bluuebunny/crossref_metadata_2025_split huggingface dataset:
Politics as construction of the unthinkable
Authors: Laclau Ernesto , Liisberg Marianne , Borriello Arthur , De Cleen Benjamin 
Published: November 2020

Abstract
This article is the English translation of a text originally published by Ernesto Laclau in French in 1981 as part of the
proceedings of the colloquium Materialités Discursives held in Nanterre on 24–26 April 1980. In this text, Ernesto Laclau reflects on the
subject of hegemony as a discursively constructed phenomenon. Building on research on the discursive construction of the acceptability of
popular front politics in 1935 during the Seventh Congress of the Komintern, the author proposes a number of broader arguments on the notion
of antagonism and on some of the problems related to the Marxist conception of totality.
Promoting plurilingual and pluricultural competence in language learning through audiovisual translation
Authors: Baños Rocío , Marzà Anna , Torralba Gloria 
Published: November 2020

AbstractThe effectiveness of audiovisual translation (AVT) for language learning has been widely discussed and demonstrated by scholars in the past (cf.Lertola 2019). Nevertheless, many areas in this field of investigation are still underexplored, such as the usefulness of AVT for the acquisition of plurilingual and pluricultural competence (PPC). This is of paramount importance in the multilingual and multicultural societies we live in, and also given the emphasis the CEFRCompanion Volume(Council of Europe 2018) places on mediation and PPC. The latter has been the focus of the research project PluriTAV (2017–2019), in which the authors of this paper have taken part, aimed at developing a set of activities involving the use of AVT for the acquisition of PPC in the language classroom. This paper sets out to illustrate the theoretical framework sustaining the PluriTAV project and to reflect on the potential of AVT for the acquisition of PPC. This will be achieved by establishing links between AVT modes, transfer/mediation skills, and the descriptors developed within theFramework of Reference for Pluralistic Approaches to Languages and Cultures(FREPA) (Candelier et al. 2012), as well as referring to sample and specific activities developed within PluriTAV. In line with this project, the emphasis will be on language teaching in Higher Education, yet the discussion and the activities suggested could be easily extrapolated and adapted to other educational contexts and levels of language ability.
Who is most affected by the Corona crisis? An analysis of changes in stress and well-being in Switzerland
Authors: Kuhn Ursina , Klaas Hannah S. , Antal Erika , Dasoki Nora , Lebert Florence , Lipps Oliver , Monsch Gian-Andrea , Refle Jan-Erik , Ryser Valérie-Anne , Tillmann Robin , Voorpostel Marieke 
Published: November 2020

ABSTRACT
This study analyses the consequences of the Covid-19 crisis on stress and well-being in Switzerland. In particular, we assess whether vulnerable groups in terms of social isolation, increased workload and limited socioeconomic resources are affected more than others. Using longitudinal data from the Swiss Household Panel, including a specific Covid-19 study, we estimate change score models to predict changes in perceived stress and life satisfaction at the end of the semi-lockdown in comparison to before the crisis. We find no general change in life satisfaction and a small decrease in stress. Yet, in line with our expectations, more vulnerable groups in terms of social isolation (young adults, Covid-19 risk group members, individuals without a partner), workload (women) and socioeconomic resources (unemployed and those who experienced a deteriorating financial situation) reported a decrease in life satisfaction. Stress levels decreased most strongly among high earners, workers on short-time work and the highly educated.
Regularity and uniqueness of Kelvin-Voigt models for nonhomogeneous and incompressible fluids
Authors: Antontsev S N , de Oliveira H B , Khompysh Kh 
Published: November 2020

Abstract
Generalized Kelvin-Voigt equations governing nonhomogeneous and incompressible fluids are considered in this work. In this work, we establish the existence of weak solutions to the considered model. Sufficient conditions ensuring more regular solutions and its uniqueness are also considered.
The research of the dynamics and the form of supercavities during separate and simultaneous motion of strikers under hydroballistic track conditions
Authors: Afanas’eva S A , Burkin V V , Diachkovskiy A S , Ischenko A N , Rogaev K S , Ju Sammel A , Sidorov A D , Chupashev A V 
Published: November 2020

