of their technological structure while reducing carbon emissions in the electric power industry, taking into account increased demand. [ABSTRACT FROM AUTHOR]

RELEVANCE. The lack of easily accessible charging stations is becoming a negative factor in the growth of the adoption of electric vehicles. Consequently, the planning and placement of charging stations is gaining momentum among researchers around the world. One of the promising solutions is the use of mobile charging stations, which can solve the problem of the stationarity of existing solutions. TARGET. To confirm the relevance of the study and determine the current technical level in the field of charging stations for electric vehicles (for comparison with the technology being developed on the basis of Kazan State Power Engineering University and the Zarnitsa production association), an analysis of patent information was made. METHODS. The authors of the article defined terms and keywords for analysis, collected data on specialized sites and carried out a detailed analysis of a number of patents from different countries, research organizations. RESULTS. The maximum level of development is at the level of TRL 3-5, but the analysis of patent activity indicates an increase in the number of intellectual property objects, which may indicate a future sharp increase in the level of TRL, and the need for their own developments ready for mass production, for which the authors developed a flowchart of the developed mobile electric vehicle charging installation, indicating the features: the ability to supply power to the network, wireless charging for electric vehicles, the availability of all major types of charging for electric vehicles, the possibility of integrating renewable energy sources, dynamic energy distribution. CONCLUSION. The technical level of developments in the field of mobile charging stations for electric vehicles does not allow talking about ready-made solutions that can be used to develop the charging infrastructure of the Russian Federation, and the development of a domestic solution in the form of mass production is necessary.

In the evolving landscape of electromobility, the logistics domain is undergoing significant transformations, reflecting broader changes in both the transport and energy sectors. This study aims to present an exploration of the scientific literature indexed in Scopus dedicated to electromobility logistics and the business ecosystem. The methods used in this article include a classical literature review and a systematic literature review, combined with bibliometric analysis in VOSviewer software (version 1.6.19). These methods allowed for the analysis of keywords and research motifs related directly to the development of electromobility from a business ecosystem perspective. Results of this study indicate that while technological innovations play a significant role, the success of electromobility is also highly dependent on its efficient and collaborative business ecosystem of entities involved in transportation and energy sectors. This ecosystem, defined by mutual value creation and strategic collaboration along with infrastructure and logistics, has the potential to drive economic growth and create new green jobs in the energy and transport sectors. In conclusion, the study underscores the importance of a sustainable and balanced approach, emphasizing both technological advancements and the significance of a robust business ecosystem for the future of the electromobility business ecosystem. [ABSTRACT FROM AUTHOR]

We study the effect of a local potential shift induced by a side electrode on the edge modes at the boundary between gapped and ungapped bilayer graphene. A potential shift close to the gapped-ungapped boundary causes the emergence of unprotected edge modes, propagating in both directions along the boundary. These counterpropagating edge modes allow edge backscattering, as opposed to the case of valley-momentum-locked edge modes. We then calculate the conductance of a bilayer graphene wire in presence of finger-gate electrodes, finding strong asymmetries with energy inversion and deviations from conductance quantization that can be understood with the gate-induced unprotected edge modes. [ABSTRACT FROM AUTHOR]

Monocycles have become a means of micromobility and an environmentally friendly alternative in urban environments, but their design and operation challenge traditional traffic rules intended for conventional vehicles. There is a need for clear and adapted traffic regulations in the modern landscape of transport systems that consider the unique characteristics of unicycles. The research aims to explore the specifics and justify the importance of establishing road safety rules specifically for monowheels based on a comparative analysis of the laws and best practices of the United States, the European Union and Ukraine. The necessity of creating comprehensive guidelines that would consider the presence of monowheels on roads, bicycle paths and sidewalks is discussed in the article. The absence of special rules creating safety problems for both monowheel users and pedestrians is noted. The problems are identified, and potential solutions are proposed. The crucial role of adapted traffic rules in promoting safe and efficient coexistence in the modern transport ecosystem is emphasised. The author analyses the regulatory documents of the USA, the European Union and Ukraine regarding the legality of using electric unicycles and the responsibility of their owners and compares them. The problems encountered by monowheel users and other road users are identified and their comprehensive solution is proposed. The author highlights the areas which can be influenced to improve road safety for monowheel users in Ukraine and also suggests specific options for possibly borrowing of practical experience of the USA and the European Union countries regarding the traffic rules for monowheel users. The practical significance of the article lies in promoting the safe and informed use of electric unicycles by streamlining the legislative framework, establishing clear rules of operation, and conducting fiscal discussions and educational activities. The study can be a valuable asset for owners and users of electric unicycles, as well as for government agencies and legislators [ABSTRACT FROM AUTHOR]

