bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural features of the near-surface layers of highly diluted aqueous solutions
Authors: Shostka V I , Shostka N V , Halilov S I , Vershitsky V I 
Published: February 2021

AbstractParticular importance currently is given to highly diluted aqueous solutions due to the fact that not only the presence of clusters, but also more complex structures – associates, bastons, etc., have been found in them. However, the phenomenon of the appearance of new physicochemical, spectral, diffraction, refractometric and other effects related to heterogeneity in the changing inhomogeneous structure of the surface layers of aqueous solutions is not fully understood. The paper presents the results of vertical laser sensing of drops of hydrophilic substances highly diluted in water, which made it possible to detect clathrate nano-formations in various combinations, the nature of which is still insufficiently clear. We studied droplets of distilled micellar water, hydrogen peroxide, an aqueous solution of glycerol, ethanol, etc. At low concentrations of hydrophilic substances in aqueous solutions their molecules are embedded into the interstices of the water lattice without causing destruction of its structure. It is found that the dissolution mechanism continued only to a certain critical concentration after which “saturation” occurred. A further increase in the content of dissolved substances in aqueous solutions leads to the destruction of the ordered structure, and the excess molecules of the hydrophilic substance, combined together, form complex aggregates or their “islands”.
Development and investigation of micro- and nanostructures of metamaterials to form the necessary characteristics and coefficients of piezoelectric elements
Authors: But V S , Kobelev A A , Karlin E S , Karpeev S V 
Published: February 2021

Abstract
The development and research of micro and nanostructures for the manufacture of ultrasonic piezoacoustic elements has been carried out. The structures obtained in this work have practical applications for the manufacture of piezoelectric and piezoacoustic elements, in particular, for using in liquid flowmeters as receivers and emitters of an ultrasonic signal. A structure of nanocells was obtained that was different from standard piezoelectric elements (disk, cylinder), but with the same coefficients, characteristics, and radiation pattern.
Analysis focused image formation in double exposure speckle photography
Authors: Osipov M N , Sergeev R N 
Published: February 2021

Abstract
This paper presents the theoretical and experimental results of the analysis of the formation of the focused image in a double-exposure speckle photography. Theoretical analysis of the formation of the focused image in double-exposure speckle photography was carried out using the Vander Lugt method. It is shown that as a result of the summation of speckle structures displaced in the space of the photographic plates, moiré fringes are formed in double-exposure speckle photography. Experimental results confirming theoretical studies are presented.
Simulation of light focusing by a dielectric microcylinder with a metal film and gap on shadow side
Authors: Savelyeva A A , Kozlova E S 
Published: February 2021

Abstract
In this work, using the FullWAVE software package, numerical simulation of focusing of TM-wave with a wavelength of 633 nm was performed. It is shown that a dielectric microcylinder made of polyester with a radius of 2.1749 of wavelength coated on the shadow side with a silver film of 90 nm with a 100 nm hole, allows to get a focus with a maximum intensity of 1.37 times more (10.61 a. u), than a conventional dielectric cylinder (7.73 a. u).
The formation of an array of photonic nanojets by steps with square profile
Authors: Zaitsev V D , Stafeev S S 
Published: February 2021

Abstract
Modeling the finite-difference time-domain method (FDTD) using the software package FullWAVE focusing Gaussian beam width of 5.4 um and a wavelength of 0.633 um using a binary grating made of silica (refractive index 1.46) showed that the individual steps relief near its output surface form the focal spots - photonic nanojet. This photonic nanojet bent at the wavefront tilt.
Multifunctional fiber optic system for microwave signals transmitting in frequency range from 0.135 to 40 GHz
Authors: Pchelkin G A , Yu Rud V , Davydov V V 
Published: February 2021