Abstract
The research considers high-speed separate and simultaneous movement of an elongated metal strikers at supercavitation conditions. In the zone around a striker in water the high pressure area appears which makes the adjacent layers of water move. In case of a parallel high-velocity motion of a set of strikers, it is reasonable to assume the availability of the effects caused by their mutual close location.
The load exerted on a rigid wall by a highly porous cylinder during impact
Authors: Belov G V , Markov V A , Popov Yu V , Pusev V I , Selivanov V V , Frolov V V 
Published: November 2020

Abstract
The paper shows the directions to improve the assessment of the external load on a rigid structure during the crash of an aircraft. Our estimates describe the modeling of initial stage of impact (deformation of the nose compartment). The main goal is to evaluate the correctness and applicability of the Riera approach to mechanical equivalent of onboard equipment. Volume-perforated samples of the aluminum alloy D16T were used as mechanical equivalents in numerical and experimental studies. Both our model which uses constitutive equations of high-porous elastoplastic medium (Carroll-Holt model) and direct 3D modeling of the structure of volume-perforated samples by finite element method in the LS-DYNA allows us to obtain the history of load on a rigid wall. We demonstrate the features and differences between this approaches and the Riera approach.
Mathematical problems of calculation and optimization of composite structures
Authors: Golushko Sergey 
Published: November 2020

AbstractMathematical problems of solving direct and inverse problems of mechanics of composite structures are formulated. The problems of strength calculation and optimal design of composite overwrapped pressure vessels are investigated. The solutions of the optimization problem have been recieved and verified by solving the direct problems with obtained design parameters using the classical and improved shell theories. Numerical solutions were obtained using the spline collocation and discrete optimization methods.
Effect of nitrocellulose and 1-methyl-3-nitro-1,2,4-triazole on properties of CuO/Al and Bi2O3/Al nanothermites
Authors: Gordeev V V , Kazutin M V , Kozyrev N V 
Published: November 2020

Abstract
Here we examined how the addition of high-energy materials such as nitrocellulose and 1-methyl-3-nitro-1,2,4-triazole (1Me-3N) would influence the properties of Bi2O3/Al and CuO/Al nanothermite composites. The additives allowed the improvement in explosion force (F) and burning rate (u) of the composites, achieving the maxima at concentrations of 5 % NC and 9 % 1Me-3N for the Bi2O3/Al/1Me-3N mixture, and of 15 % 1Me-3N for CuO/Al/1Me-3N. A further increase in concentrations of the additives decreased the combustion performance of the composites. The effect of the said additives on the properties of nanothermite composites has been considered herein from the standpoint of a simplified model of convective burning in a single pore.
Influence of vibration excitation on the zone of laminar–turbulent transition on a plate
Authors: Grigoryev Y N , Ershov I V 
Published: November 2020

Abstract
Influence of thermal nonequilibrium on the laminar–turbulent transition is studied on the basis of the eN
-method for two widespread flow regimes of a supersonic boundary layer at Mach number M = 4.5. The set of actual frequencies of spatial disturbances was determined from the neutral stability curves for temporal disturbances. The families of N-factor curves were calculated for selected frequencies. The transition Reynolds number was determined for a given transition factor NT
= 8 from the envelopes of the families of N-factor curves. Calculations show that for the level of the vibrational excitation below the dissociation limit and for NT
= 8 the transition zone shifts downstream by 12÷14 % compared to a perfect gas.
The nonlinear relationship between local and macroscopic parameters of dynamic fracture in brittle composite materials
Authors: Grigoriev A S , Shilko E V 
Published: November 2020

