bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preliminary study of distribution of mechanical properties and mineral density by depth of liquid saturated carious dentine
Authors: Sadyrin E V , Mitrin B I , Yogina D V , Swain M V 
Published: January 2021

Abstract
Fissure caries in a form of brown spot lesion is a serious problem for patients. Having passed the dentine-enamel junction, cariogenic bacteria cause demineralization of dentine in its vicinity. Over time, the area of demineralization spreads deeper towards the pulp of the tooth, creating a gradient of strength characteristics in dentine. The aim of this work was to determine the mechanical properties and mineral density in the direction from the dentine-enamel junction to the dental pulp using nanoindentation and X-ray computed microtomography. The results can be used as control ones for the further research of remineralization techniques used in clinical practice.
Phase Diagram of Nanoparticles of Palladium-Platinum Alloys
Authors: Aref`eva L P , Dolgachev Yu V 
Published: January 2021

Abstract
Melting and crystallization temperatures of mesoscopic metal particles have been calculated within the framework of thermodynamics of surface phenomena and the electron-statistical method, for which it is necessary to take into account the dimensional dependences of the surface and interphase energies. All estimates were carried out in the model of heterogeneous melting in the presence of a skin layer. Phase diagrams have been constructed for binary Pd-Pt nanoparticles with solid core linear dimensions of 5 and 8 nm and a skin layer thickness of 2 nm. The surface and interfacial energies, as well as their temperature and size dependences, were estimated by a modified electronic statistical method. A comparative analysis of the results obtained using different expressions for the size dependence of the specific heat of fusion of nanoparticles is carried out. It was found that the shape of the diagram has significant differences from the phase diagram for the bulk phases of the metals under consideration. The main reason for the difference is the melting-crystallization hysteresis and the appearance of a smooth maximum on the liquidus and solidus lines. The maximum on the lines of melting and crystallization temperatures can be explained by a more pronounced size dependence of the interfacial characteristics of platinum. In accordance with the criterion that determines the more surface-active component, it can be concluded that with a change in the melting point ratios of pure components and lower values of the surface energy of palladium, a core (Pd) - shell (Pt) structure will form in nanoparticles.
Investigation of the fracture structure of a composite material after bending test by atomic force microscopy
Authors: Duka V V , Aref`eva L P , Mitrin B I , Pustovoit V N 
Published: January 2021

Abstract
The paper presents the results of a study of the surface fracture tested for bending at negative temperatures of a ferrite-martensite composite (FMC) obtained on the basis of K 02704 structural hypoeutectoid steel by atomic force microscopy. Metallographic studies of the sample were carried out on longitudinal sections. Investigations of microstructures were performed on optical microscopes Metam RV-22 and Neophot-21. Impact bending tests were carried out in accordance with ISO 148-1:2016. The quantitative assessment of martensite was carried out using the digital imaging program and amounted to 30%. A three-dimensional image of the fracture of the sample surface was obtained by atomic force microscopy (Nanoeducator II) in the semi-contact mode. An AFM study of the fracture surface showed that the data of optical and atomic force microscopy are in agreement. The three-dimensional AFM image of the surface fracture and its profiles, extracted in different areas, as well as the roughness parameters, show the presence of a dual line structure in steel.
Microstructure and elemental composition of multicomponent systems based on silicon, titanium and zirconium oxides
Authors: Blinov A V , Jasnaja M A , Kravtsov A A , Gvozdenko A A , Raffa V V 
Published: January 2021

Abstract
The paper presents the results of studying the microstructure and elemental composition of multicomponent systems based on silicon, titanium and zirconium dioxides. These systems are of great practical interest for the medical, food, and microbiological industries due to their unique optical, photocatalytic, and bactericidal properties. Studies have shown that multicomponent systems based on silicon, titanium, and zirconium dioxides obtained by the solgel method have an amorphous structure, while the samples exhibit a deviation from stoichiometry towards an increase in the oxygen content, which is explained by the presence of oxo-, hydroxo-, and aqua complexes. The structure and shape of multicomponent oxide particles are determined by the component that prevails in the system. The presence of additional components and possible chemical interactions between them determines the process of nucleation, which, in turn, affects the polydispersity of the obtained samples.
DLC coatings for tribotechnical purposes: features of the structure and wear resistance
Authors: Kudryakov O V , Varavka V N , Kolesnikov I V , Novikov E S , Zabiyaka I Yu 
Published: January 2021

