bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guidance on Bayesian uncertainty evaluation for a class of GUM measurement models
Authors: Demeyer S , Fischer N , Elster C 
Published: August 2020

Abstract
In this paper we provide guidance on a Bayesian uncertainty evaluation for a large class of GUM measurement models covering linear and non-linear models. Bayesian analysis takes advantage of useful prior knowledge on the measurand, which is often available from a metrologist’s genuine expertise and opinion, or from previous experiments and which is neither taken into account by the GUM nor by its Supplement 1. For the considered class of measurement models, we establish the equivalence with the related statistical models and derive analytical expressions of the posterior distribution for an appropriate family of prior distributions, which allows one to gain insight into the result of the Bayesian uncertainty evaluation. We extend this work to the formulation of arbitrary prior distributions for the measurand and provide some guidance to set hyperparameter values within a class of priors based on elicitation techniques, so that the resulting priors reflect the prior knowledge. Posterior distributions are calculated by Markov Chain Monte Carlo methods. We apply the Bayesian uncertainty evaluation to the mass calibration example of Supplement 1 and compare our results with those obtained by the GUM and its Supplement 1. In order to study the impact of the choice of method for this example, we carry out a sensitivity analysis of the results with respect to the choice of prior. We show a virtually strong effect of the prior distribution which results in reduced uncertainty estimates for a small number of observations. When using noninformative priors, we obtain results comparable to those achieved by GUM-S1. Python code is made available that enables a Bayesian uncertainty evaluation also in other applications covered by the considered class of GUM measurement models.
Dynamics of interacting bubbles located in the center and vertices of regular polyhedra
Authors: Aganin I A , Davletshin A I 
Published: August 2020

Abstract
The dynamics of spherical gas bubbles located in the center and vertices of regular polyhedra under a sharp pressure increase in liquid is studied. Before the pressure rise, the liquid and the bubbles are at rest, the liquid pressure is 1 bar, the radii of the bubbles are 0.25 mm. The liquid pressure rises by 3 bar. For comparison, the configurations with one bubble in the center of a sphere and the others stochastically distributed inside it are also considered. In all the cases, the initial minimum distance between the centers of the bubbles does not exceed 5 mm. A mathematical model is used, in which the dynamics of the bubbles is governed by second-order ordinary differential equations in the radii of the bubbles and the position-vectors of their centers. It is shown that in all the bubble configurations considered, the amplitude of the pressure oscillations in the central bubble decreases nonmonotonically. With a sufficiently large number of peripheral bubbles, the change in the amplitude begins with a phase of its significant increase. With a rise in the number of the peripheral bubbles, the oscillation frequency of all bubbles decreases.
The influence of the capacitive coupled radio-frequency discharge on flax fiber
Authors: Aazanova A , Abutalipovaand L N , Khisamiyeva LG 
Published: August 2020

Abstract
The article presents the results of a study of the effect of radio-frequency (RF) capacitive plasma discharge at low pressure on flax textile fiber. The study object was a standard bleached and boiled flax yarn. In the considered modes, plasma treatment does not significantly affect the cellulosic component of flax fiber. However, the results of scanning electron microscopy showed signs of etching on the samples of bleached yarn. The results of x-ray diffraction demonstrated slight increase of the proportion of the crystalline phase. This is due to selective etching amorphous sections of the fibers surface. The results of determining the lignin content showed that it is relatively resistant to the action of RF plasma discharge and plays a protective role in relation to cellulose. However, damage (etching) of the fibers surface facilitates the rapid penetration of water into the fiber; therefore, lignin passes from fiber to aqueous solutions faster. The increase of the capillarity by 2–3 times, and the increase of the colourability and the breaking load of flax yarn by 25% are the technological effects of plasma processing of flax fiber (in the considered modes).
Research of the influence of a hydrocarbon coating on the operational stability of membrane fabric
Authors: Vishnevskaya O V , Voznesensky E F , Vishnevsky V V , Shaekhov M F , Nizamova D K , Ahverdiev R F , Tihonova N V , Mahotkina L Y 
Published: August 2020