Abstract
In article of the developed design of a fiber-optic system for transmitting microwave signals in radar is presented. The using the developed design of a fiber optic transmission system of microwave signal allows to increase the range of operating frequencies of the radar at least twice as well as its functional capabilities. The new method of realization design of a fiber optic transmission system of microwave signal is proposed. Its use allowed to reduce in the fiber optic system, the number of functional blocks in this frequency range of the radar work on the compared to previously used designs. The experimental research results are presented.
Modelling of temperature fields in DP1000 steel during laser treatment using diffractive optical elements
Authors: Bielak R , Murzin S P , Liedl G , Otto A , Kazanskiy N L 
Published: February 2021

Abstract
Diffractive optical elements (DOEs) with their unique properties allow to form a predetermined beam intensity profile in the focal plane. The use of DOEs in laser material processing technologies reveals new possibilities for controlling the properties and operational characteristics of processed parts. The beam intensity profile formed by DOE is presented in the form of an analytical expression that was used to set a surface heat source for modelling thermal processes in DP 1000 steel. Experimental studies of samples under laser heating were performed. Simulation output results correlate well with the experimental data. The proposed simulation model, based on a precise heat input definition, is an intermediate step to the final goal, which is the prediction of structural changes in the zone of laser beam irradiation.
Experimental study of spatial frequency transition of laser induced periodic surface structures
Authors: Fuerbacher R , Liedl G , Murzin S P 
Published: February 2021

Abstract
This study shows the influence of laser fluence and pulse number on the spatial frequency distribution of laser induced periodic surface structures (LIPSS) on a stainless steel surface. Also the transition of LIPSS to larger self organized, periodic, cone-like structures has been investigated. The experiments were carried out using a Ti:Sapphire femtosecond laser system with 800 nm centre wavelength, a pulse duration of 30 fs and a repetition rate of 1 kHz. Experiments have been carried out on flat, cold-rolled stainless steel surfaces (1.4301) by variation of the laser output power and feed rate. It could be shown, that the transition of low spatial frequency LIPSS (LSFL) to high spatial frequency LIPSS (HSFL) is a continuous process, strongly depending on the laser single pulse fluence and the pulse number. At higher accumulated fluences the transition of LIPSS to larger self organized structures could be observed. As a result, hierarchical structures were created with micrometer-sized cones at the bottom and nanometer-sized LIPSS on top. By further increasing the accumulated fluence, the grooves between the micro structures are widened until the ablation threshold of the alloy is reached. These hierarchical structures could be of considerable value in improving wetting properties of technical surfaces.
Silicon subwavelength axicons for terahertz beam polarization transformation
Authors: Pavelyev V S , Degtyarev S A , Tukmakov K N , Reshetnikov A S , Knyazev B A , Choporova Yu Yu 
Published: February 2021

Abstract
The diffractive optical element (DOE) for transforming of linearly polarized THz radiation beam into a cylindrically polarized beam is investigated. Optimal diffractive microrelief height is determined by numerical simulation.
Academician Evgeny Pavlovich Velikhov and computer optics
Authors: Kazanskiy N L 
Published: February 2021

Abstract
The article describes the role played by Academician Evgeny P. Velikhov in the development of the scientific direction “computer optics”. It talks about the creation of the journal “Computer Optics”, the establishment of the Research & Education Center “Spectrum”, the support of the Image Processing Systems Institute of the RAS.
Determining parametric functions kinetic constants using the decomposition method
Authors: Ismagilova A S , Khamidullina Z A , Spivak S I 
Published: February 2021

Abstract
The purpose of this work is to automation of the informativity content analysis of kinetic parameters based onde composing a chemical reaction independent route. The software for determining the basis of nonlinear parametric functions of kinetic measurements for the mechanisms of complex chemical reactions is developed and described.
Investigation of the effect of continuous operation of the polymerization process in the presence of Ziegler-Natta catalysts on the molecular characteristics of the product
Authors: Miftakhov E N , Mustafina S A , Mikhailova T A 
Published: February 2021