Currently, the estimated range of an electric vehicle is a variable value. The assessment of this power reserve is possible by various methods, and the results of the assessment by these methods will be quite different. Thus, building a model based on these cycles is an extremely important task for manufacturers of electric vehicles. In this paper, a simulation model was developed to determine the range of an electric vehicle by cycles of movement. A mathematical model was created to study the power reserve of an electric vehicle, taking into account four driving cycles, in which the lengths of cycles and the forces acting on the electric vehicle are determined; the calculation of the forces of resistance to movement was carried out taking into account the efficiency of the electric motor; thus, the energy consumption of an electric vehicle is determined. The modeling of the study of motion cycles on the presented model was carried out. The mathematical evaluation of battery life was based on simulation results. Simulation modeling of an electric vehicle in the MATLAB Simulink software environment was performed. An assessment of the power reserve of the developed electric vehicle was completed. The power reserve was estimated using the four most common driving cycles—NEDC, WLTC, JC08, US06. Studies have shown that the highest speed of the presented US06 cycle provides the shortest range of an electric vehicle. The JC08 and NEDC cycles have similar developed speeds in urban conditions, while in NEDC there is a phase of out-of-town traffic; therefore, due to the higher speed, the electric vehicle covers a greater distance in equal time compared to JC08. At the same time, the NEDC cycle is the least dynamic and the acceleration values do not exceed 1 m/s2. Low dynamics allow for a longer range of an electric vehicle; however, the actual urban operation of an electric vehicle requires more dynamics. The cycles of movement presented in the article provide a sufficient variety and variability of the load of an electric vehicle and its battery over a wide range, which made it possible to conduct effective studies of the energy consumed, taking into account the recovery of electricity to the battery in a wide range of loads. It was determined that frequent braking, taking into account operation including in urban traffic, provides a significant return of electricity to the battery. [ABSTRACT FROM AUTHOR]

The article is devoted to the design of an asynchronous traction motor intended for work as part of an electric drive of vehicles: electric vehicles, electric buses, trams, trolley buses. The object of the study is a medium-sized bus. The required traction characteristics of the electric motor are constructed, the nominal and limiting characteristics of the increased torque. The dynamic characteristics have been built for a bus with a mechanical transmission and a diesel engine, as well as for a bus with an electric motor. A method is proposed for designing an electric motor based on mathematical modelling of its operation in the software complexes ANSYS RMxprt and INFOLYTICA MAGNET. According to this technique, the main parameters of the electric motor are determined. The results of modelling are given, graphs of the criteria dependence on the electric motor parameters. Experimental studies of the electric motor have been carried out. The results of mathematical modelling are compared with experimental ones. It was found that the discrepancy between the results of experimental and theoretical studies is no more than 5 %.

The penetration of electric vehicles is becoming more and more widespread and recently electric buses and trains are fetching the attention of researchers and developers. In this review, we examine the charging systems applied to the fast charging of electric vehicles and buses as well as the charging strategies, mainly applied to electric buses. We also briefly delve into power topologies for a more electrified railway system where we discuss their different supply systems as well as their motor drive systems. Problems and charge challenges for electric buses and trains are discussed too. [ABSTRACT FROM AUTHOR]

THE PURPOSE. Charging infrastructure is one of the factors influencing the transition to electric vehicles, as the electric vehicles in operation are characterized by a small range and a long battery charge period. Today, the development of the charging infrastructure depends only on the networks of stationary charging stations, which also have disadvantages (high cost, lack of mobility, etc.). Therefore, the purpose of this work is to study the design features of mobile electric vehicle charge units (MCSEU) for the development of draft design documentation for the creation of a new MCSEU project. This issue includes the study of the world market of manufacturers of modern mobile chargers, the study of technical and operational features that are today presented to modern energy storage and storage systems.MATERIALS. The authors of the article processed and analyzed data on the current state of the charging infrastructure in Russia and the world, based on materials from Russian and foreign authors, as well as information on the development strategy of the electric transport industry in Russia and the world, in particular, data from Madison Gas and Electric.RESULTS. The obtained analytical results are one of the aspects that will be taken into account when developing mobile charging devices for electric vehicles. This mobile charger technology significantly expands the possibilities of using electric vehicles, in particular electric vehicles, and also solves various problems of the fuel and energy complex associated with autonomous power sources and distributed generation systems.CONCLUSION. The charging infrastructure is one of the factors influencing the transition to electric vehicles, as the electric vehicles in operation are characterized by a small range and a long period of charging the traction battery. However, this process will be long and in the near future networks of charging stations will be created, including mobile charging units for electric vehicles.