Abstract
The paper describes results of a numerical study of the influence of composite structure parameters on the strength and fracture time of brittle materials under dynamic loading. The study is carried out on model concrete samples with different volume fractions of reinforcing inclusions and micropores. Simulation results show that the conventional principle of proportionality of the change in the incubation time of the fracture to the change in the linear dimensions of the fracture region is not applicable when a change in the spatial scale of the region is accompanied by a qualitative change in the parameters of the composite structure. The key factor determining the nonlinear nature of the change in the fracture incubation time during the transition from macroscale to lower scale representative volumes is the factor of phase interfaces, on which primary damage is predominantly localized. This conclusion is confirmed by much more pronounced dependence of the fracture time and dynamic strength of concrete samples on the quantitative concentration of inclusions (i.e. the characteristic distance between zirconia aggregates or micropores) than on volume fraction of inclusions.
Kinematics of the shaped charge jet formation process
Authors: Grif E M , Guskov A V , Milevskii K E 
Published: November 2020

Abstract
Based on the review of scientific and technical literature, an analysis is made of the problems of the modern theory of formation, extension and destruction of the shaped jet. The focus of the research is on the kinematics of the formation of a shaped jet based on the approach of operating with the characteristics of a real metal when the velocity vector of the cumulative jet is the result of three vectors: strain, strain and displacement of the shaped jet’s material. The numerical experiment of the functioning of the shaped charge is carried out, and the procedure for evaluating the calculation results is proposed. The obtained data correlate with existing knowledge about the physics of the cumulation process.
On the effect of plasma electrolytic oxidation on the fatigue strength of V96Ts1 (Al-Zn-Mg-Cu) aluminum alloy
Authors: Zakharchenko K , Kapustin V , Zverkov I , Legan M , Larichkin A , Lukianov Ya 
Published: November 2020

Abstract
One of the tasks of modern material science is to obtain new functional high-strength resistant coatings on structural materials like aluminum alloys. This paper shows the effect of plasma electrolytic oxidation (PEO) on the fatigue strength of V96Ts1 (Al-Zn-Mg-Cu) aluminum alloy. Fatigue tests were carried out with uniaxial loading in accordance with the harmonic law with a constant stress of 205 MPa. The modification of the PEO-coated surface layer led to a 5-fold decrease in the cyclic durability of the V96Ts1 alloy. The dependencies of the temperature of dissipative heating and the accumulated strain on the amplitude of the effective load were obtained for the inelastic cyclic strain of V96Ts alloy samples, with and without a PEO-coated surface layer. These dependencies describing material degradation correlate with the data of the fatigue tests. A fractographic analysis of the destroyed samples was also performed.
On three-dimensional boundary layer stability analysis on curved aerodynamic surfaces
Authors: Kirilovskiy S V , Boiko A V , Poplavskaya T V 
Published: November 2020

Abstract
Numerical simulation of three-dimensional flow past a prolate spheroid located at an angle of attack of 10° accompanied by the laminar-turbulent transition was performed for subsonic (M∞ = 0.136) and transonic (M∞ = 0.75) velocities. The general-purpose gas-dynamic package ANSYS Fluent in integration with a laminar-turbulent transition module based on software bundle LOTRAN 3 was used. The principles of numerical simulation of the main flow are discussed: requirements for the near-wall region allocation and independence of the results from various methods of presetting the position of forced turbulence. It was shown that two instability mechanisms take place in the boundary layer of the spheroid: the Tollmien-Schlichting instability and the cross-flow instability with a predominance of the last on side surfaces. A comparison of predicted position of the transition for different flow regimes was performed.
Investigation of residual stress in composites produced by explosion welding with ultrasound
Authors: Kuz’min E V , Korolev M P , Kuz’min S V , Lysak V I 
Published: November 2020

Abstract
The paper presents the results of experimental studies of residual stress in homogeneous steel samples obtained by explosion welding with simultaneous exposure to ultrasound. For experimental determination of residual stress in composites, a method based on sequential removal of thin metal layers from the sample surface and measurement of deformations of the sample from the opposite side using strain gages was chosen. It is shown that the introduction of ultrasound in the process of explosion welding leads to both a redistribution of residual stress and a significant decrease in their maximum values measured in the immediate vicinity of the junction zone of steel samples.
Comparative testing of MOST and Mac-Cormack numerical schemes to calculate tsunami wave propagation
Authors: Lavrentiev M , Marchuk An , Oblaukhov K , Romanenko A 
Published: November 2020