Abstract
A mathematical model of the process of producing polyisoprene in the presence of various catalytic systems of the Ziegler-Natta type is constructed in the article. When developing a mathematical model, the polycentric nature of the applied catalytic system was taken into account and the modular construction principle was applied, which allows calculations to be made both for the batch mode of the process and for the continuous mode. An analysis was also made of the influence of the hydrodynamic regime on the polymerization rate and the molecular characteristics of the resulting product using the example of a titanium-containing catalyst system.
The probabilistic model of search and detection of ground objects using unmanned aerial vehicles in difficult weather conditions
Authors: Kuznetcov I E , Kuznetcov A A , Baklanov I O , Strashko O V 
Published: February 2021

Abstract
The paper proposes the model of search and detection of ground objects in difficult weather conditions with the use of unmanned aerial vehicles. The model is based on the probabilistic approach and allows assessing the quality of reconnaissance missions taking into account the influence of the most significant meteorological values and weather phenomena.
Catalysts of the catalytic cracking process and development of a fourteen-component kinetic model
Authors: Bikbova G R , Mannanova G I , Gubaydullin I M 
Published: February 2021

Abstract
The catalytic cracking process is specific and depends on several technological factors such as temperature, pressure, type of catalyst and reactor, and contact time. This article presents a review of foreign industrial zeolite-containing catalysts RDM SWM, and Russian microspherical catalyst “Oktifayn”, granular cracking catalysts “adamant”. On the basis of experimental and production data it is possible to conduct mathematical modeling of catalytic cracking process, and to select constants of rates of chemical transformations for each of types of catalysts.
Reorienting nanosatellites to a predefined attitude using angular displacements of movable modules
Authors: Doroshin A V , Eryomenko A V 
Published: February 2021

Abstract
The dynamics of the spatial motion of a nanosatellite with a movable module tilted relative to the main body is considered. Control laws are developed to implement attitude dynamics with suppressing the precession-nutational motion, as well to bringing the nanosatellite into a predefined spatial orientation.
Program for modelling the kinetics of chemical reactions in a cascade of reactors
Authors: Karamova A 
Published: February 2021

Abstract
An algorithm for solving the direct kinetic problem in a cascade of reactors is developed, based on explicit and implicit numerical methods for solving the Cauchy problem. The program is implemented in Borland Delphi environment. There are ability to compile kinetic models of various catalytic processes based on the law of the acting masses in the software package. The software package can be used to simulate the kinetics of an industrial process in a cascade of reactors of ideal mixing of periodic action and ideal displacement.
Using ROC analysis to confirm an algorithmically established diagnosis of lichen planus
Authors: Serikova E , Kalaev V , Serikova O 
Published: February 2021

Abstract
The use of ROC analysis allowed the authors to determine cytogenetic criteria to confirm the diagnosis of lichen planus, obtained by selecting the most informative features and interpreting the micronucleus test in buccal epithelium, calculating their critical values, sensitivity and specificity for use as diagnostic tests. An increase in the number of cells with micronuclei in the lesion of lichen planus is a sign of genetic instability, which can trigger the process of their malignancy. Recognition of nuclear aberrations against the background of nuclear destruction makes it possible to diagnose lichen planus in patients).
Criteria for spin instability based on the node distribution in Trace-transform of the SHS combustion wave chronogram
Authors: Grigoryevskaya A , Gulyaev P , Jordan V , Shmakov I 
Published: February 2021

Abstract
The article presents the results of the Trace analysis of three types of experimental chronograms of the SHS combustion wave in ignition, extinction, and stable propagation modes. It is shown that the use of the differential chronoscopy (DCS) method allows one to reliably determine the moment of occurrence of the spin instability of the SHS wave by the presence of local maxima of the T-functional, when the trace line exactly coincides with the image of the combustion wave front on the DCS map. It was found that in the stable spin combustion mode, the DCS map is a set of periodic isoclines, and this leads to the appearance of point nodes in the 2D image of the Trace transform. As a criterion for recognizing spin instability, we selected the feature of the appearance of local maxima in the central transverse region of the Trace transform spectrum. It is concluded that spin instability is characteristic of the transition from thermal to diffusion instability in the presence of a hysteretic dependence of the burning rate on temperature.
Algorithms of direct simulation of chemical reaction under conditions of uncertainty of initial data
Authors: Zigangirova D R , Mustafina S A 
Published: February 2021

