bluuebunny/crossref_metadata_2025 huggingface dataset:
Anomalous HCN emission from warm giant molecular clouds
Authors: Goicoechea Javier R. , Lique François , Santa-Maria Miriam G.
Published: November 2021

Hydrogen cyanide (HCN) is considered a good tracer of the dense molecular gas that serves as fuel for star formation. However, recent large-scale surveys of giant molecular clouds (GMCs) have detected extended HCN rotational line emission far from star-forming cores. Such observations often spectroscopically resolve the HCN J = 1–0 (partially also the J = 2–1 and 3–2) hyperfine structure (HFS). A precise determination of the physical conditions of the gas requires treating the HFS line overlap effects. Here, we study the HCN HFS excitation and line emission using nonlocal radiative transfer models that include line overlaps and new HFS-resolved collisional rate coefficients for inelastic collisions of HCN with both para-H2 and ortho-H2 (computed via the scaled-infinite order sudden approximation up to Tk = 500 K). In addition, we account for the role of electron collisions in the HFS level excitation. We find that line overlap and opacity effects frequently produce anomalous HCN J = 1–0 HFS line intensity ratios (i.e., inconsistent with the common assumption of the same Tex for all HFS lines) as well as anomalous HFS line width ratios. Line overlap and electron collisions also enhance the excitation of the higher J rotational lines. Our models explain the anomalous HCN J = 1–0 HFS spectra observed in the Orion Bar and Horsehead photodissociation regions. As shown in previous studies, electron excitation becomes important for molecular gas with H2 densities below a few 105 cm−3 and electron abundances above ~10−5. We find that when electron collisions are dominant, the relative intensities of the HCN J = 1–0 HFS lines can be anomalous too. In particular, electron excitation can produce low-surface-brightness HCN emission from very extended but low-density gas in GMCs. The existence of such a widespread HCN emission component may affect the interpretation of the extragalactic relationship HCN luminosity versus star-formation rate. Alternatively, extended HCN emission may arise from dense star-forming cores and become resonantly scattered by large envelopes of lower density gas. There are two scenarios – namely, electron-assisted (weakly) collisionally excited versus scattering – that lead to different HCN J = 1–0 HFS intensity ratios, which can be tested on the basis of observations.
New calculation method for tube cross-flow heat exchangers
Authors: Węglarz Katarzyna , Taler Dawid , Taler Jan , Marcinkowski Mateusz
Published: November 2021

A new method for thermal calculations of the cross-flow tube heat exchangers was proposed. The temperature of both fluids and the wall temperature are determined. The heat exchanger is divided into control volumes, in which outlet fluid temperatures are calculated by closed analytical formulas. Two examples of the application of the method for the calculation of two-pass cross-co-current and cross-countercurrent superheaters were presented. An exact analytical model was also developed for both superheaters to estimate the accuracy of the proposed method. The results of the superheater calculations using the developed method are in good agreement with the results obtained by the exact analytical models. The proposed method can be used to calculate heat exchangers with a complicated flow system in which the physical properties of fluids are temperature-dependent.
Radiation protection to patients in radiology: A review study
Authors: Jalilifar M. , Fatahi-Asl J. , Saba V.
Published: November 2021

The present paper aims at reviewing different shielding methods used for patients in medical imaging and investigating their merits and demerits. These techniques are generally classified into two groups including in-plane and out-of-plane shielding. Bismuth (Bi) shielding is a conventional in-plane shielding method used during CT examinations to protect radiosensitive organs. This method has reduced radiosensitive organs dose by about 34–68% during different CT examinations. However, it causes considerable degrading effects on image quality and for this reason AAPM recommended against its application in 2017. Recently, another in-plane shielding, named Saba shielding, introduced wherein all the shortcomings and deficits of Bi shielding have been resolved or fixed. Saba shielding reduces radiosensitive organs dose by about 50% without degrading image quality. Out-of-plane shields can decrease the patient dose by more than 55%. However, due to the low dose of the scattered radiation received by out-of-plane organs, in the case of applying out-of-plane shields such as gonad or thyroid shields, the risk and benefit of their usage should be evaluated.
YouTube as a Source of Patient Information on Myofascial Pain
Syndrome
Authors: Şan Ayça Uran
Published: November 2021

Introduction Myofascial pain syndrome is a local disorder characterised by
pathological myofascial constrictions and trigger points. One of the most
popular sources of internet-based information for patients is YouTube, which
provides a lot of videos related to myofascial pain syndrome, making it one of
the top clinical conditions searched for on the site. This study aimed to
examine the quality of the YouTube video content on myofascial pain
syndrome.