Abstract
The effect of the hydrocarbon coating on the operational stability of membrane tissues is investigated. Coating on membrane tissues was obtained by plasma-chemical vapor deposition of the products of polymerization and decomposition of acetylene. As a result, the resulting coating allows to: increase resistance to multi-cycle abrasive impact by 9,9-30,1%, while the resistance of the textile base to light, washing, dry and wet friction does not deteriorate; increase tensile strength by 5,7-13,4%; increase elongation to 11,0-18,4%. The stability of fixation of organosilicon impregnation in the structure of the textile base after modification in a nonequilibrium low-temperature plasma increases to 45,5%.
Determination of factors influencing the speed of moving arcs by rectanine electrodes
Authors: Gabdrakhmanov Az T , Israphilov I H , Galiakbarov A T , Gabdrakhmanova T F 
Published: August 2020

Abstract
A mathematical description of the gas motion in an electric discharge moving in the interelectrode gap under the action of the Lorentz force, considers in this paper. The presented model of the electric arc allows one to calculate the magnetic field acting on the charges in the discharge and to explain the occurrence of the arc shunting effect when moving along the electrodes.
Changes in the surface structure of nanostructured ceramics YBa2Cu3O7-y after exposure to a plasma stream
Authors: Gadzhimagomedov S Kh , Palchaev D K , Murlieva J Kh , Gadzhiev M Kh , Ragimkhanov G B , Demirov N A , Emirov R M , Rabadanova A E , Saypulaev P M 
Published: August 2020

Abstract
The paper presents the results of a study of the surface structure of nanostructured superconducting ceramics YBa2Cu3O7-y (YBCO) before and after short-term exposure to a plasma stream. Exposure to the plasma stream changes the structure of the ceramic surface and the oxygen content in it, and also slightly increases the average crystallite size.
High frequency electric discharge between jet and solid electrodes
Authors: Kuputdinova A I , Akhmadullina L I , Zheltukhin V S , Gaysin Al F , Gaysin F M , Gaysin Az F 
Published: August 2020

Abstract
The types and forms of combustion of electric discharges of high-frequency (HF) current with liquid and solid electrodes at atmospheric pressure are investigated. The discharge emission spectrum, plasma composition, electron concentration, and temperature of the heavy component are studied. Thermograms on the surface of liquid and solid electrodes during the combustion of the discharge are investigated.
Electrolyte-plasma product treatment
Authors: Akhmadullina L I , Gaisin Al F , Gaisin Az F , Kashapov N F , Zheltukhin V S 
Published: August 2020

Abstract
The low-temperature plasma of direct current electric discharges in the process of surface treatment of a product investigated. The types and forms of discharge burning investigated. The electric parameters of the discharge, oscillations of the current and voltage of the discharge, the power invested in the discharge investigated. The temperature distributions of the electrodes in the combustion zone of the discharge investigated. The composition of the discharge plasma, the electron concentration, and the rotational and vibrational temperatures of the heavy components are studied. The micro relief of the surface of the product studied before and after electrolyte-plasma treatment.
Features of formation of fullerene-containing soot during combustion gaseous and liquid hydrocarbons
Authors: Shakirov A S , Galeev I G , Ya Asadullin T 
Published: August 2020

Abstract
Features of obtaining fullerene-containing soot during combustion of gaseous and liquid hydrocarbons with the influence of an electric field on the flame are discussed. The characteristic voltage - current characteristics of the discharge created in the flame region and electron microscopic photographs of fullerene-containing soot were obtained.
Modification of semi-finished rabbit pelts by low-temperature plasma
Authors: Garifullina A R , Sysoev V A , Lutfullina G G , Tihonova V P , Kuznetsova O P , Nasirova R A , Astafeva A E 
Published: August 2020

Abstract
The influence of the effect of plasma processing and non-isocyanate urethanes on the skin of rabbit pelt has been investigated. Synergistic effect of modification resulting in the change of microstructure of high-molecular material and increasing chemical activity of collagen is established. In order to study the regularities of plasma effect on the skin of rabbit pelt the following indicators were determined: heat resistance temperature, relative moisture content (in mass), strength characteristics.
The problem of the structure of quasi-stationary electromagnetic field of an infinite solenoid induction loaded with a metal cylinder of constant conductance
Authors: Gerasimov A , Kirpichnikov A 
Published: August 2020