Abstract
Accuracy of measurement of initial data is important in simulation of chemical processes. Distortion of the original parameters can have a significant impact on the result of calculations. In addition to this error, there is also the error of the chosen method of solving the problem. In this article discusses the methods of interval calculations, their using for measurement of initial data and determination of errors in solving problems. Algorithms were implemented in Pascal programming language in Pascal ABC.NET development environment, visualization of solution was obtained with using Mathcad system.
Mathematical modelling of heating features of a cylindrical surface under plasma deposition
Authors: Bogdanovich V I , Giorbelidze M G 
Published: February 2021

Abstract
Mathematical model for temperature determination in a system ‘coating – base’ under plasma deposition of a powder material on the internal cylindrical surface has been developed. Mathematical model takes into account transformation of Gauss heat source, relative motion velocity of a plasmatron, and an angle of a plasma jet relative to the deposition surface. Effect of process variables of deposition on the process thermal stress and quality of plasma coatings has been analyzed.
Hydrodynamics in counterflow cooling tower with corrugated inclined contact elements
Authors: Dmitriev A V , Madyshev I N , Khafizova A I , Nikolaev A N 
Published: February 2021

Abstract
Packing for water cooling at counterflow motion of gas and liquid phases has designed by authors of present paper. Such packing differs from other devices in that it is not needs the additional redistributive devices installation, has an opportunity of arbitrary distribution of liquid in apparatus working area due to using of inclined corrugated contact elements. Assessment calculations for packing operation modes determination which purpose is to minimize of dead spaces volume and to increase a circulating water cooling efficiency are performed in this study.
About an algorithm for modeling the isoprene polymerization process in the cascade of reactors using the Monte Carlo method
Authors: Mikhailova T A , Miftakhov E N , Mikhailov V A , Mustafina S I 
Published: February 2021

Abstract
The article describes an algorithm for modeling the isoprene polymerization process based on the Monte Carlo method. The algorithm can be used to simulate polymerization processes carried out in batch or continuous mode. The possible polycentricity of the catalyst used is also taken into account. The model is based on this algorithm makes it possible to study the properties of the polymerization product and calculate the molecular weight distribution for different points in time.
Modelling of ceramic coatings grow during Arc-PVD deposition
Authors: Chernogor A V , Blinkov I V , Volkhonskiy A O 
Published: February 2021

Abstract
This paper presents the results of modeling the growth of ceramic coatings obtained by the kinetic Monte Carlo method. In the considered model, the possibility of forming misoriented grains in the direction of coating growth and in the plane of coating is realized. To verify the model, three coatings of different compositions were prepared, and their structure and composition was studied by TEM and EDS.
Performance computing of an open cycle micro gas turbine powerplant using data aided modeling and simulation
Authors: Thomas Jayachandran A V , Tkachenko A Y , Omar H H , Krishnakumar A 
Published: February 2021

Abstract
In this paper the study of the thermodynamic performance for a 6kW micro gas turbine power plant has been optimized by considering Air-fuel ratio at various altitudes along with fuel inlet temperature. The parametric analysis was performed to improve the overall efficiency of the power plant to obtain the required power needed by a multi-copter. The research deals with parametric optimization for determining realistic and practical combinations for improving the specific fuel consumption and overall efficiency of the Micro gas turbine power plant. The use of recuperators has not been beneficial for the micro gas turbine power system due to the increase in the total volume and weight of the engine. The fuel inventory should be decreased significantly to justify the addition of a recuperator system. The addition of heat exchangers improves the Specific fuel consumption that results in environmental friendly micro gas turbine engines. The result of this work helps to develop and design the micro gas turbine with high efficiency and at the optimized output. A model for a 6 kW micro gas turbine power plant was optimized for the application of primary power units for multi-copter or drones at low altitude conditions. To validate the model, JET CAT PHT3 shaft turbine design parameters were used and the results are compared with the experimental tests on this engine.
Modeling and parametric optimization for a solar-powered closed-cycle micro gas turbine for space applications
Authors: Thomas Jayachandran A V , Tkachenko A Y , Omar H H , Krishnakumar A 
Published: February 2021