Method This study was designed as a cross-sectional study and used the
YouTube video sharing website as the main source of data. A search of the
relevant videos was performed by entering the words “myofascial pain
syndrome” in June 2021. Video characteristics were recorded, and the
quality of the videos was assessed according to the Journal of the American
Medical Association (JAMA) benchmark criteria, the DISCERN Scale and the Global
Quality Scale.

Results A total of 322 videos were evaluated, 186 of which were subjected
to analysis after applying the inclusion/exclusion criteria. The videos
were categorised into groups, with 10 (5.4%) falling into the
high-quality group, 16 (8.6%) into the intermediate quality group, and
160 (86%) into the low-quality group. The findings from the study showed
that the most popular videos, the highest number of video likes and the highest
number of video views were in the intermediate group, while the high-quality
group had the lowest popularity level, number of video likes and number of video
views (p ˂ 0.05).

Conclusions Although there are videos with high-quality content on YouTube
offering guidance to patients about the disease, it is important to keep in mind
that inaccurate and deficient information about the disease may also be present
on this platform.
Linear dispersion of Dirac fermions in (Cd1–x–yZnxMny)3As2, х+y = 0.2, у = 0.02, 0.04, 0.06, 0.08 solid solutions
Authors: Zakhvalinskii Vasilii S , Nikulicheva Tatyana B , Pilyuk Evgeny A , Nguyen Hong T.T , Lähderanta Erkki , Shakhov Mikhail A , Isaeva Natalia O , Kochura Alexey V
Published: November 2021

Based on the results of the Shubnikov-de Haas oscillations study in single-crystalline diluted magnetic semiconductors (Cd1−x−yZnxMny)3As2 (CZMA) with х + y = 0.2 and Mn content (у = 0.02, 0.04, 0.06, 0.08) at temperatures T = 4.2 to 30 K and magnetic fields B = 0 to 12 T under hydrostatic pressure p = 0 and 10 kbar, the values of the phase shift β, indicating the existence of the Berry phase in all samples were determined. Thickness of two-dimensional surface topological nanolayers in CZMA (х + y = 0.2) single crystals was defined. The rise in Mn concentration led to an increase in the concentration of charge carriers in the 2D surface layers n
2D
and a decrease in its mobility μ
2D. The reduced cyclotron mass m

с
(0)/m
0, depending on the Fermi wave vector k

F
, experimentally observed from the Shubnikov-de Haas oscillations, which was in a good agreement with the prediction theory of linear dependence and experimental results in topological insulator single crystals Bi2Se3 indicated that Dirac fermions were present in a diluted magnetic semiconductor CZMA system with х + y = 0.2. The damping of the Shubnikov-de Haas oscillations for pressures p = 0 and 10 kbar in the CZMA sample (х + y = 0.2; y = 0.2) was found to be associated with an amplitude decrease by spin splitting (Zeeman effect). From the analysis of experimental data, the effective Lande factor g = 7.63 and 7.87 and the band gap Δ =35.3 and 9.7 meV at p = 0 and 10 kbar, respectively, were obtained.
The energy spread effects of an electron beam on the evolution of Cherenkov free-electron lasers
Authors: Fares Hesham , Mahmoud Mohamed
Published: November 2021

An analytical approach is presented to calculate the growth rate coefficient which describes the intensity evolution of a Cherenkov Free—Electron Laser (CFEL) operating in the linear high—gain regime. The effects of the energy spread on the growth rate of a CFEL are addressed by introducing a relaxation time in our analysis. The relaxation process is associated with a deviation of electron velocities from the average value due to an energy spread whatever its source. Therefore, the relaxation time can present a unified point of view to describe the gain deterioration caused by the inhomogeneous broadening of energy spread effects. In this study, the plasma fluid and Maxwell formulations are used to describe the dynamics of electrons. It is found that the growth rate coefficient is saturated at a maximum value when the interaction time is approximately five times the relaxation time. When the electron relaxation is neglected (i.e., the relaxation time is infinitely long), the gain expression derived by our approach agrees adequately with those reported in other studies. It is shown that our gain expression is generalized and simple enough to provide fast and reliable assessment of the performance of CFEL devices.
Improved optoelectronic properties of Yttrium co-doped CdO:Zn thin films fabricated by nebulizer spray pyrolysis method for TCO applications
Authors: Sarath Babu R , Murthy Y Narasimha , Loyola Poul Raj I , Revathy M S , Chidhambaram N , Ganesh V , Algarni H , Yahia I S
Published: November 2021

