bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation of oxygen transport by incorporating Sb2Te3 layer in HfO2-based memristor
Authors: Zhu Yun-Lai , Li Li-Heng , Qiao Chong , Zeng Yun-Tao , Yuan Jun-Hui , Cheng Xiao-Min , Miao Xiang-Shui
Published: November 2021

The oxygen transport plays an important role on the uniformity of the transition metal oxides (TMOS) memristors. Here, the effect of incorporating Sb2Te3 layer into TiN/HfO2/Pt memristor on oxygen transport has been systematically explored. The experimental results reveal that the memristor with Sb2Te3 incorporation at TiN/HfO2 interface has improved switching uniformity and memory window. Further theoretical calculations demonstrate that Sb2Te3 is a proper oxygen reservoir as oxygen possesses very low formation energy and migration barrier in Sb2Te3 with many vacancies. During the operation process, the Sb2Te3 will gain more oxygen from the HfO2 layer than TiN once the applied voltage reaches up to forming voltage, producing more oxygen vacancies (VOs) in the HfO2 layer, compared with the device without the Sb2Te3 layer. Thus, the VOs conductive filaments (CF) in the HfO2 layer will be thick, resulting in a decrease in the randomness of CF's formation/rupture and, in turn, improving the device uniformity. Our findings provide an in-depth understanding of the oxygen reservoir in TMOS memristors, which is of great significance for the design and development of memristors.
Analytical second derivatives of the free energy in solution by the reference interaction site model self-consistent field explicitly including constrained spatial electron density distribution
Authors: Yokogawa Daisuke , Suda Kayo
Published: November 2021

The application of analytical derivative methods to solution systems is important because several chemical reactions occur in solution. The reference interaction site model (RISM) is one of the solvation theories used to study solution systems and has shown good performance, especially in the polar solvent systems. Although the analytical first derivative based on the RISM coupled with quantum methods (RISM-SCF) has already been derived, the analytical second derivative has not been proposed yet. Therefore, in this study, the analytical second derivative was derived using RISM-SCF explicitly including constrained spatial electron density distribution (RISM-SCF-cSED). The performance of this method was validated with the Hessian calculations of formaldehyde and para-nitroaniline in solution, and the results demonstrated that the method accurately calculated frequency values at a small computational cost.
A generalized hybrid scheme for multireference methods
Authors: Waigum A. , Black J. A. , Köhn A.
Published: November 2021

A generalization of the hybrid scheme for multireference methods as recently put forward by Saitow and Yanai [J. Chem. Phys. 152, 114 111 (2020)] is presented. The hybrid methods are constructed by defining internal and external excitation spaces and evaluating these two subsets of excitations at different levels of theory. New hybrids that use the mix of internally contracted multireference coupled-cluster, unshifted multireference coupled electron pair, and multireference perturbation methods are derived and benchmarked. A new separation of the excitation space, which combines all singles and doubles excitations to the virtual orbitals into the external space, is also presented and tested. In general, the hybrid methods improve upon their non-hybrid parent method and offer a good compromise between computational complexity and numerical accuracy.
Dealing with trouble in conversation in English-speaking cultures
Authors: Haselow Alexander
Published: November 2021

This paper deals with the features of the system of other-initiated repair in different varieties of English, and thus in different cultural settings in which English is spoken. Corpus-based data are used to investigate whether and how repair practices, which are essential to the human communication system, vary across English-speaking cultures. The data show that while, on the whole, repair practices are very similar across different varieties, there are differences with respect to the frequency of the different formats deployed for removing trouble and differences as regards the preferred strategies for restoring and maintaining mutual understanding.
Profiling learners through pragmatically and error annotated corpora
Authors: Weisser Martin
Published: November 2021

This proof-of-concept study presents a novel way of analysing learner language based on 20 randomly selected interviews from the Chinese part of the Louvain International Database of Spoken English Interlanguage (LINDSEI) (Gilquin et al., 2010), annotated both pragmatically and using a newly devised error analysis scheme. Annotation and initial analyses were primarily conducted in the Dialogue Annotation and Research Tool (DART) (Weisser, 2016b), and the relevant features extracted and normed by the number of functional (speech act) units to obtain meaningful comparable results across speakers. The results indicate that the majority of errors affect the coherence of the learners’ narrative and that the communicative strategies used by the learners exhibit a high number of discourse markers or response-signals used (em)phatically, apparently only serving as ‘planning facilitators’, rather than genuine structural or interactional devices.
Exploring the impact of data-driven learning in extensive reading
Authors: Hadley Gregory , Hadley Hiromi
Published: November 2021

