bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Grounded Substrate Effects on Cold Atmospheric Plasma Jet Irradiation of Cellular and Animal models
Authors: Schweigert I. , Alexandrov A. , Zakrevsky D. , Gugin P. , Milakhina E. , Golubitskaya E. , Troitskaya O. , Biryukov M. , Koval O. 
Published: January 2021

Abstract
Plasma devices with cylindrical and plane geometries generating the nonthermal atmospheric plasma jets are used for the treatment of the cancer cells in vitro and in vivo. It is shown in the simulations and experiment that the grounded substrate placed under the bio target essentially increases the plasma treatment efficiency. Nevertheless the temperature control is needed to avoid the burns in a spot of contact of plasma jet with the mice skin. The measured and calculated local temperature increase with different regimes of plasma device operation is presented. The MTT and iCELLigence assays of the viability of cancer cells in vitro show the efficiency of plasma jet treatment and mice models in vivo demonstrate the safety regime for cold atmospheric pressure plasma irradiation.
Current-voltage characteristics of a discharge in a supersonic flow of ionized air in permanent magnets field
Authors: Baranov D.S. , Bityurin V.A. , Bocharov A.N. , Bychkov S.S. , Grushin V.A. , Kusmartseva E. V. , Tretyakova N.V. , Batura N.I. , Zhurkin N.G. 
Published: January 2021

Abstract
The work is devoted to the development of direct conversion devices of energy of high-enthalpy hypersonic gas flow into electrical energy. The experiments were carried out to study the electrical characteristics of the gap between two electrodes filled with weakly ionized plasma of the airflow at the wind tunnel with a magnetogasdynamic accelerator SMGDU. The voltages induced in the field of permanent magnets and the corresponding induction currents were measured with an ohmic load in the external circuit. The current-voltage characteristics of the discharge are constructed for the case of an additional supply of a current pulse from an external source to the interelectrode gap. The conductivity of the medium in the gas flow and the MHD interaction parameter were estimated. The results obtained can be used in the design of surface MHD generators for the autonomous production of electrical power on board of a hypersonic aircraft.
Selectivity of plasma actuators in a boundary layer transition control applications
Authors: Moralev I. , Popov I. , Selivonin I. , Ustinov M. 
Published: January 2021

Abstract
The paper describes the results of the study of broadband velocity pulsations, induced by dielectric barrier discharge plasma actuator in the 2D subsonic boundary layer, and their role in a boundary layer excitation. The origin of the velocity pulsations is the stochastic dynamics of microdischarges. The presented data include the parametric study of the disturbances power on the supply voltage characteristics and their structure. Also, the preliminary study of the role of the broadband disturbances in the Tollmien-Schlichting wave excitation was performed.
CFD analysis of pylon equipped by plasma module for combustion in supersonic airflow
Authors: Firsov A A , Dolgov E V , Kolosov N S , Yarantsev D A 
Published: January 2021

Abstract
Two new geometrical configurations of pylon equipped by plasma module for combustion in supersonic airflow were developed and discussed. This paper presents the results of three-dimensional CFD simulation of the flow around the pylon. The simulation was performed for two modifications of pylon and two possible geometries of set of three pylons. No fundamental difference was found between the two pylon geometries. It was shown that in one case of the installation of three pylons it provides continuous flow around the pylons, which should ensure stable operation of the plasma generator. In the second case of the arrangement of the pylons, the obtained flow structure promotes faster mixing of fuel with air; however, a significant separation zone is formed behind the pylons, which may impede the stable operation of the discharge.
Parameters of an electric discharge in a mixing layer of a supersonic air flow and an injected gas
Authors: Firsov A.A. , Efimov A.V. , Kolosov N.S. , Leonov S.B. 
Published: January 2021

Abstract
The data obtained by spectral measurements, high-speed video recording and the current-voltage characteristics acquisition allowed to estimate the parameters (Te, ne, σ) of the gas discharge plasma organized in a shear layer formed at injection of carbon-containing gases into supersonic air flow. Injection of ethylene (C2H4) into air imitates hydrocarbon fuel; injection of carbon dioxide (CO2) into the air imitates products of chemical reactions.
Acoustic radiation by a Hill vortex in viscous heat-conducting gas
Authors: Cherkasov D.Y. , Shugaev F.V. 
Published: January 2021