To understand the effect of Yttrium (Y) co-doping with CdO:Zn towards optoelectronics applications, the thin films were coated by the nebulizer spray pyrolysis route. The microstructural studies (XRD) reveals that the crystallite size decreases from 20 to 15 nm with the increase of Y concentrations. The surface topography of the films has been strongly influenced by the Y doping which is evident from the AFM images. The presence of Cd, O, Zn, and Y has been confirmed through the EDX spectrum. The transparency is higher (81%) for the CdO:Zn-Y(1.5%) film. The decreasing trend in the values of the optical dielectric constant is observed with increases in yttrium content. The enhancement in the carrier concentration (12 × 1020cm−3) and reduction in the electrical resistivity (8.4 × 10−4Ωcm) have been observed for the CdO:Zn-Y(1.5%) film via the Hall-effect measurements. In addition, the heterojunction p-Si/n-CdO:Zn-Y(1.5%) photodiode was fabricated to understand the optical sensing properties. The current values of the fabricated photodiode are found to enhance as the intensity of the illumination increases from1.0 to 3.0 mW cm−2. Moreover, the photodiode exhibits the highest responsivity, detectivity, and external quantum efficiency value of 1.45 AW−1, 6 × 109 Jones, and 339%, respectively with excellent switching speeds. This work provided a guideline to develop a TCO layer and photodiode towards the applications of optoelectronic-based devices.
On non-monotonic temperature dependence of linear contact probability in atomic chains
Authors: Sharma Akariti
Published: November 2021

In this paper, we theoretically investigate the temperature T dependence of linear contact probability in atomic chains. In these chains, the transverse motion of the electrons is assumed to be confined in the harmonic oscillator confinement model. The intra-chain electron correlations are treated within both Hartree–Fock Approximation (HFA) and Random Phase Approximation (RPA). As artifact HFA correlation functions are used in the RPA perturbative calculations. Results are presented for numerically computed pair-correlation functions at different temperatures and electron densities. An enhanced singlet-state is observed in these chains at zero inter-electronic spacing which remains independent of T. At non zero inter-electronic spacing, shrinking of Pauli’s hole is observed with increasing T. Using the RPA, the short-range pair-correlation functions are found to be considerably modified at finite-T and contact probability shows non-monotonic dependence on T. Smearing of exchange-correlation hole is also observed above a critical value of T in the diffusion zone. We also estimate the strength of the coupling parameter up to what the RPA is capable of dealing with carrier correlations in atomic chains. This work may prove useful for density functional theory calculations as estimation of the exchange-correlation hole is imperative for exchange-correlation functionals.
Visible spectroscopy of highly charged tungsten ions with the JET charge exchange diagnostic
Authors: Thorman Alex , Litherland-Smith Edward , Menmuir Sheena , Hawkes Nick , O’Mullane Martin , Delabie Ephrem , Lomanowski Bart , Fontdecaba Josep Maria , Scully Shane
Published: November 2021

Since the installation of the ITER-like wall on the JET tokamak, visible emission from a broad range of tungsten charge states has complicated plasma ion temperature and toroidal rotation measurements. A plethora of charge exchange transitions, from ions up to W56+, and 21 suspected magnetic dipole transitions have been observed. In particular W39+ and W46+ charge exchange emission contaminates the long-established carbon measurement at 529 nm. Fortunately the wavelength and relative intensity of the tungsten charge exchange lines is predictable and their influence can be mitigated when they are included in the spectral fit. Neon based charge exchange measurements at 525 nm are now preferred on JET since the ITER-like wall, however in this case an unidentified tungsten magnetic dipole transition contaminates the spectrum when the electron temperature is low.
Fuel cells as a future of automotive industry: A review of current developments
Authors: Andriyashin S N , Shurov N I
Published: November 2021

Fuel cells are more and more applied in the automotive industry in recent decades. This applies to both special equipment, such as forklifts, and personal automobiles. They are already serious competitors for BEVs (battery electric vehicles) and will likely compete with ICE (internal combustion engine) vehicles in the future. This study provides an overview of the latest developments in the use of fuel cells in transport.
Computer simulation of a power source based on a bipolar pulse shaper for magnetron sputtering systems
Authors: Tyufanova AA
Published: November 2021

The research object is a pulsed bipolar power supply based on a bipolar pulse shaper of increased frequency for magnetron sputtering systems. The research subject is the electrophysical and electromagnetic processes occurring in the bipolar pulse shaper when it is operated with a magnetron sputtering system, as well as the control characteristics. The purpose of the paper is the possibility of creating a pulsed power supply with a power of up to several tens of kW, which makes it possible to increase the stability of the magnetron sputtering system. Besides, the outcomes of computer simulation of a power source based on a bipolar pulse shaper and control algorithm ensuring its stable and reliable operation in association with a magnetron sputtering system are reflected in the paper. The results show that the deviation of the output control characteristics of the bipolar pulse shaper from the analytically obtained characteristics does not exceed 3%. Circuit modeling is carried out in the Swicher CAD/LTspice software package. The mathematical SPICE models of the field-effect STY112N65M5 transistor, transistor IGBT of IRF4PF50WD and STTH8006 diode are taken from the websites of STMicroelectronics and International Rectifier manufacturers.
Determination of the charge and discharge modes duration effect on the LiFePO4 cells resource in the electric power source
Authors: Schurov N I , Dedov S I
Published: November 2021