While much of the research into the efficacy of data-driven learning (DDL) has focused on productive skills such as writing, less attention has been on how DDL affects receptive skills, such as reading. This chapter presents a four-year mixed-methods study, which investigates the impact of DDL on the extensive reading (ER) proficiency of second language learners in a Japanese national university. Conducted in three stages and under a wide range of class conditions, this study concludes that explicit forms of DDL are most successful with small groups and one-to-one instruction, where personal feedback and less pressure are key. Implicit forms of DDL tend to work best with larger class sizes, where it results in faster reading speeds and in greater amounts of material read.
Scoledit
Authors: Wolfarth Claire , Ponton Claude , Brissaud Catherine
Published: November 2021

The purpose of Scoledit is to build a computer-aided longitudinal corpus of texts written by pupils between 6 and 11 years as well as associated automatic processing tools. This project seeks to produce linguistic descriptions of pupils’ writings and to facilitate the teaching of spelling and writing. Currently, an increasing number of projects aim to create large primary school corpora of French (Elalouf, 2005; Garcia-Debanc & Bonnemaison, 2014; David & Doquet, 2016). However, these corpora are neither longitudinal nor associated with natural language processing (NLP) tools (Wolfarth, 2017). This chapter discusses some of the automated tools for linguistic analyses developed and the advantages of the Scoledit project in the context of language teaching
The Camel Humps prosodic pattern
Authors: Matalon Nadav
Published: November 2021

This chapter presents an analysis of a common
prosodic pattern in spoken Hebrew. The pattern is characterized by a
repetition of high rise-fall pitch movements, which visualize as
successive “humps” in the pitch curve.1 Based on analysis of naturally occurring conversations,
I show that speakers use this pattern to construct open lists of
reinforcements for a counter-stance they take. In some cases, the use
of the pattern is itself the act of taking a counter-stance, that is,
in such cases the disaffiliation between the stance-takers is only
prosodically cued. Such cases demonstrate that prosodic list patterns
are used not only for the task of enumerating items under one
category, but also as a resource for complex interactional
activities.

The structure of the chapter is as follows. In Section 1, I introduce the
premises underlying this study and describe the data. Section 2 includes a formal
analysis of the pattern, followed by a functional analysis in Section 3. Conclusions are
drawn in Section 4.
Online text mapping
Authors: Sammarco Carmela
Published: November 2021

This is a corpus driven study on verbless
constructions (Cxs[ØVP]) in spoken Italian and French that
have a textual naming function, namely verbless constructions that
speakers use to name what they are going to talk about. This paper
suggests that these constructions are tools that speakers use as
structure’s mapping in the discourse to orient the listener and
themselves and that build meta-discursive and meta-textual ad
hoc categories. These structures are frequent in very
high informative texts (i.e. meetings and conferences) and their
occurrence correlates with the information’s density in texts.
Et cetera, eccetera, etc. The development of a
general extender from Latin to Italian
Authors: Fiorentini Ilaria , Magni Elisabetta
Published: November 2021

This paper discusses the range of functions of
et cetera in Latin, as well as the
multifunctionality and evolution of eccetera in
Italian. Both forms pertain to the category of general extenders, i.e.
markers whose main function is to ‘extend’ otherwise grammatically
complete utterances. We will propose a qualitative analysis based on
data from Latin, Old Italian, and contemporary written and spoken
Italian. In particular, we will discuss the semantic-pragmatic
expansion of et cetera and eccetera,
highlighting how both expressions tend to develop intersubjective and
procedural meanings in addition to their original functions. Moreover,
since the original components of eccetera are by now
blurred in contemporary Italian, we will show how recent developments
allow its use in disjunctive contexts.
Morphopragmatics of rhyming and imitative co-compounds in
Russian
Authors: Alexandrova Anna , Benigni Valentina
Published: November 2021

Coordinative compounding is a phenomenon at the
crossroads between word-formation, syntax and discourse, adopted for
encoding non-lexicalized concepts in a wide range of languages. We
propose a morphopragmatic account of two specific coordinative
compounding strategies in Russian, namely, rhyming and imitative
co-compounds. They exhibit non-compositional semantics, inasmuch as
they perform a generalizing/categorizing function, which, in turn, is
tightly intertwined with a strong pragmatic evaluative component,
involving irony and downgrading of the referent. Furthermore,
different means of categorization tend to cluster in discourse, thus
resulting in pervasive overcoding of the respective ad
hoc concepts. Since categorization is a result of an
online process of meaning negotiation between speakers, we have to do
with low-frequency single instances of a frequent phenomenon.
Characterization of irradiation effect on 5251 Al-alloy using rietveld x-ray diffraction analysis
Authors: Sayed Zoda , Abdel-Rahman M , Abdel-Rahman M A , Badawi Emad A
Published: November 2021