Abstract
The article presents the results of metal-physical and tribological studies of carbon thin films - diamond-like coatings (DLC), obtained by vacuum ion-plasma technology. The most interesting results are the gradient distribution of the ratio of carbon electronic configurations sp3/sp2 over the depth of the coating, obtained by the XPS method. The structure of such a coating, as it approaches the substrate, transforms from DLC to amorphous graphite (GLC). This feature manifests itself in the mechanism of coating wear during tribological tests. Its wear occurs by the abrasion mechanism, similar to high-strength rubbers.
Diagnostics of gradient strains field in polymer composite material with built-in fiber optic piezosensor
Authors: Pan’kov A A 
Published: January 2021

Abstract
Description of design, principles and functioning of distributed optical fiber piezoelectroluminescent (PEL) sensors embedded in polymer composite structures for refined monitoring of inhomogeneous “gradient” strains fields inside structures is given. The informative light signal occurs due to the mechanical-luminescent effect caused by the interaction of the piezoelectric and electroluminescent elements (sectors of layers) of the sensor. Monitoring are found as a result of digital processing of the information spectrum of the intensities of the integral light signal at the output from the optical fiber taking into account the known dependences of the light output intensity of the each j-th electroluminophore on electrical voltage applied thereto. Mathematical models have been developed, settings and problem solving scheme on finding numerical values of transfer information and control coefficients of PEL sensors are given, and results of numerical calculation of transfer coefficients of sensor for case of small values of gradients of diagnosing strains field are presented.
Modeling and analysis of functional characteristics of QD-InAs/GaAs heterointerface with multi-barrier layers
Authors: Blokhin E E , Irkha V A 
Published: January 2021

Abstract
The article is devoted to the problem of studying the functional characteristics of heterointerfaces with quantum dots InAs by methods of mathematical and simulation modeling. A solution to the problem in the form of a developed mathematical model of a structure with quantum dots InAs with two types of barrier layers GaAs and AlGaAs is proposed. It is shown that using the quasi-drift-diffusion model in combination with the solution of the Schrödinger equation in the potential well of a quantum dot, it is possible to construct the energy structure of the layer-by-layer heterointerface design with the possibility of modeling functional characteristics, in particular, the spectral dependence of the external quantum efficiency and the dark current-voltage characteristic.
Growth of zinc oxide nanostructures by mass transfer through a micro-sized vacuum zone in a temperature gradient field
Authors: Irkha V A , Blokhin E E 
Published: January 2021

Abstract
This paper presents the results of studies on the controlled production of ZnO nanostructures with specified physical properties. It has been shown experimentally that by using the mass transfer of a substance through a micro-sized vacuum zone in a temperature gradient field, it is possible to grow quasi-one-dimensional ZnO nanostructures stochastically or orderly located on a substrate. The density of deposition of quasi-one-dimensional ZnO nanostructures is determined depending on the substrate material. It was found that the resulting ZnO nanostructures have good crystal perfection and stoichiometric compositions, and also have pronounced piezoelectric properties.
Information system “Graded coatings”
Authors: Krenev L I , Sadyrin E V , Nikolaev A L , Litvinenko A N 
Published: January 2021

Abstract
Functionally graded coatings are widely used to protect structures and machine parts from damage caused by mechanical and thermal loads. The information system “Graded coatings” was developed to help the researchers to design such coatings and also for expanding of the availability of tools for calculating and analysing of experimental data. The system was constructed for interactive data preparation and multi-parametric analysis of the results of numerical-analytical solution of mixed boundary value problems of crack theory and theory of elasticity and thermoelasticity for continuously inhomogeneous coatings of complex structure
Application of FPGA technologies for modeling hydrophysical processes in reservoirs with complex bottom topography
Authors: Leontyev A L , Chumak M I , Nikitina A V , Chumak I V 
Published: January 2021

Abstract
The article is devoted to the development and research of methods for accelerating calculations and processing input data for mathematical modeling of hydrodynamic processes in reservoirs with complex bottom geometry. The mathematical model of hydrodynamics considers: microturbulent diffusion; the influence of salinity and temperature. To increase the speed of calculations, it is proposed to transfer part of the computational load to reconfigurable computing systems (RVS). The paper also proposes an algorithm for adding input data by analyzing the existing database of environmental data, which was successfully verified analytically. The practical significance of the work is that a hardware implementation of the IP core was proposed, which allows solving systems of linear algebraic equations that arise when sampling the model of hydrodynamics of the Caspian Sea. It is experimentally established that the resulting implementation is characterized by low power consumption and is capable of processing large-dimensional matrices. The prospects of using the proposed algorithm are determined.
Use of modern technologies in assessing the stability and vulnerability analysis of information technology systems
Authors: Leontyev A L , Chumak M I , Chumak I V 
Published: January 2021