The growth of the vehicle assets and bus services in Ukrainian cities increases the level of environmental pollution. During the environmental crisis, electric transport (e-transport) is becoming a matter for scientific inquiry, a subject of discussion in politics and among public figures. In the program for developing the municipal services of Ukraine, priorities are given to the development of the infrastructure of ecological transport: trolleybuses, electric buses, electric cars. The increased attention to e-transport on the part of the scientific community, politicians, and the public actualizes the study of its history, development, features of operation, etc. The historiographic analysis carried out by the authors allows us to say about insufficient coverage by Ukrainian researchers of a number of aspects and periods in the history of e-transport. A small number of special works on the history of the operation of foreign-made trolleybuses in Ukrainian cities in the first half of the 20th century and an analysis of their technical characteristics determine the relevance and scientific novelty of this study. When writing the work, Ukrainian and foreign scientific reference publications, monographs, papers, mainly from foreign electronic resources, have been used. The authors have used both general scientific (analysis, synthesis, deduction, induction) and historical research methods, in particular, problem-chronological, comparative-historical, retrospective methods, etc. The aim of the study is to highlight little-known facts of the history of production and operation of MAN trolleybuses in Ukrainian cities, as well as to introduce their technical characteristics into scientific circulation. The etymology of the model names of German trolleybuses, which usually consisted of the names of the manufacturers of chassis, body, and electrical equipment, has been clarified. The types, specific design solutions of the first MAN trolleybus generation and the prerequisites for their appearance in Chernivtsi have been determined. Particular attention has been paid to trolleybuses that were in operation in Germany and other Western European countries from the first half of the 1930s to the early 1950s. In the mid-1930s, the MAN plant in Nuremberg began production of trolleybuses; its models had the most modern constructive solutions at that time, a characteristic design and a state-of-the-art heating system. Depending on the length, German manufacturers divided the trolleybus models into four types. As a result of problems with the operation of the bus fleet in Chernivtsi, the city authorities have decided to build a trolleybus line in the city; four trolleybuses manufactured by the MAN plant were purchased. The paper traces the stages of operation of the MAN trolleybuses in Chernivtsi, where they worked during 1939–1944 and after the end of the Second World War, they were transferred to Kyiv. After two years of operation in the Ukrainian capital, the trolleybuses entered the routes in Dnipropetrovsk during 1947–1951. The technical characteristics of the first MAN trolleybus generation, which were operated in Ukrainian cities, have been presented and analyzed. It was determined that in all the main indicators and operational parameters, they were as close as possible to similar models of German trolleybuses. The proposed methodology and the structure of the study can later be used to write papers on the history of science and technology, in particular, of an e-transport.

Purpose: To highlight the key trends in the transportation industry and the role of emerging technologies and digital transformation in acceleration of value creation. The conceptual framework suggests how such transformation could be implemented. Design/methodology/approach: Research in a focus group was carried out where selected digital transformation frameworks were reviewed, and one was selected as the most applicable to the transportation industry. The selected framework was adopted for the transportation industry. Findings: 1. Value creation should be positioned as the key objective of transformation. 2. Digital transformation is not so much about technology as it is about people. 3. The staged approach towards transformation allows it to be paced with account being taken of the maturity of technology as well as the maturity of competencies across the organization. For a successful digital transformation, the organization invests in development of digital capabilities. Moving towards digital means a mindset shift, cultural change and adoption of new methods of working. Research limitations/implications: Transportation companies are at the early stage of transformation at such a scale. The case studies on successful transformations are limited. Therefore, experience is gathered mainly by the test and learn process. It is recommended that findings are validated with a􀁢wider group of experts when transformation matures. Comparing the same framework usage in other industries can also offer additional learnings to be considered by change leaders. Originality/value: Transportation industry is in a process of transformation towards connected, electric and autonomous solutions, accelerated during the COVID-19 pandemic. The presented framework, adopted for the transportation industry, offers a practical tool for executives and change leaders to lead the transformation.

Purpose. The work is aimed to present the results of a comprehensive study of the bench testing procedure of high-current sliding contact of electric transport, which together provide a basis for proposals, recommendations for improving the standard method of these tests. Methodology. The research is based on two classical methods of scientific research. The first one is the observation and processing of the results of a real experiment in the laboratory; the second is the development of mathematical model for determining the temperature effect in the area of sliding contact on the wear of the contact wire, with subsequent determination of the resource of this sliding contact. Findings. The result of these studies is a list of recommendations on the procedure and content of the program-methodology of bench tests of inserts of current collectors of electric transports. The obtained scientifically substantiated results will allow to assert that their introduction will reduce time, energy and other expenses for performing obligatory bench tests of new samples of current collector inserts. Originality. By means of non-destructive temperature control at the point of current collection of high-current sliding contact, taking into account the temperature limit value during current collection process, for the first time the values of the heating time constant of the «insert fragment – contact wire ring» were obtained for different insert materials. This makes it possible to predict the final result of bench tests as successful or unsuccessful already at the initial testing stage (the first 10 thousand disk passes). Based on statistical processing of experimental data, the dependences of the contact wire wear on the number of test bench passes were obtained, which creates conditions for forecasting the value of contact wire wear during bench tests relative to the reference sample. Practical value. It is experimentally proved that the dependence of the contact wire wear on the number of passes of the test bench disk is linear, which allows accelerated resource testing of high-current sliding contact elements while maintaining the adequacy of the results. In general, the comprehensive application of the received recommendations creates conditions for saving time, energy and other costs when conducting bench tests of sliding contacts of electric transport.