This work aims to study irradiation doses (0, 100, 200, 400, 600 and 1000 kGy of Co60
γ-source doses) effect on 5251 Al-alloy samples using XRD analysis. The main structures of the x-ray diffraction patterns are the same, a considerable difference in the peak intensities is observed due to the grain growth associated with increasing of irradiation doses. The intensity ratio of higher reflections declares that nearly 600 kGy irradiation dose is the preferred orientation or threshold point. Microstructure characterization has been studied using x-ray Diffraction Line Profile (XDLP) analysis. Minimum crystallite size of about 0.106 μm is measured for non-irradiated sample, maximum value is observed at 600 kGy. Micro-strain decreases exponentially with increasing irradiation dose, in addition the cell parameter seems to be constant. The dislocation and defect densities reveal the same behavior as the micro-strain. The defect and dislocation density decrease exponentially with increasing of irradiation doses with maximum values of about 1.10 × 1019 cm−3 and 3.15 × 1010 cm−2 respectively obtained for non-irradiation. The variation of the stored dislocation energy due to irradiation doses reveal maximum stored dislocation energy of about 334.95 kJ m−3 for non-irradiated sample, then it is approximately kept constant with increasing of irradiation dose up to 1000 kGy.
Terahertz graphene modulator based on hybrid plasmonic waveguide
Authors: Huang Jinwen , Song Zhengyong
Published: November 2021

As a key component of on-chip interconnection, optical modulator with large modulation depth and tiny footprint has always been studied. Profiting by high carrier mobility and flexible adjustability of graphene, numerous graphene modulators at optical communication band are proposed to overcome inherent flaws of traditional semiconductor waveguide modulators. Here, a terahertz waveguide modulator combing noble metal and graphene is presented. When Fermi level changes from 0 eV to 1 eV, intensity distribution of electric field becomes dispersed. Interaction area of graphene and wave increases, which results in larger propagation loss. On the premise of the existence of the allowed mode, the size of metal and the thickness of dielectric should be small. Besides, modulation capability of this device can also be improved by multilayer graphene with relaxation time of 0.1 ps. After optimizing structure parameters, the designed graphene waveguide modulator obtains modulation depth of 6.1 dB μm−1 at the frequency of 5 THz, and keeps effective mode area below 10−5. With the increase of frequency, modulation depth decreases. Modulation depth of 1.5 dB μm−1 is achieved at 10 THz, but the corresponding effective mode area remains in an ideal range. Because the allowed mode is confined in a tiny room, cross-sectional area of device is less than 4 μm2.
Charged BTZ-type solutions in Eddington-inspired Born-Infeld gravity
Authors: Guerrero Merce , Mora-Pérez Gerardo , Olmo Gonzalo J. , Orazi Emanuele , Rubiera-Garcia Diego
Published: November 2021

We construct an axially symmetric solution of Eddington-inspired Born-Infeld gravity coupled to an electromagnetic field in 2+1 dimensions including a (negative) cosmological constant term. This is achieved by using a recently developed mapping procedure that allows to generate solutions in certain families of metric-affine gravity theories starting from a known seed solution of General Relativity, which in the present case corresponds to the electrically charged Banados-Teitelboim-Zanelli (BTZ) solution. We discuss the main features of the new configurations, including the modifications to the ergospheres and horizons, the emergence of wormhole structures, and the consequences for the regularity (or not) of these space-times via geodesic completeness.
Exciton luminescence and many-body effect of monolayer WS2 at room temperature
Authors: Wu Jian-Min , Li Li-Hui , Zheng Wei-Hao , Zheng Bi-Yuan , Xu Zhe-Yuan , Zhang Xue-Hong , Zhu Chen-Guang , Wu Kun , Zhang Chi , Jiang Ying , Zhu Xiao-Li , Zhuang Xiu-Juan
Published: November 2021

Monolayer transition metal dichalcogenides favor the formation of a variety of excitonic quasiparticles, and can serve as an ideal material for exploring room-temperature many-body effects in two-dimensional systems. Here, using mechanically exfoliated monolayer WS2 and photoluminescence (PL) spectroscopy, exciton emission peaks are confirmed through temperature-dependent and electric-field-tuned PL spectroscopy. The dependence of exciton concentration on the excitation power density at room temperature is quantitatively analyzed. Exciton concentrations covering four orders of magnitude are divided into three stages. Within the low carrier concentration stage, the system is dominated by excitons, with a small fraction of trions and localized excitons. At the high carrier concentration stage, the localized exciton emission from defects coincides with the emission peak position of trions, resulting in broad spectral characteristics at room temperature.
Improving sound diffusion in a reverberation tank using a randomly fluctuating surface
Authors: Li Qi , Xie Dingding , Tang Rui , Shang Dajing , Lv Zhichao
Published: November 2021