Abstract
The problem of fast, reliable, and accurate calculation of tsunami wave propagation is addressed. Based on the shallow water approximation, two numerical approaches to calculate tsunami wave propagation are compared at the same computational mesh. To evaluate precision of numerical solutions the available exact solutions (for the cases of sloping and parabolic bottom) are used. Results of several numerical tests are presented. Time required to obtain tsunami wave height maxima distribution is briefly discussed, too.
On the possible of the abnormally high damping effective properties of dispersion-reinforced composites and fibrous composites
Authors: Lurie S 
Published: November 2020

Abstract
We study the effective energy dissipation properties of solid polymer matrixes filled with coated spherical and fibrous inclusions coated with a layer of lossy viscoelastic material. The matrix and the inclusions are assumed to be separated by equal-thickness interfacial layers of a lossy viscoelastic material. We show that the remarkable loss amplification mechanism is operative in such particulate-morphology materials when the effective loss properties of composite can exceed the loss properties of the pure matrix by more than 20 times.
A mathematical model of stationary charging processes in polar dielectrics: theoretical analysis
Authors: Maksimova Nadezhda , Maslovskaya Anna 
Published: November 2020

Abstract
We address some global solvability issues for non-linear stationary convection-reaction-diffusion problems. Global solvability of the boundary value problem for the stationary model of a charging process of polar dielectrics under non-equilibrium external conditions is proved. The maximum principle for volume charge density is established.
On the global unique solvability of a problem for one-dimensional equations of dynamics of mixtures of viscous compressible heat-conducting fluids
Authors: Mamontov A E , Prokudin D A 
Published: November 2020

Abstract
One-dimensional equations of the multi-velocity model of the dynamics of mixtures of viscous compressible heat-conducting fluids and their approximation are considered. The existence and uniqueness of a strong solution to the initial-boundary value problem is proved globally in time.
Spark ignition of a mixture of aluminum and boron powders
Authors: Moiseeva K M , Yu Krainov A 
Published: November 2020

Abstract
The paper presents the results of the numerical solutions of the problem of spark ignition aero suspension mixture of powders of aluminum and boron. The physical and mathematical model of gas suspension combustion is based on the approaches of the mechanics of two-phase reacting media. The solution to the problem is based on the decay algorithm of an arbitrary discontinuity S. K. Godunov. From the solution of the problem, the dependence of the minimum energy of spark ignition on the radius, mass concentration and the fraction of aluminum and boron particles in the gas suspension were determined.
Mathematical model of the flotation complex particle–bubble within the framework of Lagrangian formalism
Authors: Moshkin N P , Kondratiev S A 
Published: November 2020

Abstract
A model of the interaction of a spherical gas bubble and a rigid particle is derived as a coupled system of second-order differential equations using Lagrangian mechanics. The model takes into account oscillations of the bubble surface and the attached to it solid cylindrical particle in infinite volume of ideal incompressible liquid. The capillary force holding the particle on the bubble is due to the shape of the meniscus surface, which determines the wetting edge angle. The series with respect Legendre polynomials is used to present small axisymmetric oscillations of the particle-bubble system. Potential and kinetic energies are expressed through coefficients of this series. Particle adhesion condition to bubble surface is implemented through Lagrange multipliers. The dependence of the particle size and its density is demonstrated as a result of the numerical integration of the resulting dynamic system of differential equations.
Influence of external disturbances on the flow of straight and swept wings
Authors: Pavlenko A M , Bykov A V , Yu Zanin B 
Published: November 2020

Abstract
The paper presents the results of experimental studies of the influence of incoming external disturbances on the flow of straight wing and UAV models at different angles of attack and slip. Using the method of hot-wire anemometry, quantitative data were obtained on the structure of the flow near the surface of the model when it flows around a free stream and in the presence of incident external disturbances. Pictures of the visualization of the flow around models under stall conditionswere obtained. It was found that incident external disturbances under certain conditions can significantly change the flow structure.
Solvability of a model problem sublimation of snow
Authors: Papin A A , Sibin A N 
Published: November 2020