The paper is devoted to the determination of the resource of LiFePO4battery cells when they are used as a primary source of energy in an electric vehicle. The analysis of the WLTC driving cycle from the point of view of the currents arising in the battery of an electric vehicle was carried out, its main parameters were revealed, such as: the duration and magnitude of the charge and discharge currents and the duration of the pause. The results of experiments on determining the resource of an 18650 cell at various load cycles are presented. It was found that cells loaded with a low current with a high switching frequency of the operating mode are subject to the greatest degradation. The lowest degradation rate was observed in cells loaded with low current with short-term charging modes. The result obtained will make it possible to more accurately determine the remaining life of the battery cells. Also, the data can be used to improve the algorithms of the BMS in order to extend the battery life.
Thermoelectric modular systems based on semiconductor elements of Peltier-Seebeck for vehicles
Authors: Feofanov S A , Chashchin S L
Published: November 2021

Elevations in technology of semiconductor materials allow for new vehicle systems use for improvement in the standard ones. One of the most promising materials for achieving an efficacy of more than 50% is polyaniline, which belongs to the class of conductive polymers that has semiconducting peculiarities. For instance, a new generation of semiconductor elements based on the Peltier-Seebeck effect makes it possible to use them to create thermoelectric generators, which means to use the thermal energy of the exhaust gases of internal combustion engines (ICE) to generate electrical power. The second area where Peltier-Seebeck semiconductor elements find application in automobiles are modular climate control systems. Due to the absence of moving parts and relatively small dimensions, they allow the creation of individual climatic zones in the car interior. An elegant design and technological solution is the placement of similar thermal semiconductor modules inside the driver’s and passenger’s seats, which makes it possible to transfer heat more efficiently and make climatic zones more apparent. The article considered engineering options for the design of climate control units based on Peltier elements and the creation of a prototype. The issues of integration into the vehicle on-board network and the features of power control are considered. The studies and results of this paper can contribute to improving the energy efficiency and technosphere safety of vehicles.
Instrumentation used for vibration monitoring on the supports of the tank scales of the port transshipment complex
Authors: Dubrovin R G , Nikolaev N I , Gerasidi V V
Published: November 2021

The main thing for rotating equipment is to measure vibration, since, in the process of irreversible state change, a chain of defects always occurs and at least one of them significantly changes the vibration of the equipment. Using tank scales for static equipment, the vibration measuring makes it possible to determine the actual values of the levels and compare them with the maximum permissible values set by the manufacturer or regulatory documents. Also, the measurement of vibration levels in the time signal allows determining resonant frequencies at which vibration levels significantly increase due to the coincidence of the natural frequencies of the equipment with external workers, which can lead to increased loads on the supporting metal structures, suspended equipment and subsequently to fatigue destruction of the latter. Results of the work: the excess of the measured vibration levels on the supports of the hopper scales No. 28.1 was recorded by vibration acceleration in pt.11 (longitudinal direction) from twelve measurements; the excess of the measured vibration levels on the supports of the hopper scales No. 28.2 was not recorded, but increased levels of vibration speed were observed in pt. 11 and pt. 12; excessive vibration levels at the same measurement points on different scales may indicate that it is necessary to conduct a survey of the operation of the valve mechanism for smooth running and to monitor the condition of the metal structure under the fourth supports; it is recommended to perform a repeated measurement of the vibration of the hopper scales after inspection and repair of the structures of the scales.
Mathematical model of a ferromagnetic lubricant in the presence of a porous coating in the bearing structure
Authors: Opatskikh A N , Novakovich M V
Published: November 2021

Based on the flow equation of a ferromagnetic liquid lubricant for a “thin layer”, the continuity equation and Darcy’s equation describing the flow of a lubricant in a porous body, an exact self-similar solution of wedge-shaped sliding support with a porous coating of the surface of the support ring is found, taking into account the dependence of the viscosity of the ferromagnetic lubricant and the permeability of the porous coating with the incomplete filling of the working gap. Analytical dependencies for the velocity and pressure fields in the lubricating and porous layer are obtained. Also, the main operating characteristics are determined load-bearing capacity and friction force. The numerical analysis of the theoretical results showed that the bearing capacity of the bearings can be increased by 8-12% in the range of the studied load-speed modes. At the same time, the coefficient of friction is reduced by 14-16%. To verify and confirm the effectiveness of the obtained theoretical models, an experimental study of a modified wedge-shaped sliding support on TP-22C, MS-20 oil and their mixture with various additives was carried out. As a result of theoretical and experimental studies, tribotechnical characteristics were determined that allow us to judge the presence of a long-term friction mode.
Features of an induction motor design taking into account the possible operation in the mode of electrical asymmetry of the windings resistances
Authors: Lavrenov E O , Temlyakova Z S , Vilberger M E , Toporkov D M , Temlyakov A A , Tolstobrova L I
Published: November 2021