Abstract
Acoustic radiation by a Hill vortex has been studied on the basis of the Navier – Stokes equations. We used the expansion of unknown functions into power series of the initial vorticity which was assumed to be small. The Navier-Stokes equations were reduced to a parabolic system with constant coefficients for higher derivatives. The problem is set in such a manner. The vorticity is defined inside a sphere at t = 0. The initial density and the temperature are assumed to be constant throughout the whole space. The solution is represented as a power series whose coefficients are multiple integrals. They have been calculated with the aid of Korobov grids. The density oscillations have been investigated. The frequency spectra were studied at various distances from the vortex. The results may be useful for modelling decaying grid turbulence.
Hydrodynamic phenomena in optical discharges in liquids under self-focusing of periodic-pulse laser radiation
Authors: Lavrentyev S Yu , Solovyov N G , Shemyakin A N , Yakimov M Yu 
Published: January 2021

Abstract
Quasi-stationary flows under the effect of focused periodic pulse femtosecond laser radiation were generated and observed in liquid solvents: water, heavy water, alcohols, ketones, chloromethanes. The mechanism inducing directional flows appears to be directional collapse of the gas bubbles produced by multiphoton dissociation in a focused laser beam. Laser pulses of 450 fs length, up to 220 μJ pulse energy at repetition rates up to 10 kHz have induced stationary flows of liquid originated from the laser beam waist directed along or transversely to the beam axis. The streams along the beam axis were observed under low pulse power (10-20 μJ), provided precise lens adjustment. Lens displacement transversely to the beam axis led to splitting beam waist in two astigmatic foci. Both foci generate the streams along the beam axis. Counter directed streams have collided in the gap between foci, forming the flow spreading transversely to the laser beam. The increase of the pulse energy was followed by formation of the filament of self-focusing. Repeating cycles of focusing and defocusing along the filament produced several beam energy dissipation zones, each one generating separate streams along the beam axis. Colliding of the counter directed streams gave rise to complex flow pattern transversely and upward with respect to the beam axis.
Dielectric barrier discharge in radially converging gas flow generating two coaxial and opposite directed non-thermal plasma jets
Authors: Akishev Yu.S. , Petryakov A.V. , Trushkin N.I. 
Published: January 2021

Abstract
An original source of non-equilibrium low-temperature plasma jets based on a barrier discharge in a radially converging flow of atomic and molecular gases at atmospheric pressure was developed and created. The discharge electrode system consists of two parallel and coaxial quartz disks, in the geometric center of those two coaxial identical holes were made. On the outer side of each disk a metal foil in the form of a wide ring is glued coaxially to the holes. The gas flow is directed from the periphery of the disks to their center and exits normally to the disks surfaces through narrow holes. As a result, two coaxial and opposite directed plasma jets are formed, which are perpendicular to the disks. There are no analogs of the developed source in literature. The source has been tested for plasma treatment of dielectric yarns that are transported through holes in dielectric barriers and are constantly enveloped in plasma jets. The results show practical possibility of using the developed gas-discharge source for continuous “roll-to-roll” plasma treatment of polymer filaments with the aim to improve their hydrophilicity.
Study of the dependence of the structure and luminescence of the discharge channel in a discharge with a liquid cathode from the electrochemical properties of a liquid cathode
Authors: Chistolinov A.V. , Yakushin R.V. , Perfilieva A.V. , Sargsyan M.A. , Gadzhiev M.Kh. , Tyuftyaev A.S. 
Published: January 2021

Abstract
In the present work, the structure of the discharge channels glow of a discharge with a liquid cathode at different pH values of the solution at a given concentration of alkali metal (Na) ions in the solution is investigated by the methods of emission spectroscopy and high-speed photography. The dependence of the atomic sodium line intensity in the emission spectrum of the discharge plasma from the pH value of the solution is investigated. The dependence of the discharge channels filaments shape on the presence of sodium impurities in them is found. The spatial and temporal inhomogeneity of sodium luminescence in the emission spectrum of the discharge channel of a discharge with a liquid cathode at different pH values of the solution is studied. Its connection to the mechanism of sodium transfer into the gas phase is discussed.
Laser breakdown model in the absorption mode behind a light supported detonation wave
Authors: Kiseleva T.A. , Korotaeva T.A. , Yadrenkin M.A. , Yakovlev V.I. 
Published: January 2021