The correlation between dielectric relaxation and conduction mechanisms in the Ba 0.9 La 0.1 Fe 12 O 19 ceramic hexaferrite, at temperatures below 100 K was investigated. The sample was prepared using the conventional solid-state reaction method. X-ray diffraction analysis indicated that the sample is composed of a hexagonal BaFe 12 O 19 phase (lattice parameters a = 5.8778(6) Å and c = 23.170(3) Å) and a small proportion of hematite (α-Fe 2 O 3). The average grain size is 1.48 ± 0.4 μm, with irregular hexagonal and agglomerated grains. The magnetic hysteresis curve shows characteristics typical of ferro and ferrimagnetic materials, with an effective magnetic anisotropy coefficient of 0.960×106 emu/cm3 and an anisotropy field of 1.587×104 Oe. A dielectric relaxation process is observed between 50 and 100 K, with an activation energy of 60.4 ± 0.4 meV and a characteristic relaxation time of 2.09 ×10−10 s, mainly attributed to the electrical behavior of the grains. Two conduction mechanisms were identified: small polaron tunneling (high temperatures and low frequencies) and correlated barrier hopping of electrons (low temperatures and high frequencies). The activation energy for free polaron formation, according to the Komine-Iguchi hopping polarization model, was 7.12 ± 0.02 meV. In the dielectric modulus relaxation process between 30 and 54 K, the activation energy was 40.8 ± 0.9 meV, with a characteristic relaxation time of 2.41×10−10 s. The small polaron conductivity in the grain region was 67.52 meV and 54.0 meV in the grain boundary region. The results highlight that the polarization and conduction mechanisms in this ceramic at low temperatures are dominated by small polaron hopping and tunneling, and emphasize the influence of La3+ doping on the structural, magnetic, and electrical properties of barium hexaferrite. • Dielectric relaxation and activation energy: The complex permittivity behavior showed dielectric relaxation between 50 and 100 K. The activation energy for free polaron formation was determined using the Komine-Iguchi hopping polarization model, resulting in 7.12 meV. • Second dielectric relaxation process: A second dielectric relaxation process, linked to small polaron hopping, was observed in the 30–54 K range in the dielectric modulus. • Conduction mechanisms: Conductivity analysis revealed two distinct conduction mechanisms: Correlated Barrier Hopping (CBH) and Nonoverlapping Small Polaron Tunneling (NSTP). The contribution of the NSTP mechanism increased mobility and conductivity. [ABSTRACT FROM AUTHOR]

Electric road systems (ERS) constitute a promising technology for mobile charging and relieving mandatory stops to recharge electric vehicles. However, the ERS operation is constrained by the limitations of the Power Distribution Network (PDN) that provides electricity. This study proposes a integrated optimization of a coupled ERS-PDN system (including traffic assignment and power flow modeling), in the presence of self-interested electric vehicle drivers, diverse flexibility resources and uncertainty of energy supplies (e.g. uncertainty from renewable energy). The security of the PDN while supporting ERS can be ensured by using active and flexible energy storage and flexible power loads. A semi-dynamic model is adopted for the traffic assignment. A stochastic bi-level optimization based on Stackelberg game under uncertainty is proposed to model the joint optimization problem to minimize the general cost of coupled ERS-PDN system and maximize the profit of the energy flexibility provider. Then, the Karush Kuhn Tucker conditions are deployed to convert the bi-level model to the equivalent single level model. The results demonstrate the effectiveness and benefits of the proposed framework using numerical experiments. The results show that the proposed optimization can reduce the burden of an ERS on the underlying PDN in improving the violated voltage by 3.66%, demonstrating the effect of joint consideration of diverse sources of flexibility. • A semi-dynamic approach to address the dynamic nature of coupled APDN and wireless ERS. • A framework to develop flexibility in the coupled coordination of APDN and ERS. • Joint minimization of the total cost of APDN and the imposed travel time to ERS. [ABSTRACT FROM AUTHOR]

The paper presents a theoretical background to determine the inactive power consumption features, i.e. the reactive power according to S. Fryze approach of the electric transport systems. Traction electric circuits of transport facilities of electric locomotives, feeder traction substations and city trams used in Ukraine demonstrate three features of the reactive power. According to the classical method, the inequality between the active and total power indicates the presence of the reactive power. The second feature is the time variation of an instantaneous impedance or instantaneous conductivity. The third is the inequality between the instantaneous reactive power to zero and the nature of its sign throughout the time of the electric power system consumption. The reactive power consumption gives rise to considerable additional power losses in the electric traction transport systems. [ABSTRACT FROM AUTHOR]

The article discusses the main directions of the development of converter equipment in Russia and worldwide. Major global trends in the development of converter equipment are assessed through the scope of priorities for technological development of the Russia's energy sector. The main areas of application are analysed and the local inverter market is investigated, specifically in electric transport, solar and wind power generation, distributed smart power systems, including energy storage systems. Inverters are decomposed in minute detail, specifically in terms of the critical technologies and an electronic component base that need to be developed in Russia. Creation of advanced modules for inverters in Russia is exemplified with an ongoing project of developing and establishing a production of specialized IGBT modules in MIDA body. Certain suggestions as to development of production of converter equipment in Russia through the cooperation of the state and the private sector are made. [ABSTRACT FROM AUTHOR]