Abstract
The research describes the theory design and the modeling of a closed cycle micro gas turbine power plant (CMGTP). A computer simulation model in ASTRA is used to model specifically for this cycle. The software model has been tested for various configurations of gas turbines. For the commercial viability and success of the CMGTP, it should have significant operational feasibility. The working fluid properties play a vital role. The research is a feasibility study to examine the technology for Brayton-cycle based solar thermal power plants and to optimize the model in comparison with Solar array photovoltaic cells to increase the power density by increasing the power generated per unit solar-collector area. A mathematical model for CMGTP was de-signed to power satellites in space environments. The goal is to provide electricity from a parabolic mirror acting as a heat source that is collected by pointing at the sun. The Closed Brayton Cycle power was simulated to produce an output of 6 kW at the generator terminal. The heat source generated from the sun was considered to be around 750 K to 1250 K. The vacuum at the space radiation environment was considered to be 200 K acting as a coolant sink. The optimization of the power plant priorities is followed as High thermal-to-electric efficiency, Low mass, and volume. Computer simulation for thermodynamic analysis was performed on the selection of the working fluids, Brayton cycle design parameters, a heat exchanger (heating and cooling temperatures) that meets the best criteria. A system-level tradeoff study was performed to optimize for achieving target functions for critical factors. The CMGTP consists of a centrifugal compressor, a radial in-flow turbine on a single shaft powering a two-pole permanent magnet alternator.
Nonlinear dynamics of rectangular nano-shells
Authors: Krysko V A 
Published: February 2021

Abstract
Mathematical model of non-linear vibrations of shallow, elastic, isotropic nano-shells with rectangular base subjected to transverse sign-variable load are constructed. Based on Kirchhoff-Love thin shell theory with von Kármán nonlinear strains and the modified couple stress theory (MCST), size-dependent governing equations and corresponding boundary conditions are established through Hamilton’s principle. The governing PDEs are reduced to ODEs by the second-order Finite Difference Method (FDM). The obtained system of equations is solved by Runge–Kutta methods of second order accuracy. The Cauchy problem is solved by the Runge–Kutta fourth-order method. We analyzed the convergence of these solutions depending on the step of integration over time and spatial coordinate. It was revealed, that taking into account nano-effects increases area of harmonic vibrations and leads to the appearance of as chaotic and hyperchaotic vibrations. The carried out numerical experiment shows, that the transition of vibrations from harmonic to chaotic follows to Feigenbaum’s scenario. In particular, to analyze the character type of vibration computation of largest Lyapunov exponents are employed. We found that hyperchaotic vibrations are characterized by two positive Lyapunov exponents and chaotic vibration by one positive Lyapunov exponent. For nano-shells, this phenomenon was discovered for the first time. Lyapunov exponents spectra estimated by different algorithms, including Wolf’s, Rosenstein’s, Kantz’s, and Sawada. Numerical examples of the theoretical investigations are given.
Numerical simulation of bottom topography transformation taking into account the coastal shore protection structures
Authors: Sukhinov A I , Protsenko E A , Sidoryakina V V , Protsenko S V 
Published: February 2021

Abstract
The article presents the results of studies and modeling the dynamics of nonlinear processes of sediment transport and the diagnostics of changes in shallow water relief, taking into account underwater structures that are widely used for coastal protection. The study of these processes was carried out on the basis of 2D model of sediment transport and 3D model of wave hydrodynamics, taking into account the geometry of the bottom topography and the function of elevating the level of the aquatic environment. A discrete model of sediment transport is obtained by approximating the corresponding linearized continuous model. Particular attention is paid to the creation of effective software for conducting hydrodynamic computational experiments. The developed software package allows predicting the dynamics of bottom surface behavior, the appearance of marine braids and ridges, their growth and transformation.