Underwater reverberation environments that satisfy the conditions of uniformity and isotropy of the diffuse field can be used to measure the acoustic characteristics of underwater targets. This study combines two practical indicators — the standard deviation of the absolute sound pressure field (to indicate uniformity) and the analysis of the wavenumber spectrum in the spherical harmonics domain (to indicate isotropy) — for an accurate evaluation of the diffusion of the sound field in a reverberation tank. A method is proposed that can improve the narrow-band diffusion of the sound field by employing a randomly fluctuating surface. An acoustic experiment was performed in a reverberation water tank (1.2 m × 1 m × 0.8 m), where a randomly fluctuating surface was generated by making waves. The experimental results show that as the wave motion contributes effectively to the random reflection of sound rays in all directions, the uniformity and isotropy are improved significantly when the surface is fluctuating randomly. This work helps to ensure accurate measurements of the characteristics of underwater targets in reverberation tanks.
Incommensurate–commensurate magnetic phase transition in double tungstate Li2Co(WO4)2
Authors: Chen Xiyu , Ding Ning , Liu Meifeng , Zou Tao , Garlea V. Ovidiu , Gong Jingwen , Liu Fei , Xie Yunlong , Yang Lun , Zheng Shuhan , Wang Xiuzhang , Dong Shuai , Charlton T. , Liu Jun-Ming
Published: November 2021

Magnetic susceptibility, specific heat, and neutron powder diffraction measurements have been performed on polycrystalline Li2Co(WO4)2 samples. Under zero magnetic field, two successive magnetic transitions at T
N1 ∼ 9.4 K and T
N2 ∼ 7.4 K are observed. The magnetic ordering temperatures gradually decrease as the magnetic field increases. Neutron diffraction reveals that Li2Co(WO4)2 enters an incommensurate magnetic state with a temperature dependent
k
between T
N1 and T
N2. The magnetic propagation vector locks-in to a commensurate value
k
= (1/2, 1/4, 1/4) below T
N2. The antiferromagnetic structure is refined at 1.7 K with Co2+ magnetic moment 2.8(1) μ
B, consistent with our first-principles calculations.
Operational features of battery-powered electric vehicles in Russia and methods of assessing a state of health of traction batteries
Authors: Biksaleev R , Klimov A , Malikov R , Karpukhin K
Published: November 2021

Electric vehicle manufacturers pay particular attention to climatic conditions in the Russian Federation, seeing that chemical reaction rates usually decrease when the environment temperature drops. The analysis of ambient temperature data in the region where electric vehicles will most likely be used aims to select extreme temperatures for calculating powers of a thermostat control system for traction batteries. An electric vehicle simulation model to calculate the power of the thermostat control system for traction batteries is described. An empirical model to assess a state of health of traction batteries is selected. This simulation model adequately reflects thermal processes in a traction battery and can be used for further research.
Charging balance management for automotive battery in low-voltage power network under low temperature conditions and at deep discharge of the automotive battery in the car
Authors: Debelov V V , Malyshev A N , Chechranova O A , Dzhodzhua O A , Kozlovskiy V N
Published: November 2021

The paper presents the results of theoretical analysis and mathematical modeling and implementation of algorithms for controlling the charging balance of battery in a low-voltage power network at low temperatures and at deep discharge of the battery as part of an intelligent vehicle control system with a combined power unit. The target of the research is to develop methods to prevent the critical discharge of the battery, methods of charging the battery and methods for control of the current state of the automotive battery. Experiments were performed, experimental data and graphs were obtained. The results of the research allow performing adjustment of the rechargeable battery charge balance management model and contribute to improving the energy balance of the grid, increasing the efficiency and service life of batteries.
Noise of small-scale contra rotating rotors
Authors: Boychuk I P , Grinek A V
Published: November 2021

This article presents the results of an experimental study of the noise characteristics of small-scale coaxial counter-rotating rotors. The tests were carried out in an anechoic soundproof chamber for F7/A7 counter-rotating rotors with 11 and 9 blades on the front and rear rotors, respectively. The intensity of noise emission by rotors was compared with the constancy of the thrust of the power units. Acoustic studies have shown the presence of tonal and broadband noise components at low rotation speeds. In addition to the usual noise components, tonal components were also observed for the rotor blade running combinations. The observed noise levels at these frequencies are equal, and in some directions are significantly higher than the noise levels at the frequencies of the blades of the first and second rows. In experiments, it was found that, while maintaining the equality of the rods, with an increase in the diameter, the noise levels at the rotors decrease due to a decrease in peripheral speeds. A decrease in the noise levels of rotors with an increase in the number of blades was established due to a decrease in aerodynamic loads on the blades and peripheral speeds. An important parameter here is the filling factor of the space swept by the blades. With an increase in this coefficient, the rotation noise decreases, but the vortex noise increases significantly.
Analysis of causes of failure of the electric centrifugal pump elements by the methods of automated diagnostics
Authors: Suleimanov Rustem I , Ya Khabibullin Marat , Suleimanov Renard I
Published: November 2021