The coupling between electrons and phonons is ubiquitous in condensed matter physics. In recent years, with the rise of two dimensional (2D) materials, electron–phonon interaction exhibits unique characteristics compared with their three‐dimensional counterparts. In this paper, research progress of electron–phonon interaction in 2D materials is briefly reviewed, mainly focus on thermoelectric device, conventional superconductor, field effect transistor, and photoelectric device. Firstly, electron–phonon interaction on thermoelectric application of 2D materials is concluded according to recent reports, and strategies to increase figure of merit are discussed. Next, strong electron–phonon coupling strength is essential for increasing transition temperature of superconductors. Conversely, electron–phonon interaction inhibits the carrier mobility for transport process. By summarizing research works in the past years, its role on the performance of 2D materials‐based field effect transistors is fully evaluated. Furthermore, the influences of electron–phonon interaction on light–matter interaction in 2D materials are briefly overviewed. Finally, some outlooks in the field are prospected. In a word, understanding electron–phonon interaction in 2D materials establishes strategically important directions for manipulating physical properties and optimizing device design. [ABSTRACT FROM AUTHOR]

A simulation model of an electric-traction network is proposed taking into account the nonlinear properties of traction substations and traction converters of electric rolling stock, the effect of voltage on the current collector on its traction characteristics, the exchange of energy between sections of the traction network through the substations' buses, and the traffic-modeling practice. The model checking in terms of distribution of feeder currents of traction substations recorded by a special recording device is performed. Using the proposed model, the effect of the open-circuit voltage of traction substations on the level of energy losses in the tram and subway traction networks is studied. The substation feeders current distribution is obtained, and the factors affecting the efficiency of regenerative braking in urban electric transport are researched. The model can be used to determine the traffic capacity and calculate short-circuit currents, as well as for energy-saving measures by reducing energy losses in the traction network, transferring and storing electric braking energy, and other purposes. [ABSTRACT FROM AUTHOR]

This study is dedicated to solve manoeuvres making task while working on the station with no marshalling hump. It is part of the project aimed at the development of intelligent safety and optimal control systems of autonomous electric vehicles and transport in general. The main manoeuvres safety depends on the lack of items and other objects on the rails as well as on the position of turnouts. In most cases rails, occupied with other wagons, as well as the wrong position of turnouts are marked with prohibiting red or blue signals of the traffic light. The authors propose an algorithm for the traffic light recognition by using a convolutional neural network (CNN) and traffic light indicator recognition. However, the situation when the locomotive needs to drive on the rails occupied with other wagons, for example, during the manoeuvres on the railway station can also appear. For this purpose, the authors have developed a CNN algorithm for the wagon recognition on the rails.

Electric transport is rapidly gaining popularity across the world. It is an example of technological advancement that has multiple consequences for regional economies, both in terms of the adaptation of production, transport and energy systems and their spatial optimization. The experience of leading economic regions, including countries of the Baltic Sea region, shows that electric transport can potentially substitute traditional transport technologies. Based on an authentic model of system dynamics, the authors propose a new approach to simulation modelling of the dissemination of electric vehicles in a given region. The proposed model allows the authors to take into account the key systemic feedback loops between the pool of electric vehicles and the charging infrastructure. In the absence of data required for the econometric methods of demand forecasting, the proposed model can be used for the identification of policies stimulating the consumer demand for electric vehicles in regions and facilitating the development of the electric transport infrastructure. The proposed model has been tested using real and simulated data for the Kaliningrad region, which due to its specific geographical location, is a convenient test-bed for developing simulation models of a regional scale. The proposed simulation model was built via the AnyLogic software. The authors explored the capacity of the model, its assumptions, further development and application. The proposed approach to demand forecasting can be further applied for building hybrid models that include elements of agent modelling and spatial optimization.

This paper is part of a research program funded by the Provence-Alpes-Côte d’Azur (PACA) region that focuses on mobility practices for the 2030 and 2050 horizons. Transport is a sector in constant evolution. Recently, we observed the rise of the new individual electric vehicles (NIEV) in our cities. These vehicles are part of today’s mobility, and certainly tomorrow’s, due to the use of electric energy. This makes them attractive in the context of reducing carbon emissions in urban centers. In the spring of 2020, France experienced a lockdown related to the Covid-19 health crisis. The unlock, considered "risky", obliged politicians to urgently set up temporary cycling paths that are also used by NIEV. These vehicles appear to be the most advantageous in terms of social distancing, unlike public transport. This sudden increase in temporary infrastructures, some of which will become permanent, suggests that it will reinforce the growth of NIEV in urban areas.In order to better understand the growth of NIEV, an online survey was shared during April and May 2020. The objective of this survey is to better understand the users and uses of these vehicles. The survey is also intended for non-users who are in direct contact with NIEV users. The survey questions the opinion on the preservation of the environment, the necessary arrangements concerning these vehicles, etc. At the end of May 2020, the survey gets 250 responses, including 120 NIEV users. In addition, interviews were conducted to obtain qualitative data.The results of the survey identified several environmental and urban planning issues. For example, 68.3% of users are convinced that NIEV are environmentally friendly. In addition, 84.2% of users consider them to be practical and useful in urban areas. The open-ended questions and interviews shed light on ideas for improvements to these new transports. Indeed, many users and non-users report difficulties for NIEV to circulate in urban areas. These vehicles have not yet found a suitable place to circulate and are often circulating on sidewalks, cycling paths, or even on the road.