Abstract
The light supported detonation wave (LSDW) propagation with the laser radiation absorption in a narrow layer behind wave’s front is considered in the paper alternatively to the volumetric energy source model usually used for the energy deposition simulation [1-7]. The next laser plasma flow features were revealed in [8] by methods of numerical simulation:
1) laser plasma forms high-speed jet flow behind the LSDW front along the light beam propagation direction,
2) jet parameters are close to an isentropic flow mode at significant distances from the LSDW front, therefor can be determined with a good approximation using the unsteady pressure solution for the point explosion model with a kinematic x-t transformation. These features allow one to determine the plasma momentum value (in the direction of a laser beam) of the optical breakdown as an additional factor of effect on gas flow, first indicated in [9]. For an argon flow, we used a comparative analysis of the results of numerical simulations obtained both accounting the absorbed energy only and the breakdown plasma momentum additionally acquired at the absorption of radiation behind the LSDW front.
The experimental results of an optical discharge plasma in a subsonic argon flow are also presented. Pulse-periodic radiation with a frequency of 40 kHz and average power of 1.6 kW (peak power more than 30 kW) was generated by CO2-laser created in ITAM SB RAS. In order to obtain the LSDW mode by increasing a length of the breakdown plasma a focusing system f / d ≈ 9 was applied. A high-speed video camera with the exposure time of 1.0 μs, and the shooting speed of 200,000 frames / sec was used to record process. It has been established that the plasma dynamics has two successive stages: from the initial high-speed (of the order of 1 μs) propagation of the optical discharge to the subsequent lower-velocity gas-dynamic stage.
On the classification of the laminar-turbulent transition process using the methods of nonlinear dynamics: general analysis and the future
Authors: Evstigneev N M 
Published: January 2021

Abstract
The definition of a turbulent flow is still not mathematically defined. Different methods exists that provide different definitions resulting in different approaches and classifications of the laminar-turbulent transition as well as the fully developed turbulent flows. The paper includes the analysis of different stages of turbulence development, specific methods that are used in each stage and possible methods of unification of these methods based on the nonlinear-dynamical approach. Results are demonstrated for some characteristic fluid dynamics problems. Future highlights on the path to possible unification are discussed.
Fully implicit multiple graphics processing units’ schemes for hypersonic flows with lower upper symmetric Gauss-Seidel preconditioner on unstructured non-orthogonal grids
Authors: Bocharov A N , Evstigneev N M , Ryabkov O I 
Published: January 2021

Abstract
The paper discusses the simulation of the hypersonic flow problems on unstructured grids using fully implicit scheme and the analysis of the orthogonal corrections on the quality of heat fluxes on the surfaces of the bodies subject to hypersonic flow. The governing equations are the Navier-Stokes equations for viscous calorically perfect gas. Second order finite volume discretization is applied to the problem on arbitrary unstructured grids with implicit temporal treatment. The problem is solved using the Newton-Raphson method. Such methods require the solution of large linear systems with iterative solvers and require a preconditioning operator to converge. In this paper a well known Lower-Upper Symmetric Gauss Seidel (LU-SGS) preconditioner is applied. The new method is based on the tricky reordering for the factored Jacobi matrix that allows one to execute block triangular matrix solvers on GPUs in parallel without the loss of algebraic properties of the original non-factored operator. Good convergence properties are demonstrated for large scale problems of external aerodynamics with implicit Courant number around 1000 - 10000 for flows with Mach number around 13-25. The influence of the non-orthogonal corretions on the fluxes for highly scewed anisotropic grids is demonstrated at Mach numbers around 20. It is shown that the non-orthogonality corrections are of the second infinitesimal order compared to the effects of the shock fix influence on the heat fluxes on the body.
Non-stationary layered vector fields and their divergence functions
Authors: Burakhanov B M 
Published: January 2021