Abstract
The mathematical model water and air movement in snow is studied taking into account sublimation. Snow is simulated as a four-phase continuous porous medium. The pores are entirely occupied by a mixture of water, air and vapor. To describe the process, the mass conservation equations for each phase, the Musket–Leverett system of two-phase filtration equations for water and air, and the energy conservation equation for snow are used.
Point explosion in a bubble media. Research results and the prospects for the application
Authors: Pinaev A V 
Published: November 2020

Abstract
A point explosion (explosion of wires with an electric discharge energy of ≈10÷103 J) in chemically inert and active bubble media was experimentally studied. The advantages of initiating bubble detonation by a point explosion are compared with the traditional method of initiating a plane shock wave. The possibility of detonation transfer during a point explosion in a bubble medium to the volume of an explosive gas above the interface between media is established. The dynamics of spherical shock and detonation waves in bubble media is investigated.
Thermodynamically compatible model for wavefields simulation in deformed porous medium saturated by a compressible viscous fluid
Authors: Romenski E , Reshetova G , Peshkov I 
Published: November 2020

Abstract
A computational model for the small amplitude wave propagation in an elastic porous medium saturated by the viscous compressible fluid is discussed. The presented model is an extension of the model [1] and its derivation is based on the symmetric hyperbolic thermodynamically compatible system for two-phase solid-fluid mixture with finite deformations of the solid phase. In the present consideration, the fluid viscosity is taken into account via the unified hyperbolic model for viscous flows with shear stress relaxation. The governing equations form a hyperbolic system written in terms of the mixture velocity, relative velocity of phase motion, pressure and shear stress of the mixture that allows to apply an efficient finite difference method for numerical solution. Some numerical examples are presented, showing physically correct results, and, in particular, the frequency dependence of the shear wave velocity.
Multiplicative boundary control problems for nonlinear reaction-diffusion-convection model
Authors: Saritskaia Zh , Savinov P 
Published: November 2020

Abstract
Global solvability of a boundary value problem for a generalised Boussinesq model is proved in the case, when reaction coefficient depends nonlinearly on concentration of substance. Solvability of control problem is proved, when the role of controls is played by mass exchange coefficients from the boundary conditions of the model.
Unique solvability of an equilibrium problem for a Kirchhoff-Love plate with a crack along the boundary of a flat rigid inclusion
Authors: Semenova G E , Lazarev N P 
Published: November 2020

Abstract
A new model of an equilibrium problem for a Kirchhoff-Love plate with a flat cylindrical rigid inclusion and an interfacial crack is considered. As in previous works, we consider a rigid inclusion defined with the help of a cylindrical surface, but unlike the known models relating to the crack theory, we suppose that traces of derivatives of vertical displacements (deflections) satisfy certain boundary conditions. These conditions determine constant angles of normal fibers along an entire flat cylindrical inclusion. The interfacial crack is located on the boundary of the rigid inclusion. A condition of mutual non-penetration of opposite crack faces is given as an inequality on the crack curve. We prove the existence and uniqueness of a solution for this variational problem.
Effect of predominantly unidirectional flow of a viscous liquid between solid walls
Authors: Sennitskii V L 
Published: November 2020

Abstract
The problem is considered on a flow of a viscous liquid in the presence of solid bodies – two walls and a free plate the boundary of which is permeable for a liquid – under oscillatory influences. The formulation of the problem includes the equation of the plate motion, the equations of Navier–Stokes and a continuity and conditions at solid boundaries of the liquid. The new hydro-mechanical effect is revealed which consists in that in the absence of a predominant direction in space free parts of the hydro-mechanical system at a background of oscillations perform a unidirectional, steady motion.
Inertial waves generated by circular oscillations of inner core in a rotating spherical cavity
Authors: Subbotin S , Shiryaeva M , Kozlov V 
Published: November 2020

Abstract
The fluid flow excited by a core oscillating in a rotating spherical cavity is experimentally investigated. The core performs circular oscillations around the rotation axis under the action of an external inertial field and generates inertial waves. The main attention is paid to the effect of the oscillation frequency on the instantaneous flow structure and intensity. It is found that at a certain frequency, inertial waves experience spatial resonance, resulting in the intensification of oscillatory flow.