The two-dimensional (2D) structure often leads to unusual phenomena for the impact of confined mean free path of carrier scattering. As a quasi-2D layered material, AgCrSe2 has a liquid-like phonon behavior for its unstable Ag atoms at service temperature, leading to the promising candidate for thermoelectricity and fast ionic conductor. However, the inferior electronic performance constrains its application prospects as a functional semiconductor, which provides broad opportunity to tune its electric behaviors by defect chemistry. In this work, we revealed abundant electric transport behaviors of AgCrSe2 with different types of intrinsic defects. For example, the AgCrSe2 changes from Anderson insulator to metal when Se defects become prevailing and the magnetoresistance alters its sign depending on the relative ratio of Ag and Cr defects. Our results reported here can give salutary boosting on regulating the electric properties of ternary transition metal selenide by defect chemistry. [ABSTRACT FROM AUTHOR]

The energy transition based on variable renewable energy sources raises concerns on satisfying the electricity demand at all hours of a year, which is amplified by the ongoing energy system electrification. Balancing variable electricity supply and inelastic demand requires additional sources of flexibility in the system: flexible electricity generation, energy storage, grids, flexible demand, and overall sector coupling. Electrification of transport increases the electricity demand; however, it offers the opportunity to use additional low-cost flexibility from electric vehicles batteries. The LUT Energy System Transition Model was modified to model the smart charging and vehicle-to-grid functionality of electric vehicles in integrated energy systems. The results show that, in countries with a large fleet of electric vehicles, smart charging and vehicle-to-grid allow for a substantial reduction of energy storage requirements, reducing the electricity and heat storage capacity by 35% and 25%, respectively and leading to 4% lower system cost. Flexible operation of electrolysers required for e-fuels synthesis have a similar effect and, in combination with smart charging and vehicle-to-grid, can lead to 8% lower system cost. The impact of vehicle-to-grid naturally depends on assigned operational cost; however, it contributes to system cost reduction even at high costs of 50 or 100 €/MWh. • Co-use of EV batteries reduces stationary battery storage capacity by 50 %. • If combined with flexible electrolysers stationary battery capacity reduces by 76 %. • Flexible electrolysers impact comparable to supplier-managed charging and V2G. • Additional flexibility options can lead to higher grids utilisation. • System cost reduces by 8 % if EV-related and electrolyser flexibilities are active. [ABSTRACT FROM AUTHOR]

The 5d oxide Sr 2 IrO 4 with a layered perovskite structure has been investigated due to its peculiar J eff = 1/2 insulating ground state. In this research, we investigate the evolution of magnetic and electric transport properties of Er-doped polycrystalline perovskite iridates Sr 2– x Er x IrO 4 (0 ≤ x ≤ 0.06). Er3+ is magnetic and can thus provide magnetic interactions with Ir. Also, Er3+ doping introduces a carrier-doping effect. We find that substituting Sr2+ with Er3+ still preserves the I 4 1 / acd crystal structure, while it causes the rotation of IrO 6 octahedra φ to decrease. In this case, the Ir–O1–Ir bond angle increases and the tetragonal distortion c / a decreases. The magnetic properties present a suppressed transition temperature, a decreased Curie–Weiss temperature, and an increased effective magnetic moment. The electrical resistivity of the doped samples decreases with doping, which originates from the crystal distortion and electron doping. Theoretical calculations represent an increase in band filling and an improvement in the conduction property with doping. [ABSTRACT FROM AUTHOR]

Electric transport properties and magnetoresistance (MR) of the array of metallic single-wall carbon nanotube bundles irradiated by the electron flux with the energy close to 1 MeV or Co60 gamma quanta have been investigated within the temperature range T = 1.8…200 K and in the magnetic fields up to 5 T. The power-law behavior of the conduction vs temperature was observed within the range 50 to 200 K, which is typical for conduction of quasi-one-dimensional systems in the model of the electron gas as the Luttinger liquid. The change in power exponent  with the radiation dose and its deviation as compared to α for the non-irradiated samples is related with changing the number of conduction channels in the bundles as a consequence of the radiation defects appearance. At the temperatures below 50 K, the Mott three-dimensional hopping conduction is realized. Using the measured dependence of conduction on the temperature and electric field, the density of electron states in the vicinity of the Fermi level, which participate in the hopping charge transport, and the localization length of charge carriers in these states have been determined. These parameters determining the hopping mechanism of the charge transport are noted to depend on the radiation dose. The magnetoresistance in the Mott-type hopping conduction region was negative in the whole range of magnetic fields, while at the large fields an upturn to the positive change was observed. The mechanisms both of the negative and positive MR components are discussed.