The article discusses the issues of assessing the technical condition of electric centrifugal pumps (ECP) by the methods of automated diagnostics. The factors influencing the ECP and causes of failures of the electric centrifugal pump (ECP) and the submersible electric motor (SEM) are analyzed. The results of ECP failure identifiaton using the measuring systems are presented. Recommendations on the operation of electric centrifugal pumps are provided.
Optimizing the power quality by reducing harmonic distortion in the power supply network for isolated territories
Authors: Suslov K , Solonina N , Solonina Z , Akhmetshin A
Published: November 2021

New technologies of electric power generation, such as generation based on renewable energy sources, distributed generation, make extensive use of modern power electronics. All these non-linear elements generate harmonic components in the supply voltage. This leads to a deterioration in the quality of the supplied energy. In this regard, improving the quality of supplied energy is an urgent task. The article proposes a method of continuous distributed monitoring of the quality of electrical energy in the isolated power systems. This method is based on the use of the PMU infrastructure to continuously obtain information on instantaneous values of currents and voltages. It is proposed to use a smart meter proposed earlier by the authors as a primary measuring instrument for monitoring the level and direction of harmonics in various sections of the power system. This procedure is carried out in the current time mode, and thus there is a continuous adjustment of the power supply system to a mode close to optimal in terms of the content of harmonic components (harmonics) in the supply voltage at the selected points of connection.
Experimental studies of single rotors noise of small scale
Authors: Boychuk IP , Grinek AV
Published: November 2021

The work experimentally investigated the characteristics of the noise of large-scale isolated rotors on small-scale models. The experimental rotor model was based on the F7 / A7 design developed by General Electric. The small diameter rotors were 3D printed and powered by brushless DC motors. The studies were implemented at a speed of up to 8500 rpm. Far-field acoustic measurements were performed in a noise-damped anechoic chamber. The noise characteristics of the brushless motors used in the experiments were investigated separately. For brushless motors, the main component is mechanical noise at the speeds of the motor shaft and its harmonics. For a uniaxial electric motor, the mechanical noise at the shaft speed increases with an increase in the rotational speed, while the noise at its higher harmonics decreases. The study of the coaxial electric motor showed an increase in mechanical noise at the higher harmonics of rotation. In experiments with insulated rotors, the tonal and broadband noise content was recorded. The study showed that with an increase in the rotational speed of a single rotor, the noise level rises from 65 to 80 dB. In this case, the maximum sound pressure shifts towards higher frequencies.
Evaluating significance of relation between a material electroerosion resistance and electroerosive machining pulse energy
Authors: Boyko A F , Blinova T A , Syusyuka E N
Published: November 2021

The paper presents results of research into dependence of electroerosion resistance on the energy of discharge impulses during electroerosive machining. A new criterion is proposed for evaluation of electroerosion resistance of materials. A direct dependence has been determined experimentally between the electroerosion resistance and the energy of discharge impulses. This relation is weak and close to linear. A mathematical model has been developed for this dependence. Scope of application is defined for the research results.
Mathematical model of the evolution of operating parametersof dielectrics in the marine power supply system when forcing certain factors
Authors: Litskevich O N , Litskevich A P , Litskevich S A , Pisarenko G P
Published: November 2021

The paper addresses the issue of development of a mathematical model for the evolution of operating parameters of dielectrics in the marine power supply system when forcing certain factors. The paper addresses a comprehensive problem in comparison with the classical problem of the wear theory. With regard to the given details, factors that cause a decrease in the operating time were introduced to determine the operating time before electrical wear of the power supply unit. The study employs methods of the fuzzy (uncertain) set theory. The uncertainty of quantities in the fuzzy set theory is set by the membership function, which determines the degree of its fuzziness. In accordance with fuzzy set methods, a membership function is constructed to estimate fuzziness of the function of a shrinking time resource of operating time before wear. In Mathcad, the authors have developed a computational module for estimating the fuzzy time (due to inaccuracy of the initial data) subtracted from the total operating time before electrical wear of the berthing power supply unit. To improve the reliability of power supply to seaports and reduce accidents, new technical and organizational measures are being developed. Therefore, the task is formulated to ensure serviceability of the power supply system with due regard to its interactions with various subsystems.
Implementation algorithm and mathematical model of contactless power transmission for powering an electric vehicle
Authors: Bryanskikh T B , Malozyomov B V
Published: November 2021

The work is devoted to methods for increasing the energy efficiency of photovoltaic modules. Various algorithms for determining the maximum power points and their application to obtain the maximum possible efficiency when using solar panels are considered. The principles of the operation of algorithms are described, their advantages and disadvantages are indicated. Their comparison was carried out according to the main significant parameters. The most suitable algorithm for application at a weather station has been selected.
Gas fuel combustion and related problems
Authors: Bashkatov VA , Khudyakov SA , Ignatenko AV
Published: November 2021