The paper examines the operation of large high-voltage induction motors used as an electric drive of critical installations in enterprises with a continuous production cycle. The theoretical foundations of the appearance of a dip in the mechanical characteristic of an induction motor in the mode of winding resistances asymmetry are considered. The developed power supply device for an induction motor with torque dip compensation at electrical asymmetry of phase windings appears is presented. The necessity of introducing a service factor is formulated to take into account the decrease in the total level of the electromagnetic torque in such operating modes, which is carried out at the stage of the motor design beginning.
Simulation and physical modelling of synchronous electric drive for electric and hybrid vehicles
Authors: Malyshev A N , Panarin A N , Debelov V V , Mizin M D
Published: November 2021

The article presents the theoretical foundations of the device and the principle of control of a power electric drive. An overview of the main structural elements and the requirements for the electric drive are made. Power electric drive control systems using inverter converters are considered: frequency-current control based on a current inverter; frequency-current control based on a voltage inverter; direct torque control; vector field control. The main provisions of the use of simulation and physical modeling in the development of an electric drive are presented. On the basis of the previous analysis, the best solutions allowing modeling the electric drive have been selected. The choice of the element base has been substantiated and the development of a physical model has been carried out.
Thermotechnical tests of an electronically controlled main high-speed engine of a marine vessel
Authors: Gerasidi VV , Lisachenko A V , Nikolaev N I
Published: November 2021

Thermotechnical tests of the main engine after a malfunction for putting it back into operation under the supervision of the Register inspector are presented in the paper. The electronically controlled high-speed Caterpillar C32 engine on the port side with an output of 1000 kW is described.Experimental studies of the value influence of thermaland vibration parameters on changes in the engine technical state are carried out during thermotechnicaltests. The experimental research methodology includes a classical approach to conducting such tests and a contemporary method with remote data transmission to the office of the vessel owner’s company.The accumulated practice in conducting experimental studies of the technical condition control by the in-place repair method of diagnostics makes it possible to move from classical approaches of technical operation to new ones included in the remote control and monitoring system of vessel technical means of autonomous ships in operation.The conducted studies have shown that the obtained values of the thermal engineering and vibration parameters do not exceed the maximum permissible values specified by the manufacturer.The results of the experimental study of Caterpillar engines demonstrate the defect initiation in one of the engine mounts by exceeding the values of vibration velocity.The conducted experimental studies of vessel technical equipment by the in-place repair method of diagnostics of marine vessels in operation are the basis of the control system of autonomous ships.
Applying detailed chemistry for the dual-fuel engine combustion process simulation using CFD approach
Authors: Grinev V N , Kozlov A V , Zuev N S
Published: November 2021

Modern research in the area of internal combustion engines is focused on searching and investigating the technologies that will improve fuel efficiency and decrease emissions. The application of dual-fuel engines is considered a potential solution to these problems. In the dual-fuel engine, the natural gas-air mixture is ignited by a small amount of diesel fuel directly injected into a combustion chamber. This paper aims to develop a detailed chemistry mechanism for 3D simulation of the combustion process of a dual-fuel engine, providing sufficient convergence with the experimental data. It should be noted that sufficient convergence must also be provided in terms of such parameters as pilot fuel ignition delay and premixed air-fuel mixture flame propagation speed. In the course of the research, the analysis of the most commonly used detailed chemistry mechanisms for calculation of the combustion process and mechanisms’ disadvantages was performed. The results obtained with the use of the detailed mechanisms were compared with the results obtained without using detailed chemistry and with the experimental data as well.
Interface for indication and remote control of an unmanned vessel in automatic and manual modes
Authors: Burylin Ia V
Published: November 2021

The article proposes a method for organizing the communication interface of an unmanned vessel and its operator. The interface contains manual controls for the course and speed of the vessel by regulating the angle of the rudder blade shift and the speed of rotation of the propeller shaft, an automatic system for keeping the vessel on a given trajectory for the purpose of navigating the vessel in automatic and manual modes. The interface comprises a system for obtaining filtration, storing the required kinematic and navigation data for identifying mathematical models of the vessel’s movement and the functioning of the autopilot. The interface allows adjusting the PID controller for automatic guidance of the vessel along the trajectory in real time to optimize automatic control, to correct the readings of the GPS and the Earth’s magnetic field sensors, to calibrate the Earth’s magnetic field sensor. The interface includes graphic and digital fields for displaying kinematic and navigation data on the vessel, autopilot and information on the operation of the operator-vessel complex. The interface allows the exchange of data between the operator and the vessel by means of a data transfer protocol via TCP-IP stack protocols on the radio frequencies of public Wi-Fi networks. The interface is created by means of appdesigner tools on the MATLAB platform.
Control of mobile equipment for the processing of marine shaft lines
Authors: Syusyuka E N , Kh Amineva E
Published: November 2021