The article presents the advantages of the available types of elevated electric transport. The conditions have been indicated for ensuring reliable, economical and environmentally current of collection by electric transport. The results of experimental studies are published of negative factors of current collecting in real conditions of operation of elevated electric transport. The methods are considered that increase the environmental safety of current-collecting. The description is given of the best designs current of collectors with excellent environmental specifications.

The article presents estimates regarding the scale of changes arising from the mass introduction of electric vehicles. The relevance of this paper is determined by the increasing demands for the environmental cleanliness of transport energy sources. It is obvious that in the future alternative fuel vehicles will crowd out oil fuel transport. I propose an original approach to the economic evaluation of the alternative resources’ use in transport taking into account regional conditions and initial data’s uncertainty. It allows comparing new technologies in transport and choosing the most efficien t option s for power supply of passengers and freight vehicles in the country’s different regions. The main feature of the proposed model is the combination of optimization and simulation methods based on the Monte Carlo technique. The study identifies the trends in the dynamics of motorization and the structure of energy resources in the transport sector and assesses the possible consequences of the electric vehicles’ introduction in Russia. It also includes the results of experimental calculations using various combinations of expected conditions and forecasting prices in accordance with the demand for motor fuel in major macro regions of Russia. The article has demonstrated that the economic efficiency of the use of alternative fuels and energy in transport will depend on regional characteristics, in particular, on the dynamics of changes in prices for energy resources. The proposed methodological approach and the results obtained can be useful in studying the problems of the power industry development.

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The authors of the study work out to determinate of the mathematical model of supercapacitors as an object of an electric traction system capable of providing non-encumbering of obtaining research results and correct reproduction of energy exchange processes in conditions of repeated-short-term modes of traction load operation. In paper, authors make a comparative assessment of six models for the possibility of their integration into the model of electric traction systems with on-board placement of the energy storage. [ABSTRACT FROM AUTHOR]

Introduction. This article deals with the problem of moisture condensation inside the cabin of the technological electric transport vehicle. The hypothesis of using the forced air ventilation in the cabin is substantiated, by which such problem could be solved.Materials and methods. The article describes the application of the ANSYS Fluent Software Package to assess the effect of the location and shape of the ducts on the ventilation process inside the cabin. Accordingly, the key stages of air flow modeling in this program are considered.Results. The main content of the research is to analyze the modeling airflow process in the cabins with a different configuration of inlet and outlet nozzles. Therefore, basing on the analysis of the obtained airflow velocity contours, the conclusion is made about the rational arrangement of the inlet and outlet channels.Discussion and conclusions. The conclusion is made about the necessity of the further research that would refer to creating a three-dimensional model of the cabin. The results of the research as well as resolutions are taken into account.

Purpose. The work is aimed to study the change in parameters of traction electric motors of trolleybuses during operation and improvement of the technical state control system, using modern diagnostic methods. Methodology. Solution of the scientific problem is based on the control of technical state and change in the parameters of traction electric motors in the process of operation. For analysis of operational factors, we used the method of mathematical statistics and probability theory. Mathematical modelling and design of experiment, multifactor regression analysis provides an assessment of the reliability of the electric traction motor elements. Physical and statistical methods provide for research and detection of patterns of influence of the factors that accelerate the wear of parts. This allows us to generate models of system reliability that take into account the influence of operational factors on the reliability. Findings. As a result of the studies we obtained quantitative characteristics of the reliability of commutator and established that the failures of traction motors make up 20% of all failures of electrical equipment. We analysed the operation conditions of traction electric motors and determined the failure distribution law N{mx,sx}, which allows assessing the progression between gradual failures. We obtained a mathematical model characterizing the object operation. A generalized equation of the failure rate of elements for traction electric motor (TEM) was found. We improved the estimation methods of reliability of TEM element base that makes it possible to determine the ETM lifetime taking into account the features of each trolleybus. We established the failure rate of commutators using physical and statistical methods. Originality. For the first time, the choice of physico-statistical methods of simulation and reliability calculation was substantiated. We determined the regularities of change in parameters of the trolleybus traction electric motor elements, which makes it possible to control the processes of their wear in the operation conditions. We developed a mathematical model for estimating the traction electric motor reliability, based on a system analysis of the probabilities of failures of subsystems to be diagnosed. Practical value. Based on the results of the study, we developed practical recommendations for rational choice of diagnostic parameters of traction motors. Their implementation at the enterprises of electric transport will increase reliability of electric motors in general up to 10%. It is proposed to use the results of the work in the educational process and in the research work of students at the Department of Electric Transport of the O.M. Beketov National University of Urban Economy in Kharkiv. The developed methodology for determination of parameters of traction electric motors when operating trolleybuses allows assessing the reliability of any type of trolleybus traction motor.