Abstract
This paper discusses the general properties of non-stationary layered vector fields and their functions of divergence. According to the classification of vector fields proposed in [1], layered vector fields are vortex vector fields that require two scalar functions to be defined. The main attention is paid to the study of a class of non-stationary layered vector fields that have the property of convergence to a stationary layered vector field. This means that these stationary layered vector fields can be considered as the result of the convergence process of non-stationary layered vector fields. It is shown that the condition for convergence of some non-stationary layered vector fields to a stationary layered vector field is that one of the two scalar functions that must be set to define a layered vector field belongs to the set of so–called scalar T-functions. T–functions are divided into two classes and the general properties of T–functions belonging to each of these classes are considered. Scalar characteristics of the mentioned non-stationary layered vector fields with properties of the Lyapunov function [2] are established.
Near-surface layer formation in the surface dielectric barrier discharge driven by negative voltage pulse
Authors: Soloviev V R 
Published: January 2021

Abstract
The reason of the near-surface layer formation in the Surface Dielectric Barrier Discharge driven by negative voltage pulse has been analysed numerically. According to calculations, the thickness of this layer is around 4μm in atmospheric pressure air; it is inversely proportional to gas density and does not depend on applied voltage value and dielectric parameters. The electric field value inside a layer depends on applied voltage and changes from 60 to 600kV/cm for negative voltage pulse amplitudes from 4.5 to 24kV.
The effect of the exposed electrode oxidation on the filamentation thresholds of a nanosecond DBD
Authors: Selivonin I. , Ding C. , Starikovskaia S. , Moralev I. 
Published: January 2021

Abstract
The paper presents the results of a study of the effect of an oxide film formed on the edge of an electrode on the filamentation threshold voltage of a surface nanosecond DBD. Since the oxidation of the discharge edge has a significant effect on the discharge operation mode and dissipated power, some changes in the filamentation thresholds should be observed. The presented data include the filamentation thresholds of a discharge on an aluminum electrode in synthetic air in the pressure range of 1-10 bar in the case of a new electrode and an electrode covered by an oxide layer. The studies were carried out for both positive and negative polarity of the supply voltage pulse at two pulse shapes with different voltage growth rates. The effect of pulse shape, as well as the effect of air humidity on the filamentation threshold, is discussed.
Emission spectrum analysis of an atmospheric electrode microwave discharge in argon flow and of a cold plasma jet on its base
Authors: Antipov S.N. , Sargsyan M.A. , Gadzhiev M.Kh. 
Published: January 2021

Abstract
The measurements and analysis of the emission spectra both of atmospheric-pressure electrode microwave discharge in argon flow and cold plasma jet induced by the discharge are conducted. We used experimental setup based on the previously developed multipurpose 2.45-Hz-plasmatron with the external portable discharge chamber (plasma torch) with the outlet of 2.5 cm in diameter and power of about several hundred watts. Discharge chamber has 6 rod-like electrodes which form a regular hexagon in a cross section of the torch. Discharge channels are formed between the ends of the electrodes and the inner wall of the chamber. Molecular bands of NO, OH, N2, NH and atomic lines of Ar were found in the spectrum of the discharge channels. Based on the analysis of the spectra, it was shown that the gas temperature in the discharge channel was about 1200 K. In the cold plasma jet spectrum, due to its weak luminescence, only the molecular lines OH and N2 were reliably observed.
MHD simulation of sawtooth events in meridional plane driven by various solar wind velocities
Authors: Gubanov E. V. , Likhachev A.P. , Medin S.A. 
Published: January 2021

Abstract
The meridional global MHD modeling of magnetosphere sawtooth events is performed for three values of the solar wind velocity: 200 km/s, 400 km/s and 800 km/s. The tooth cycle period of the open magnetic field specific flux decreases from 6.4 to 2.0 ks, respectively, while the oscillations amplitude changes inessentially. The tail magnetic field topology evolve through all the standard phases and events. In the distant tail the flapping current sheet is disturbed by the Alfven waves. In the dipole magnetic field domain the night-side attached vortices splitting and their subsequent shedding occur forming the Karman like vortex street. The vortex shedding period falls from 200 s to 110 s with the increase of the solar wind velocity. In the day-side shocked layer the vertically elongated thin magnetic island with the two neutral points is located. The magnetic island accounts for the deflection of the solar plasma inflow around the magnetosphere.
Study of cooling process of plasma jet flowing around a thin ablating graphite rod
Authors: Khromov M.A. , Kavyrshin D.I. , Chinnov V.F. , Sargsyan M.A. 
Published: January 2021