The purpose of the research is to develop solutions for mobile equipment control in the processing of marine shaft lines; to solve the issues of geometric accuracy of processing; to create a corrective program to address the issues of accuracy of the geometric parameters processing; to give reasons for the application of linear electrohydraulic step drive (LEHSD) in mobile equipment control. The analysis of schemes and mathematical dependencies for calculating the trajectory of the tool movement of a mobile machine when processing shaft lines is carried out; the choice of the optimal zone for finishing the shaft line, taking into account the beats. The object of the study is a ship shaft line. The paper presents an original scheme of rotation of the shaft line section, as well as schemes for changing the position of the shaft line during processing; justifies the possibility of using a linear electrohydraulic step drive (LEHSD) with a corrective program for processing taking into account automatic measurements and a specified error.
Evaluation of reliability of quickly repairable components of transshipment machines and mechanisms
Authors: Ablyazov E K , Deruzhinsky G V , Ablyazov K A
Published: November 2021

When calculating the reliability indicators of transshipment machines and mechanisms, the required values are not always obtained explicitly due to systematic difficulties (complex distribution laws) or limited initial data. The optimal stock of spare parts for transshipment machines and mechanisms depends on the reliability indicators, and the nature and intensity of their use. Downtime due to the failure of transshipment machines and mechanisms used for ship handling leads to greater losses than downtime of these machines in the warehouse. Failures of transshipment machines and mechanisms can be due to the failure of non-repairable and quickly repairable components, and those with a long repair time. To calculate the main reliability indicators of quickly repairable components, the most common laws of distribution of random variables were employed. The paper considers the methodological aspects of the probabilistic reliability estimate of quickly repairable components of transshipment machines and mechanisms.
Assessment of the impact of waves on the steering of the vessel by deviations from the given line
Authors: Yudin Yu I , Boran-Keshishyan A L , Perevozov V V
Published: November 2021

Steering by deviations involves a significant reduction in the influence of the “human factor” on the final result of the steering. Obviously, this can be achieved by automating the process of steering the vessel, including when performing mooring operations. At the same time, the participation of the boatmaster in the steering process is not excluded. Summarizing the existing approaches to automating the process of controlling the movement of the vessel, it is necessary to pay attention to the intellectualization of the entire process of steering the vessel, as an actual scientific direction of modern science in the field of navigation. Intellectualization is a higher level of improvement of steering of the vessel, it involves the use of innovative ideas for the implementation of steering processes. In particular, these ideas are based on the use of a method for steering by deviations from a given line (GL) of two points spaced along the length of the ship, at which navigation information sensors are installed that determine the kinematic and dynamic parameters of the ship’s movement, namely, satellite navigation system receiver indicators and inertial sensors. To implement this method of control, both the main means of steering the vessel and the propulsion and steering complex, which includes active control means, can be used. The use of these and (or) other controls depends on the specific purpose of controlling the movement of the vessel.
Using telematics data to support effective solutions for tracking and monitoring the power system condition of unmanned vessels
Authors: Kondratyev S I , Epikhin A I
Published: November 2021

The paper studies the prospects of using telematics data to support effective solutions for tracking and monitoring the condition of the power supply system (PSS) components of unmanned vessels (UV) through the determination of positioning and, accordingly, operating time of PSS components. The paper attempts to describe one of the modules of the proposed integrated telematics system for UV monitoring, diagnostics and control. For practical implementation of telematics for unmanned merchant vessels, an algorithm has been developed to diagnose the technical condition of PSS components based on the operating time and condition of the units and components of the UV PSS. The results obtained by the algorithm show the technical condition of the observed technical equipment, time of its operation, and justify the need for repair or its complete replacement. The block diagram presents the algorithm that employs a minimal set of data to determine the use of technical equipment for further planning of its preventive maintenance. The paper provides the graphical interpretation of data on the time of PSS components operation and an example of displaying the interface of the remote operator of the UV. It is proposed to use telematics for tracking and monitoring the UV PSS operation in order to improve the quality of equipment maintenance, provide rational use of resources, extend its service life, and plan the repair time. In the future, it is proposed to create an integrated intelligent system based on telematics data, which allows the UV control and monitoring of the technical condition of its equipment.
Mobility of vehicles for transportation of heavy indivisible load in the Far North and methods of mobility estimation
Authors: Evseev K B
Published: November 2021