The conducted research shows that the EU-27 and the UK have a varied approach to electric scooters when it comes to law: some see them as means of micro-transportation or personal transport, others define them exclusively in their legislation (in a direct manner). In some countries electric scooters are not defined in legislation but other rules apply (e.g. rules on bicycles). Electric scooters' users are qualified either as pedestrians using scooters, drivers, or cyclists. The limit of 20 - 25 km/h of speed is a general benchmark. The rules on the access to pavement, pedestrian zones, and pedestrian crossings vary among the Member States (some allow it, providing speed limits; others offer only the possibility of accessing bike paths or public roads). National legislation also provides some other requirements, such as age limits for electric scooter users when riding on a road or wearing protective equipment (e.g. helmet or safety vest). The research also proves that the majority of Member States do not provide any special rules on driving licences or insurance (generally not required when using electric scooters). Finally, the article addresses a seemingly basic legal European framework on electric scooters and a possible harmonization by adopting the Micromobility Directive. [ABSTRACT FROM AUTHOR]

The behavioral features of the spectra of impedance components and electric module for copper-doped polycrystalline zinc-sulfide layers are investigated. The dispersion of the frequency dependences of the electrical parameters corresponding to the distribution of the relaxation time is established. An equivalent sample circuit that includes a constant phase element and describes electric transport features in the polycrystalline system under study is used to interpret the experimental data. [ABSTRACT FROM AUTHOR]

We investigate the complex optimization problem that arises in the planning of the transition process from traditional public transport to electric transport. We define the assumptions, input and output parameters of the problem, as well as its mathematical model and a randomized algorithm for solving it. We also give an extensive bibliography of publications on the problem at hand. [ABSTRACT FROM AUTHOR]

The article provides an overview and comparative analysis of various types of batteries, including the most modern type—lithium-ion batteries. Currently, lithium-ion batteries (LIB) are widely used in electrical complexes and systems, including as a traction battery for electric vehicles. Increasing the service life of the storage devices used today is an important scientific and technical problem due to their rapid wear and tear and high cost. This article discusses the main approaches and methods for researching the LIB resource. First of all, a detailed analysis of the causes of degradation was carried out and the processes occurring in lithium-ion batteries during charging, discharging, resting and difficult operating conditions were established. Then, the main factors influencing the service life are determined: charging and discharging currents, self-discharge current, temperature, number of cycles, discharge depth, operating range of charge level, etc. when simulating a real motion process. The work considers the battery management systems (BMS) that take into account and compensate for the influence of the factors considered. In the conclusion, the positive and negative characteristics of the presented methods of scientific research of the residual life of LIB are given and recommendations are given for the choice of practical solutions to engineers and designers of batteries. The work also analyzed various operating cycles of electric transport, including heavy forced modes, extreme operating modes (when the amount of discharge and discharge of batteries is greater than the nominal value) and their effect on the degradation of lithium-ion batteries.

Highly ordered nanostructure arrays have attracted wide attention due to their wide range of applicability, particularly in fabricating devices containing scalable and controllable junctions. In this work, highly ordered carbon nanotube (CNT) arrays grown directly on Si substrates were fabricated, and their electronic transport properties as a function of wall thickness were explored. The CNTs were synthesized by chemical vapor deposition inside porous alumina membranes, previously fabricated on n-type Si substrates. The morphology of the CNTs, controlled by the synthesis parameters, was characterized by electron microscopies and Raman spectroscopy, revealing that CNTs exhibit low crystallinity (LC). A study of conductance as a function of temperature indicated that the dominant electric transport mechanism is the 3D variable range hopping. The electrical transport explored by I–V curves was approached by an equivalent circuit based on a Schottky diode and resistances related to the morphology of the nanotubes. These junction arrays can be applied in several fields, particularly in this work we explored their performance in gas sensing mode and found a fast and reliable resistive response at room temperature in devices containing LC-CNTs with wall thickness between 0.4 nm and 1.1 nm.

The Ecuador’s expansion plans for the power sector promote the exploitation of hydro power potential, natural gas and a small share of alternative renewable energies. In 2019, electricity generation reached 76.3% from hydroelectric power, 21.9% from thermal plants and 1.8% from other renewable resources. Although the power energy mix is mainly based on renewable technologies, the total energy demand is still dependent on fossil fuels, which is the case of the transport sector that alone accounted for 50% of the total primary energy consumed in the country. This paper analyzes the pathway to develop a clean and diversified electricity mix, covering the demand of three specific development levels of electric transportation. The linear optimization model (urbs) and the Ecuador Land Use and Energy Netwrok Analysis (ELENA) are used to optimize the expansion of the power system in the period from 2020 to 2050. Results show that reaching an electricity mix 100% based on renewable energies is possible and still cover a highly electrified transport that includes 47.8% of land passenger, and 5.9% of land freight transport. Therefore, the electrification of this sector is a viable alternative for the country to rely on its own energy resources, while reinforcing its future climate change mitigation commitments.