Abstract
An exact solution of the problem of distribution of the magnetic and electrical field intensities in space around the metal cylinder placed inside an infinite solenoid, with alternating current flowing through it, is obtained. The solution is derived for Maxwell equations, describing the cylindrically symmetric electromagnetic field outside the metal cylinder for complex values of the magnetic and electric components of the electromagnetic field. A comparison between the derived exact solution and an approximate one is drawn. Their asymptotic convergence is shown.
Structural and chemical changes of aramid fibers modified by low temperature plasma
Authors: Ibatullina A , Krasina I , Antonova M , Ilushina S , Isayeva E , Mingaliyev R , Parsanov A 
Published: August 2020

Abstract
The article considers changes in the properties of Rusar-S brand aramid fiber due to the treatment of low-pressure plasma of radiofrequency capacitive discharge. After modification, there was recorded the growth of hydrophilicity in the environment of inert and oxidizing gases. The paper discusses the results of IR spectroscopy of Rusar-S aramid fiber before and after plasma modification. An obtained data of research can explain the influencing mechanisms of RFC discharge plasma of a low-pressure on the properties of aramid fiber.
Effect of the variable gradient of sound speed on pulsating combustion of the solid fuel in Helmholtz resonator-type setup
Authors: Larionov V M , Iovleva O V , Malahov A O , Larionova I V 
Published: August 2020

Abstract
In previous works, a theoretical study of pulsating combustion of solid fuel in Helmholtz-resonator-type setup was carried out under the condition that the distribution of the sound speed in the combustion products is constant, i.e. independent of the amplitude of gas oscillations. In this work, it is assumed that the gradient of sound speed linearly depends on the amplitude of pressure fluctuations in the combustion chamber. It is shown that the frequency of oscillations calculated for variable gradient of the sound speed differs significantly from the frequency that corresponds to a constant gradient.
Distribution of electric potential during pulsating combustion of a propane-butane fuel mixture with air in a vortex combustion chamber
Authors: Malahov A O , Larionov V M , Fadeev S A , Sadikov K G , Khalilov A R 
Published: August 2020

Abstract
Currently, research on pulsating combustion regimes, in particular, control methods, remains relevant. Pulsating combustion mode has its own electric field created due to the ionization of the combustion products and is characterized by oscillatory processes of the combustion zone. In this work is to assess the effect of acoustic gas vibrations on the distribution of electric potential and its amplitude-frequency characteristics.
Pulsating combustion of propane-butane fuel mixture with air in a vortex combustion chamber
Authors: Malahov A O , Larionov V M , Iovleva O V , Gaianova T E , Gaponenko S A 
Published: August 2020

Abstract
In this paper pulsating combustion of a pre-mixed propane-butane fuel with air in a vortex combustion chamber is considered. In view of the insufficiency of information about the reasons of self-oscillations, it is necessary to determine the gas-dynamic, physical and chemical parameters that cause oscillations of the heat release rate in the vortex combustion chambers.
Modification of the surface of polyethylene by low-temperature plasma and liquid electrodes
Authors: Mardanov R R , Kayumov R R , Akhatov M F , Gazizova A I , Gaisin A F 
Published: August 2020

Abstract
In the framework of this work, experimental studies of the modification of the surface of polyethylene by low-temperature plasma and liquid electrodes at atmospheric pressure were carried out. For these purposes, a direct current experimental setup was used. The results of modifications in the parameter range are presented: voltage U = 400 … 800V, current I = 0.3 … 0.8A, jet length l = 50mm, electrolyte flow rate G = 6.2ml / s, jet diameter d = 3mm, NaCl concentration 26%. Estimates of the results are given.
A review of use of barrier discharge for modification of surface of polymers
Authors: Mardanov R R , Kayumov R R , Akhatov M F , Gaisin A F 
Published: August 2020