Combustion, as it is well known, is based on chemical reactions. If we look at a clear scientific definition of the term “combustion”, then combustion will be a process of rapid high-temperature oxidation, combining physical and chemical phenomena. Combustion consists of a large number of elementary redox processes leading to the redistribution of valence electrons between atoms of interacting substances.Modern theories of combustion relate flame spreading in gases to chemical chain reactions[1]. Nowadays, in a view of the wide spread of gas, understanding of a ship fuel and analysis of gas related problems of combustion are more and more critical. Gas itself is not able to ignite in a combustion chamber as a conventional fuel just because of compression and temperature rising. It requires a strong and efficient source of fire. The article is focused on analyzing igniting, flame spreading and detonation in a combustion chamber. The detonation condition was assessed in case of using gas as ships fuel.
Heat exchange processes in automotive internal combustion engines
Authors: Ushnitsky I N
Published: November 2021

Combustion chamber diameters, an advance angle of fuel injection, injection rate, minimum ratio of air excess, methods of forcing, and oil cooling affect the heat exchange processes of engines. The method of thermal calculation of the working cycle makes it possible to consider the change in the physical properties of the working fluid, the effect of heat transfer between the working fluid, and the environment during the implementation of the working cycle. The main parameters of the gas at characteristic points of the indicator diagram are determined as a result of performing a thermal calculation, which makes it possible to assess the cycle perfection degree. Some of the main parameters of the working fluid (pressure, temperature) and the nature of their change can serve as input data when calculating engine parts for strength. The amount of mechanical work obtained in the cycle and the value of gas volume at the expansion process end demonstrates not only efficiency, but also the dimensions and weight of the engine, namely, indicators that affect the overall layout of machines.
Calculation studies of the influence of exhaust gas recirculation on the characteristics of the natural gas-fueled diesel engine
Authors: Libkind I I , Gonturev A V
Published: November 2021

When converting diesel engines to run on natural gas on the gas-diesel cycle, additional problems arise associated with the high thermal stress of the exhaust valves and valve seats at high loads and engine speeds. There is also an increase in NOx emissions due to higher combustion temperatures of natural gas. One of the ways to improve the economic and environmental performance of engines operating on a gas-diesel cycle with a lean air-fuel mixture is to optimize the combustion of the air-fuel mixture by using an exhaust gas recirculation system (EGR). The principle of operation of this system is as follows: exhaust gas entering the intake manifold and further into the combustion chamber reduces the oxygen concentration in the air-fuel mixture, which leads to a dilution effect and, accordingly, to a decrease in combustion temperature and a decrease in NOx content. In order to study the influence of EGR on the dual-fuel gas and diesel engine parameters in the AVL Boost software package, a computer model of the existing 6ChN13/15 engine was developed. A low-pressure EGR system with an exhaust gas cooler was simulated on this engine. Values of NOx emissions, brake specific fuel consumption (BSFC) and brake efficiency have been obtained at different recirculation rate by calculation method. These values allow to estimate the feasibility of using a cooled EGR in a natural gas-fueled diesel engine.
Methodology of thermal loading estimation of the brake mechanism of a truck
Authors: Dygalo V G , Zhukov I S
Published: November 2021

The paper presents the results, conclusions of the assessment of friction pairs in the aspect of the phenomenon of fading. As you know, most of the kinetic energy of a car with ABS is extinguished due to the work of friction in the brake mechanism. Overheating the brake mechanism, namely its friction pairs, leads to the appearance of the phenomenon of critical fading, accompanied by a sharp decrease in the braking torque. When the metal friction elements of braking devices operate in a repeated-short-term mode, it is advisable to assess their operating parameters at a steady-state thermal regime, i.e. under the most severe temperature conditions. The proposed technique makes it possible to obtain a high convergence of the calculated values with the experimental data. Evaluation of thermally loaded using this method can be carried out at any stage of the design and does not require large computing power. Visualization of the results allows you to identify areas of increased heating to assess the need to change the design of the brake mechanism.
Parameters control for the damping element hydraulic buffer of the vehicle suspension
Authors: Cherepanov L A , Ivliev V A , Solomatin N S , Gordeev D A
Published: November 2021

The research investigates the impact coming from damping element hydraulic buffer of suspension on the vehicle smoothness. A change in the structural elements of hydraulic buffer for absorber rebound is considered in order to avoid hydraulic shock at the initial moment of its operation.
Stability of radio loops covering navigation systems and communication systems
Authors: Boran-Keshishyan AL , Alekseev AA , Popov VV
Published: November 2021

The development of the concept of E-navigation in modern shipping makes it necessary to create very reliable lines for the transmission of information packets and the interchange of data via radio networks to a huge number of consumers, practically all over the world. With such a scale, radio communication must be extremely reliable and stable, which is provided by the planetary system of satellite communication channels. The study proposes a method of signal loops of satellite communication systems for diagnosing the quality of the radio path, which will allow quickly localizing the external causes of the deterioration of the linear stability of communication in the absence of deep diagnostics during the daily operation of radio transmitting equipment. The organization of an external loop will make it possible to make a more accurate spatial adjustment of the antenna system to the zone of stable traffic with an increase in the steepness of the guidance system characteristics according to its own signal returned from the loop from the satellite. The external loop allows for more precise tuning of the antenna system of the stations, relative to the “steepness” of your own signal and to localize the external causes of signal deterioration by applying the method of signal loops.
Simulation of a vessel sensor network of ZigBee standard
Authors: Buzenkov I I , Redkin Iu V , Tyufanova A A , Khaleeva E P
Published: November 2021