The article presents a hierarchy of performance properties of vehicles for the transportation of heavy indivisible goods. Different methods can be used to determine the performance properties measures. The article presents the measurers of performance properties, the numerical values of which are obtained by using the method of mathematical modelling and simulation, the method of natural mathematical modelling and experimental methods of evaluation. The article identifies the problem of logistics in the Far North and in regions with no road infrastructure. The question under discussion is a burning question. The solutions to the problem have been discussed. One of the solutions to the problem is the development of new vehicles for the transportation of heavy indivisible loads in the Far North. For each vehicle it is necessary to take into account its functional purpose. Only a certain set of the most important perfomance properties should be taken into account. The most significant properties characterizing the mobility property are determined.
Efficiency enhancement of the vehicle fuel tank ventilation system by improving its architecture and design
Authors: Glaviznin V V , Ter-Mkrtichyan G G , Mikerin N A
Published: November 2021

Hydrocarbon emissions from fuel evaporation contribute significantly to the total emissions of harmful substances from vehicles with forced spark ignition. To meet the legally established standards for limiting hydrocarbon emissions from evaporation, all current vehicles use fuel vapor control systems. The design of the system can vary and depends on the sales market of a particular vehicle. This article describes the development of this system for the market of the Russian Federation, as well as optimization for promising sales markets with more stringent environmental requirements.
Modeling and development of a fundamentally new way of landing a quadcopter on inclined surfaces
Authors: Olenko F F , Malakhov S O
Published: November 2021

Methods and software and hardware for modeling and developing a fundamentally new way of landing a quadrocopter on inclined surfaces are discussed in the paper. The current state of the project under elaboration is conditioned and described. Various approaches to the solution are feasible due to the complexity of the considered issue. Solutions can differ both in the distribution of control functions between the ground control station and the quadcopter itself, and in the choice of principles that can be used as the basis for the control system and determine its design and dynamic characteristics. Simulation and testing processes demonstrate that reverse thrust alone can increase the landing zone of an average mass quadcopter, almost doubling the maximum tilt angle at which a landing maneuver is made, thus, allowing for a high vertical speed landing. It is clearly shown that low-power adhesion mechanisms such as electrical adhesion, switchable magnets, grippers or dry glue are activated after landing, allowing it to stay on the surface after the back thrust has ceased. This can be useful in situations where sudden interference is likely to occur. Such a result is achieved using a classic quadrocopter as DJI F450 without adding any equipment.
Unmanned navigation system
Authors: Aleksanyan A K
Published: November 2021

After Lockdown - 2020, the unmanned navigation system began to be more actively developed. In a pandemic, it became clear that the modernization of ships, namely the automation of most operations, would reduce the size of the crew. This will reduce the number of jobs; on the other hand, this will ensure safety, which, today, is a priority. In addition, the introduction of a system of unmanned navigation will require a revision of the professions of seafarers, there will be a demand for highly qualified personnel, which will contribute to the emergence of new specialties in higher educational institutions. The sources for writing the article were the regulatory legal acts regulating the activities of the Maritime Law and the data of companies working in this area, taken from open Internet resources over the past 5 years. The article provides an overview of the unmanned navigation system market as a separate segment of the shipbuilding market that has significant prospects. A SWOT analysis of the implementation of the unmanned navigation system was carried out, the opinions of independent experts were considered. During the study, it can be argued that all economically developed countries are trying to switch to a system of unmanned navigation, but the main limiting factor for all is the issues of legal regulation.
Navigation system for unmanned vessels using a navigation buoy
Authors: Andryushechkin Y , Butsanets A , Karetnikov V , Ol’Khovik E
Published: November 2021

Nowadays the floating aids to navigation are being actively developed for remote control of the buoy location. The modern technical level allows building a buoy with the functions of monitoring the environment and transmitting the received information to coastal services. This task is becoming more urgent in connection with the development of unmanned vessels. The paper considers the results of field tests of an operating navigation buoy with special navigation equipment. The buoy is designed for information support during field tests of unmanned vessels and water transport facilities in the test water area in the Volga-Baltic basin of the inland waterways of the Russia Federation. Full-scale tests of special navigation equipment were carried out in accordance with the developed program and test procedure. The tests included the validation of the receipt of data from special navigation equipment to an external server via LTE mobile networks, assessment of the accuracy of positioning by means of navigation equipment, assessment of the percentage of data loss during transmission and validation of data visualization on an interactive map displayed in an Internet browser.
Logical-probabilistic assessment of the occurrence of destruction during intersystem interactions in the electrical system of the seaport
Authors: Litskevich O N , Litskevich A P
Published: November 2021