AbstractThe paper is devoted to the study of the possibility of applying the main methods of assessing the reliability of information technology systems, including a review of existing developments in this field and analysis of the basic principles of testing systems. Special attention is paid to methods for evaluating the reliability of software. This paper describes the main steps that should be taken by an attacker in a cyber-attack. Methods of vulnerability detection using graph theory are considered and methods of their elimination are shown. The possibility of using neural networks for traffic analysis in order to detect signatures is considered. The mechanism of DDoS attacks is considered and the main mechanisms of protection against them are analyzed. Mechanisms for changing the topology of information technology systems through the use of graph theory were tested on decentralized systems and showed a significant increase in the system’s resistance to unauthorized access. Mechanisms to prevent DDoS attacks through the use of neural networks allowed real-time tracking of unwanted content and reduced the time required to update databases of malicious signatures.
Modelling the pollutants transport in the “air-water” system of a shallow water
Authors: Lyashchenko T V , Lyapunova I A , Chistyakov A E , Nikitina A V , Filina A A , Leontiev A L 
Published: January 2021

Abstract
The work is devoted to the spread processes mathematical modelling of impurities in a reservoir in areas located far from river runoff. An aerodynamic processes mathematical model is proposed that takes into account a variety factors: increased air humidity, variability of atmospheric pressure and temperature, etc. The model discretization was carried out taking into account the partial filling of the calculated cells, which made it possible to significantly reduce the error at the boundary. For the calibration and verification of the pollutants transport model, the expeditionary research data were used.
Comparative analysis of identification of dynamic objects by scale-invariant feature transform and deep neural networks
Authors: Ivliev E A , Obukhov P S 
Published: January 2021

Abstract
The article is devoted to the development and analysis of methods of identifying dynamic objects. A system for identifying information from a luggage tag based on several neural networks with the SSD InceptionV2 architecture has been developed. These neural networks work with sufficiently high accuracy 82-95% and speed 7-10fps. Advantages and disadvantages of application of method of scale-invariant feature transform for identification of luggage tags are considered. The operability of the methods on real images has been tested.
Investigation of dynamic characteristics of regenerative pneumatic drive of filling and packing machine
Authors: Sirotenko A N , Grishchenko V I , Partko S A , Kilina M S 
Published: January 2021

Abstract
The article discusses the method of braking by back pressure of the output link of the pneumatic drive and the associated actuator. An increase in energy characteristics is achieved by accumulating compressed air in an additional volume. The mathematical model describes the braking process and includes equations of motion, pressure, and temperature. Preliminary setting of parameters of additional volume controls braking parameters. The solution of the mathematical model planned and conducted a computational experiment and obtained mathematical dependencies for the criteria of speed and energy consumption.
Digital meter of frequency instability and phase noise of high stable oscillators
Authors: Fedosov V P , Nsue Jacinto M B , Labyntsev A V 
Published: January 2021

Abstract
This paper discusses the measurement of frequency instability and phase noise of real oscillators. As part of this work, a device was developed in LabVIEW, which allows implementing the multiplier-conversion method (MCM), in the form of a subprogram for oscillations with a low level of frequency instability. Another device was developed, which allows the simulation of a signal with a given phase noise grade, for applying MCM to increase standard deviation as many times as is needed. The use of these devices confirmed the operability and efficiency of the MCM for increasing the oscillation instability by a given number of times. The research showed that in the case of oscillation with very high frequency stability, it is possible to increase this small instability by a concise number of times, using MCM, and thereby provide the possibility of measuring frequency and phase instability, by devices with a larger error than is required for the measurements of very small instability.
Dynamic control system for mine ventilation
Authors: Semenov V V , Fisunov A V , Nikishin I O 
Published: January 2021

Abstract
An optoelectronic dust meter, based on the fluctuation method, was proposed as a dust sensor for the dynamic control system of mine ventilation. The scheme of the proposed sensor can significantly reduce the error of continuous measurement of dust concentration to 5%, as well as determine the average size of dust particles in the studied environment, on the basis of which to predict the occurrence of occupational diseases. Dust sensors are installed at a distance of 10-15 meters from sources of dust release (lavas, conveyor lines, etc.), in working faces of a coal mine on incoming and outgoing streams at a height corresponding to the breathing zone of miners.
Research into storage processes in batteries to create highly efficient reversible hydrogen storage
Authors: Galushkin D N , Isaev I R 
Published: January 2021