The subject of the paper is a vessel sensor network designed to collect data from wireless sensors for various purposes. The peculiarity of this network application is the presence of a large number of premises, wireless communication between which is complicated. One of the possible approaches to solving this problem is to use coordinators connected by a switch into a local network, and a large number of routers that provide data relaying along the chain. Studies of the proposed vessel wireless network in the OMNeT ++ simulation modeling environment using Castalia framework are carried out in the paper. The process of modeling both the network itself and its individual components, and various modes of their operation is shown. The interaction of network nodes through intermediate routers is considered. Estimation of losses during packet delivery along a chain of routers, the time spent on processing packets in routers and delays in packet delivery to the network coordinator from the sending node is based on the compiled model. It is concluded that with the increasing complexity of the network structure (growth in the number of routers), there is a proportional rise of the packets delivery delay over the wireless network to the vessel local network. However, all transmitted packets are delivered to the addressee.
Simulation of ship handling in reverse
Authors: Lebedev O Y , Fil A V , Bondareva E V
Published: November 2021

One of the main problems of seamanship is steering the boat in reverse modes. This skill can be achieved using simulators or simulators that work based on a mathematical model. This model should adequately describe all ship maneuvers, including simulation in reverse modes. The article deals with the mathematical modeling of maneuvering from a ship in reverse. The authors performed model calculations, basic test maneuvers, such as “Circulation”, “Exit Circulation” and “Zigzag”. The analysis of trajectories testifies to the qualitative correspondence of the calculation results according to the mathematical model to the practice of navigation, and this model can be used for automatic control of the vessel, for assessing the movement of the vessel in reverse, and teaching navigation skills on simulators and simulators. The vessel when moving in reverse, at low speeds obeys the steering organ, but at speeds greater than the average stroke on the backward shift, it leaves the circulation very slowly and sometimes becomes uncontrollable. The withdrawal of a reverse circulation vessel is extremely difficult and requires additional skills and abilities from the navigator.
Analysis of methods to optimize control systems for power supply of marine vessels using fuzzy logic and fractal analysis
Authors: Khekert E V , Epikhin A I
Published: November 2021

The paper considers the features of promising methods to optimize the control systems for power supply of marine vessels using fuzzy logic and fractal analysis. In order to design an effective control contour for the power supply system (PSS), it is proposed to use synergistic mechantronic systems based on intelligent technologies with fundamentally new properties that allow for a more effective solution of control problems using fractal analysis of time series to increase the adequacy of forecasting through in-depth analysis of the causes of emergency situations. The synergistic effect SE of the control within such systems is a set of effects obtained as a result of their combination and synchronization in time and space. Practical aspects of fractal analysis are considered on the example of a two-cycle engine with supercharging and air cooling. In the study of fractal processes, a method is proposed for identifying and eliminating the short-term dependence of the value of the time series of the process S(t), which is characteristic of autoregressive processes, using regression with respect to S(t-1) and conducting the R/S analysis of the remainder X(t). Short-term dependence is eliminated provided that long-term dependence is maintained. Autoregressive AR(1) differences are analyzed at a certain time interval for various engine operating modes. The results of the R/S analysis of the engine operation and the determination of the Hurst exponent are used to increase the efficiency of forecasting and control of the PSS in the period of the detected chaotic behavior of the time series.
Error correction algorithms in on-board intelligent transport data transmission systems
Authors: Goloskokov K , Korotkov V , Nyrkov A , Knysh T
Published: November 2021

The paper describes the problems of assessing the quality of intelligent transport systems related to organizational and technical systems based on the system analysis of information technologies. It provides the theoretical basis for describing the quality assessment process of intelligent transport systems. The paper also justifies the method of quality assessment of complex systems, which include intelligent transport systems. It is shown that the modern system of intelligent systems should not only be effective, but also not violate the required operation mode. The characteristic evaluating the effect of the target functioning has the properties of measurability, completeness and reliability. The intelligent transport systems may include systems that in the process of control ensure the achievement of set targets with the necessary quality of target functioning in a counteracting environment. In order for the system to function correctly, it is necessary to agree on a set of targets and a set of conditions, i.e. to implement an integrated approach to the functioning of the system as a whole. With an integrated approach it is necessary to agree on all the targets set for the system, as well as all the conditions under which it will operate.
Research into the physical and chemical properties of fire-retardant materials of structural elements of trucks running on gas engine fuel with the aim of increasing their fire-retardant efficiency
Authors: Konoplev V , Zhukov A , Melnikov Z , Sarbaev V
Published: November 2021