Abstract
We present results of spectroscopic measurement of electron temperature in submerged nitrogen and argon mixture plasma jet for cases of free flow and introduction of thin graphite rod into the jet. The observed cooling of plasma caused by rod introduction agrees with the calculated enthalpy decrease from graphite rod heating and ablation. In this experiment, a marker was used to create artificial optical inhomogeneities in the flow, which allowed us to determine flow velocity from the analysis of their movement. In this case, we aim to determine the degree of influence of rod introduction into the plasma on its parameters. Upon introduction into the plasma, the rod was heated and partially destroyed by the plasma flow, reducing its temperature by 8-20% depending on the flow rate of the plasma-forming gas. The observed plasma cooling was compared with the calculated decrease in enthalpy caused by the cost of heating and ablation of the rod material.
Investigation of LCAO approximation for diatomic molecules in Hartree-Fock method
Authors: Mitin A. V. , Bityurin V. A. , Bocharov A. N. 
Published: January 2021

Abstract
It was shown that the use of the conventional two-center LCAO approximation in the Hartree-Fock method results in non-equivalent description of the asymptotic properties of the total molecular wave function and MO’s in the directions of the united and separated atoms. This leads to a deviation of the Hartree-Fock potential curve calculated with using this approximation from that one obtained without it and which is growing with decreasing the internuclear separation. Additionally, the method has been developed for an investigation of the quality of the asymptotic behavior of the potential curves by analyzing their analytical properties. The direct comparison of the Hartree-Fock potential curves of CH and OH molecules obtained with and without LCAO approximation, as well an application of the proposed method for investigation of the analytical properties of them, display this shortcoming of the conventional two-center LCAO approximation.
Neutron Flux and Soft X-Radiation Created by Heterogeneous Plasmoid
Authors: Klimov A I , Belov N K , Tolkunov B N 
Published: January 2021

Abstract
Experimental results on registration of different radiations from a heterogeneous plasmoid (HP) created by pulsed-repetitive discharge in the experimental set up PVR are considered in this work. Intensive cold neutron flux, optical radiation and soft X-radiation (E<10 KeV) were measured in the HP. It was revealed that there is a high voltage threshold Ud>3.8 kV in the electric discharge for stable generation of intensive cold neutron flux.
Effect of pyrolysis temperature on the synthesis of high-quality MWCNTs by CVD method
Authors: Abdel Aziz Omar , Wafy Tamer Z. , Abdelhafiz Mahmoud , Elsayed Mohamed A. 
Published: January 2021

Abstract
Production of high-quality Multi-Walled Carbon Nano-Tubes (MWCNTs) is essential in some field, especially in medical and mechanical applications. This work illustrates the synthesis of high-quality (MWCNTs) by Injection Chemical Vapor Deposition (Inj-CVD) method using Ferrocene / Toluene solution as a carbon precursor and a catalyst. The effect of synthesis pyrolysis temperature, which has a pivot impact on the synthesis process, was investigated. The structure defects, impurities, thermal stability and sample morphology, as well as the mean diameters of the MWCNTs, were analyzed using Raman spectroscopy, thermal gravimetric analysis (TGA) and scanning electron microscope (SEM), respectively. The results revealed that a change in quality, mean diameter and purity were observed when the pyrolysis temperature varied between 700°C to 850°C. High-quality MWCNTs were observed by Raman spectroscopy at a pyrolysis temperature of 700°C with ID/IG = 0.2. While the outer and inner diameters were 25±6 nm and 7.8±1.5nm respectively, measured by Transmission Electron Microscope (TEM). The Inj-CVD shows an excellent control of the quality of the prepared MWCNTs by optimizing the synthesis temperature.