Abstract
This paper has experimentally proved that hydrogen accumulates in large quantities in metal ceramic electrodes of alkaline accumulators during their operation. It has been found that hydrogen is not present in the metal ceramic electrodes of alkaline accumulators not yet in operation. It is shown that in alkaline accumulators with a service life of more than five years, the largest amount of hydrogen is present in their electrodes. Hydrogen is found to accumulate in oxide-nickel electrodes of alkaline accumulators, which have hydrogen absorption capacity of 13.4 wt%. Sintered nickel matrix of oxide-nickel electrode of alkaline accumulator was considered. The values of hydrogen absorption in this matrix are 20.2 wt%, the stored energy density is 44.018 kJ/g. The results obtained in the operation are three times higher than the previously obtained data, which are based on the use of traditional methods for reversible metal hydrides, such as magnesium hydride and complex hydrides. In addition, the results obtained exceed the values announced in the criteria for hydrogen storage systems developed by the US Department of Energy.
Methods for minimizing the error in selecting a useful signal in the presence of the «flip» effect of the approximating function
Authors: Marchuk V I , Hripkov G L , Nikishin I O , Shrayfel I S 
Published: January 2021

Abstract
The paper discusses the issues of minimizing the error in selecting a useful signal in the presence of the “flip” effect of the approximating function, which are solved by compensating for the approximation error by eliminating the “flip” effect by mirroring it relative to a certain line, which is determined by the methods proposed in this work. The proposed method for choosing a line for mirroring the estimate of the useful signal function has

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8 times smaller, with a spread of values that is characterized by

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which is more than 70 times less.
Thread milling errors
Authors: Yamnikov A S , Pozumentshchikov I K , Yamnikova O A 
Published: January 2021

Abstract
The study shows that thread milling (including internal threads) is one of the most forward-looking technologies that offers max thread cutting performance. The reasons are the shortest cut-in path equal to the thread depth, and the full thread profile machining time equal to the period of one revolution of the workpiece. The paper highlights that thread milling is an efficient, general-purpose machining process. In this study, we solved the thread profile error estimation problem. Thread milling with parallel workpiece and cutter axis was investigated with a milling simulation model. The optimal thread milling tool parameters for internal thread machining were found. The method efficiency was proven by measuring undercuts and overcuts in pipe thread milling. For instance, the thread error (overcuts/undercuts measured flatwise to the thread profile) diametral compensation does not exceed 0.0268 mm while the pipe thread tolerance G1.25`` is 0.36 mm.
Automation of thermal processing of quartz glass with the following computer treatment of the quality of siloxane communication
Authors: Dolapchi S M , Denisova O A 
Published: January 2021

Abstract
The strength characteristics and isotropic physical properties of quartz glass give broad prospects for its use as a resonator for navigation systems of aircraft, as well as for complex optical systems and automation elements. To obtain a sufficiently hard surface with the desired properties, it is necessary to create conditions for the occurrence of siloxane bonds - silicon and oxygen compounds. During the formation of such bonds, the process of polymerization and annealing of quartz glass, high-strength resonator samples are obtained. The quality of the resulting surface is determined by different methods - fractal geometry, recumbent drop and Vickers. In the presented material, the authors propose to use the recumbent drop method (distilled water was used). To obtain samples of resonators, a resistance furnace has been designed and constructed, which operates in an automated mode using a personal computer control. Also, a computer program “Droplet stacking method” was written in Delphi 7.0, which presents the results of monitoring the annealing process, including the surface annealing temperature and contact angle. The results of measurements and calculations can be recorded as a file and observed on the display. The program interface is intuitive and convenient for controlling the process of obtaining samples. In addition, to form a high-quality connection, a program was also written to determine the radius of the nucleus and the value of the Gibbs free energy, which is necessary for the formation of the nucleus. The experimental results obtained and the calculations performed by the lying drop and fractal geometry methods have demonstrated the agreement between the results within the error limits of the methods.
About the possibility of metamaterials application at the band–pass microwave filters designing with superwide pass transmission band
Authors: Budyakov A S , Cherckesova L V , Kleimenkin D V , Shokova Yu A 
Published: January 2021

Abstract
A band-pass filter with an extended operating frequency range based on composites - metamaterials is considered. Two design stages are presented, when, at the first stage, a two-stage microstrip filter on a resonator with a stepwise change in impedance, an SIR filter, is developed. At the second stage, the SIR-filter is remodified by adding to it a cell of mixed combined right-handed and left-handed transmission lines made of metamaterials. At lower frequencies, in the bandwidth, insertion loss is about 4 dB in the 3.1-4.2 GHz frequency range, due to the difficulty of meeting the impedance requirements of the mixed right-hand and left-hand transmission line, for all six phases throughout the ultra-wide frequency band is required. It was found that such methods are quite applicable for the design of other radio-electronic devices, in which impedance matching in an ultra-wide frequency band is required.