The fire load is an integral part of the fire hazard definition. Reducing this load is one of directions to fight fires in transport. To study the physicochemical processes and thermal effects occurring as a result of thermal decomposition of wood fire-proofed by retardants like BAN, OK-GF, OK-DS (OK-GFM), SPAD-0 and their chemical compositions, we used the methods of differential thermal analysis, thermogravimetry, and derivative thermogravimetry. In addition, to study the intensity of physicochemical combustion processes, tests to control changes in woodwork masses and temperature at the top of pipe depending on the duration of combustion of the samples and the consumption of fire retardants were conducted. Fire retardant compositions like OK-GF, OK-DS, Pirilax biopyrene at the consumption of 0.1 kg / m2 ensure flame and combustion resistance of the wood. The analysis of the research results confirmed the possibility of assigning to wood structures of a lorry’s body of the group 1 of flame and combustion resistance. Using the above fire retardants and their compositions in the treatment of lodgment elements and runners significantly affects the possibility and duration of the combustion process of a lorry. This was tested by means of an artificial fire source method (without chemical treatment, the burning time does not exceed 50 minutes). This significantly improves post-collision safety of vehicles with an increased fire load in terms of fire resistance because of using the natural gas as a motor fuel.
Variation of the entropy analysis method in information flows of IBS in the concept of safe navigation development
Authors: Vasiutina AA , Popov VV , Kondratyev AI
Published: November 2021

The creation of a configuration by a bridge integrated system in the form of the control machine variation - artificial intelligence, becomes relevant in the concept of E-navigation development with the vector of the vessel’s directional control on the course, both in a small crew and unmanned way. It is possible to consider a large number of mathematical ideas about the basis for creating an intelligent control machine: an artificial neuron and fuzzy sets, Petri nets and Markov chains, Kolmogorov’s differential equations, which are difficult to configure and cumbersome to compute. Multiagent systems seem to be feasible. Integrated bridge systems with embedded supplementary reality assist management personnel in solving navigation issues. Saturation of the navigation control information complex of the bridge system with an increasing number of hardware and instrument units leads to a decrease in information entropy but does not bring to the full automatic control. In ergatic systems, object control is still reduced to declining the uncertainty to a minimum value by means of the operator’s control actions. The methodology for analyzing the entropy capacity of the system and elements of the augmented virtual assessment of the situation in the configuration of multifunctional machine units can be applied in the efficiency criteria development for vessel’s control systems with small crew or unmanned navigation in the concept of E-navigation.
Reconstruction of various navigational scenarios of the «Ever Given» ship, including grounding in the Suez Canal using the bridge simulator with up-to-date electronic navigation charts
Authors: Popov AN , Zelenkov GA , Papulov D S
Published: November 2021

The Suez Canal is the largest maritime shipping traffic thoroughfare in the world. The global cargo turnover accounts for 10-12%. Theaccident occurred on March 23, 2021 with the container ship “Ever Given”, blocking the Suez Canal. It fully paralyzed shipping traffic in the region and caused enormous damage to the economy. Reconstruction of various navigational scenarios of the containership, including grounding based on the bridge simulator, allowed examination of navigation and developing recommendations to prevent similar accidents in the future. Within the limits of the research, the authors used electronic navigation charts S-57 with up-to-date information on the accident time, a similar model of containership and hydro-meteorologic conditions in the bridge simulator’s session.An assessment of the risk of grounding a container ship has been carried out using the method of Bayesian trust networks.
Experimental studies of the thermal management system for an electric vehicle in the X-In-The-Loop environment
Authors: Kurmaev R H , Umnitsyn A A
Published: November 2021

This article presents the experience of conducting experimental studies of the thermal management system (TMS) intended for the traction electric drive of an electric vehicle, which has each of its wheels driven by an in-wheel motor, in the X-In-the-Loop environment. The paper describes the experimental bench of the thermal management system, which makes it possible to simulate the operating conditions of the high-voltage components of the traction drive of an electric vehicle from the point of view of thermal-hydraulic characteristics. A brief description of the mathematical model used in real-time calculations during both local and collaborative experimental studies is given. The process of collaborative testing of the TMS of high-voltage components of the traction drive of an electric vehicle, in the X-In-the-Loop environment, as well as the results, is demonstrated. A similar approach used in the development of TMS allows increasing the efficiency of the system developed, by optimizing the control algorithm for the executive devices of the TMS, reducing the weight, as well as the overall dimensions of the components, and conducting a detailed analysis of each component. It is also worth noting that the use of collaborative experimental research in the X-In-the-Loop environment will reduce the cost of the experiment, as well as, ultimately, the cost of the product, since with such an approach there is no need for a real test object for each company engaged in the development of one or another electric.