This article solves the problem of a quantitative assessment of the occurrence of destruction in the intersystem interactions of the transport system and the electrical system of the seaport, in the conditions of the technological process in the seaport, which indicates its significant impact on the electrical system, as a result of which the reliability of the berthing power line is significantly reduced. The intersystem interactions that occur during the implementation of the technological process, as experience shows, are the causes of critical situations that occur at the border of areas of different physical nature, and the consequences are recorded, in the case under consideration, in the electrical system. A mathematical model describing intersystem destruction in quantitative form is presented in this paper using a logical-probabilistic model that reflects internal and external relationships. In the object under study, the destructive cause (collision) and the consequence (accumulation of electrical damage in the insulation of the cable line) are in the same object (the mooring power supply unit), and this is limited to the effects of intersystem destruction. In such a statement, the object of power supply of the technological process and equipment is considered as a composite object containing a cable line and an electric contact column. The problem being formulated is an important and relevant scientific task, which includes not only the question of identifying the causes of increased electrical wear of the power line, but also the development of methods for obtaining quantitative results, and in practical terms also involves the diagnosis of the technical condition of electrical equipment and timely preventive maintenance.
Implementation of the control algorithm of the traction electric equipment
Authors: Lysenko D A , Yu Konyukhov V , Astashkov N P
Published: November 2021

Currently, in various fields of science and technology, there is a fairly large number of methods for predicting reliability indicators, which differ in the set of tasks to be solved and the features of the mathematical apparatus used. When developing a methodology for calculating the reliability of an electric machine, one of the main stages is the development of a mathematical model, in which it is possible to take into account the factors, the impact of which directly affects the technical condition and the level of operational safety. Taking into account the disturbing influences during the implementation of the technological process is possible provided that the means of automation are used. The performed analysis of statistical data on traction motor failures made it possible to substantiate the advisability of warming up, since a significant number of electrical part failures occur in the autumn - winter - spring periods of time. This feature of the distribution of failures is to a certain extent due to the direct wetting of the insulation and a decrease in its dielectric strength. This process is associated with a sharp drop in external and internal temperatures when placing the locomotive at the depot, which contributes to the appearance of condensate on the insulation, its further destruction. The measure proposed in the article for warming up traction electrical equipment is aimed at an integer reduction in the failures of the electrical part of the electric motors under consideration.
Research and Implementation of Browser Table Layout Algorithm
Authors: He Weiwen
Published: November 2021

Refer to the table’s feature, the paper advances a kind of table model, and then introduces how to convert the table into the table model, and gives a table layout algorithm based on the table model and the characteristic of the table layout in an embedded browser. At last the paper emphatically introduces the table layout algorithm that can be used to resolve the nested table layout and prevent the data out-flow the table.
Research on Identification of Consumer Product Quality Safety Factors Based on Improved FCM Algorithm
Authors: Kuai Yong , Wang Haiyan , Wang Yanfeng , Xu Yingcheng
Published: November 2021

In view of the shortcomings of FCM algorithm, the membership degree and the cluster category number are improved to perfect the FCM algorithm. The performance of the improved algorithm is verified by a case of consumer product quality as a data source, and the results show that with the improved algorithm, both clustering accuracy rate and F value are improved.
An Analysis of Internet Enterprise Value Evaluation Method Based on ARIMA
Authors: Chen Ling
Published: November 2021

With the rapid development of the times, the Internet has been deeply integrated into various fields, and many Internet companies have emerged at the historic moment, and economic activities such as mergers, reorganizations, acquisitions, issuance and listing, equity swaps, mortgages, bankruptcy and liquidation of Internet companies have also increased frequently. This has led to more and more value evaluation activities related to Internet companies, and the business model of Internet companies is different from traditional companies, so traditional corporate value evaluation methods cannot fully meet the special requirements of Internet company value evaluation. Therefore, we need to establish a sound Internet enterprise value evaluation system, and use more scientific and reasonable evaluation methods to ensure the interests of all parties to the transaction. Starting from the operating characteristics of Internet companies, this article analyzes the characteristics and difficulties of Internet corporate value evaluation, clarifies the effectiveness and limitations of the income method in Internet enterprise value evaluation, introduces the ARIMA model to improve the traditional income method and takes NetEase as an example. This method is applied to practice to verify its feasibility. So as to provide a scientific and reliable reference basis for Internet enterprise value evaluation.
Research on the Application of Adaptive Genetic Algorithm in Software Unit Security Test Simulation
Authors: Ge Xuefeng
Published: November 2021

At present, the security test and simulation of software unit mainly focuses on several links, such as software control structure amelioration, software process alternating quantity model control and model inspection tech, and there are still many shortcomings, such as high missed inspection rate, difficult to effectively guarantee the needs of practice, etc. Based on this, this paper first analyses the purpose and principle of software unit security test and simulation, then studies the utilization of ameliorated genetic algorithm in software unit security test simulation, and finally gives the simulation results analysis of software unit security test based on AGA.