Abstract
In the framework of this work, a review of the use of a barrier discharge for modifying the surfaces of various polymer products is given. There are various examples of reducing, increasing the wettability angle of modified samples, deforming, smoothing their surface and changing their surface energies.
Study of electric spark coatings of nanocrystal structure
Authors: Sakhapov R L , Makhmutov M M , Sultanov V A 
Published: August 2020

Abstract
The article presents the results of studies of new electrospark coatings having an amorphous and nanocrystalline structure. The results of metallographic and X-ray diffraction studies are analyzed. The microhardness and thickness of the coatings were studied. For the formation of a nanostructure, a plasma spraying method is used, in which materials are formed upon separate solidification of particles, most often disk-shaped. When the thickness of the sprayed particles is up to 10 μm, they quench from the liquid state at a cooling rate of 108 K / s. Nonequilibrium structures in sprayed particles with a nanocrystalline and amorphous structure have high mechanical properties. However, the use of plasma spraying in some cases is not advisable, due to the relatively high cost of equipment and materials. Therefore, this article will present the results of studies on the creation of amorphous and nanocrystalline coatings using electrospark processing (ESP), which is a cheaper way to obtain them.
Nonequilibrium low temperature plasma in process of collagen containing polymer materials electrical properties modification
Authors: Makhotkina L Yu , Bil V , Khristoliubova V I 
Published: August 2020

Abstract
The process of treatment with nonequilibrium low temperature plasma allows to reduce collagen materials electric potential due to charges dissipating along leather surface. Under certain conditions the main reason for the generation and accumulation of static electricity is the high hydrophilicity of the material. Leather surface hydrophobization is achieved through water repellent application and bulk nonequilibrium low temperature plasma treatment. Despite material surface hydrophobization nonequilibrium low temperature plasma processing parameters for genuine collagen containing polymer materials hygroscopicity increasement are determined. Collagen containing polymer materials plasma treatment also increases its biological compatibility and antimicrobial properties, improves mechanical characteristics by changing the internal structure of the material.
Properties of Al2O3 coatings obtained by electric arc plasma method in “dynamic vacuum”
Authors: Mordynsky A V , Gadzhiev M Kh , Tyuftyaev A S , Gusev V M , Borodina T I 
Published: August 2020

Abstract
The results of studies of the influence of the electrophysical characteristics of a heterogeneous plasma flow on the properties of Al2O3 coatings (phase composition, adhesion, porosity) during plasma arc thermal spraying on a steel grade 20 in dynamic vacuum, in the pressure range from 7 to 50 kPa and at 100 kPa are presented. As well as the results for different plasma thermal spraying modes (power, consumption rate of plasma-forming gas and powder, pressure in the chamber). For the plasma torch design in this work, it was shown that Al2O3 particles are deposited most efficiently when their size is up to 100 μm, with an arc current of 300 A, flow rates for powder 0.1 g/s and for plasma-forming gas of up to 1 g/s in the pressure range (2.0-3.0) • 104 Pa.
Viscous fluid flow in a wide annular gap of two rotating coaxial cylinders
Authors: Morenko I V 
Published: August 2020

Abstract
The Couette-Taylor flow is considered in a wide gap between coaxial cylinders in the case when the outer cylinder is at rest and the inner one rotates at a constant speed. Unsteady motion of a viscous fluid is described by the system of Navier-Stokes equations. The problem is solved by the control volume method in the OpenFOAM software. Two stable states were obtained depending on the surface rotation speed: the cylindrical Couette flow and the Taylor vortex flow. The calculation results are compared with the known data of other authors. The dependence of the dimensionless shear rate on the Taylor number is obtained.
Study of the Surface Structure Variations of AK5M7 Alloy after Electro Spark Alloying and Annealing
Authors: Hasan I K , Fomin N E , Kyashkin V M 
Published: August 2020

Abstract
The current work presents the results of studding surface structure of the AK5M7 aluminum alloy hardened by the Electro Spark Alloying (ESA) technique with subsequent annealing. Analysis of crystallite size (CS) values, microdistortion of phase crystal lattices found on the surface, microhardness, and wear resistance allows concluding that, the degree of defectiveness of the surface structure plays a decisive role in its wear resistance.
Full compensation of reactive power in electric networks 0.4-10kV
Authors: Nazarychev S A , Akhmetshin A R , Gaponenko S O 
Published: August 2020

Abstract
The most important task in electric networks is to reduce energy losses. According to Network Company, in distribution electric networks with a voltage of 0.4-10 kV, they account for 62% of the total number of losses. One way to save energy is reactive power compensation. From Order of the Ministry of Energy of the Russian Federation dated June 23, 2015 No. 380 “On the Procedure for Calculation of the Ratio of Consumption of Active and Reactive Power for Individual Energy Receiving Devices (Groups of Energy Receiving Devices) of Electric Power Consumers” at a voltage of 0.4 kV, the reactive power coefficient should not exceed the value 0.35, and on the side of 10 kV - values of 0.4. In practice, in distribution electric networks, reactive power compensation devices are not installed in most cases, and the reactive power factor is 2-3 times higher than the standard values. Since compensating devices are expensive equipment, it is necessary to evaluate the feasibility of deep reactive power compensation, in the range of reactive power factor changes from its standard value to zero. The article discusses the economic and technical feasibility of deep reactive power compensation. The use of a generalized parameter of the electric network for determining the voltage at substations of distribution electric networks is proposed. The need for the coordinated use of reactive power compensation devices and booster transformers to ensure the quality of electricity is shown.
Threshold frequency of standing wave at hydrodynamic separation of particles
Authors: Gubaidullin D A , Osipov P P , Nasyrov R R 
Published: August 2020

Abstract
In this paper, the question of the separation of particles in a standing wave in closed resonator at first resonance frequency is considered. The threshold values of the frequency of the standing wave, as well as the densities and radii of the particle, which allow to separate the particles depending on their radius and density are studied.
To the question about mechanisms for the formation of dust fractal structures from an arc plasma
Authors: Smolanov N A 
Published: August 2020

Abstract
The paper presents the results obtained in the study of dusty particles of an arc discharge plasma (fractal aggregates). One of the possible reasons for the formation of fractal structures is the current layers. These are ion flows between adjacent cathode spots of an arc discharge. The magnetic field of the current sheet is an energy source, the dissipation of which leads to the creation of instability of the growth front. In this area, the formation of fractal-like aggregates (drift-dissipative instability) can occur.
Influence of plasma modification on free surface energy of synthetic fibrous materials
Authors: Timoshina Y A , Voznesensky E F , Karnoukhov A E , Krasina I V , Rakhmatullina G R , Pankova E A , Shagivalieva R R 
Published: August 2020

Abstract
The results of experimental studies of the effect of plasma modification in various plasma-forming gases on the acid-alkaline properties and free surface energy of samples of synthetic fibrous materials are presented. The effect of changes in the free surface energy of fiber samples on their adhesion to an epoxy binder in a composite material is studied.
Numerical simulation of the propagation of a shock wave from a neutral and electrically charged dusty medium into a homogeneous gas
Authors: Tukmakov D A , Tukmakova N A 
Published: August 2020

Abstract
In this work, the expansion of a shock wave from a dusty medium into a pure gas is simulated. The carrier medium is described as a viscous compressible and heat-conducting gas. A mathematical model of the dusty medium dynamics allowed for force interaction. Also, the mathematical model took into account inter-component heat transfer. The aim of the work was to study the effect of the electric charge of the dispersed component on the parameters of a shock wave during the passage of a shock wave from an inhomogeneous medium to a homogeneous gas. Differences between processes in neutral and electrically charged dusty media were revealed.
The Influence of Supersonic Gas Stream on Spatial Structure of Glow Discharge
Authors: Timerkaev B A , Shamsutdinov R S 
Published: August 2020

Abstract
This work investigates into the properties of longitudinal glowing discharge in supersonic gas stream between central body and reducer. It has been established that the properties of discharge spatial localization, intensity of radiation, formation of near-electrode areas directly depend on arrangement of supersonic stream. This work analyzes the properties of gas stream in expanding area of supersonic nozzle, pressure recovery in reducer. It has been experimentally established that gas circulation at supersonic speed in the area of glowing discharge makes it possible to control the distribution of concentration of neutral particles in interelectrode space as well as localization of near-electrode zones and positive glow.