bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron beam generation with variable current amplitude during its pulse in a source with a grid plasma cathode
Authors: Vorobyov M S , Koval N N , Moskvin P V , Teresov A D , Doroshkevich S Yu , Yakovlev V V , Shin V I 
Published: November 2019

Abstract
In electron sources with grid plasma cathodes, the boundary of the emission plasma is stabilized by a fine-structured grid, the cell size of which is comparable to the size of the Langmuir layer. The correct choice of the cell size of the emission grid allows to stabilize of the emission plasma boundary, reaching a wide range of the parameters adjustment of the generated electron beam with a weak dependence of these parameters on each other. Since the beam current amplitude is most often controlled by a proportional change of the discharge current in the plasma cathode, which allows to change the emission plasma concentration, this paper is investigated the possibility of generating the electron beam having variable amplitude by predicting the change in the discharge current amplitude during its pulse. The described advantage of plasma cathodes makes it possible to obtain electron beams with both a falling and a rising current amplitude of the beam during its pulse. The obtained regimes of electron beam generation open up new possibilities for using this source for both scientific and technological purposes.
Influence of the hole diameter in the perforated electrode on the parameters of electron beam generated by a forevacuum plasma electron source
Authors: Zenin A A , Bakeev I Yu , Klimov A S 
Published: November 2019

Abstract
We present experimental results on geometry optimization of the emission electrode in a plasma cathode electron source operating in the forevacuum range of pressure. For the 2-mm thick emission electrode, we have determined an optimal diameter of the emission aperture that provides the most efficient electron extraction from a hollow cathode glow discharge plasma in helium. At the working pressure of helium in the vacuum chamber 30 Pa, the beam power during emission from a single aperture can vary from 2 to 6 kW, while the beam diameter does not exceed 0.5 mm.
Effect of low-temperature ion nitriding on microhardness, roughness and residual stresses in the surface layer of Ti-6Al-4V
Authors: Agzamov R D , Tagirov A F , Nikolaev A A , Ramazanov K N 
Published: November 2019

Abstract
The paper presents the results of two experimental series with low-temperature nitriding of VT6 titanium alloy in a non-self-maintained high-current arc discharge and in a glow discharge in different regimes. It is shown that microhardness and depth of a surface layer are significantly impacted by the temperature of treatment. The value of surface roughness of the samples is also affected, with a temperature rise from 450 to 600°C resulting in a surface roughness increase by 2–2.5 times. The temperature of nitriding affects the sign and magnitude of residual stresses in a surface layer.
Optimization of the numerical model of the triggerable LTD spark gap switch
Authors: Alexeenko V M , Kondratiev S S , Sinebryukhov V A , Volkov S N 
Published: November 2019

Abstract
In LTD generators, one of the main parts of the primary discharge circuit is the triggerable spark gap switch. For the cavities with oil insulation, the OrCAD switch model was developed [1–3] by taken into account the effect of the trigger pulse on the triggering time of these switches and its spread. According to the real design, the switch in this model is simulated as a block consisting of six independent spark gaps connected in series. However, because of such detailed description of the switch structure this initial model is quite complex causing significant complications in simulation of the full generator in case it includes numerous switches. To avoid that complexity, in the given paper we investigate the possibility to optimize the initial complex model, and present at the output much less complicated switch model with acceptable simulation error.
Production of Al-O-N nanopowders in a plasma reactor with a limited jet flow
Authors: Astashov A G , Samokhin A V , Alekseev N V , Sinayskiy M A , Pakhilo-Daryal I O , Tsvetkov Yu V 
Published: November 2019

Abstract
Experimental studies on the synthesis of aluminum oxynitride nanopowders in a reactor with a confined plasma jet by the interaction of disperse aluminum with ammonia and oxygen in a flow of nitrogen plasma generated in an electric arc plasma torch are performed. Preliminary calculations of the equilibrium compositions and thermodynamic characteristics of the multicomponent Al–O–N system are carried out.
Modeling of the synthesis of ‘core-shell’ composite particles based on segregated oxidation of titanium and silicon tetrachlorides in flow-type plasmachemical reactor
Authors: Aulchenko S M , Kartaev E V 
Published: November 2019

Abstract
The simulation of single-stage synthesis of composite titania-silica nanoparticles in the working zone of flow-type plasmachemical reactor has been performed based on segregated oxidation of titanium and silicon tetrachlorides, with each precursor being preliminarily mixed with air oxygen by means of bubbling. Within the framework of the developed model of the synthesis, the data regarding core size of composite particles, their shell thickness as well as ratio of particles with and without shell have been extracted.
Plasmachemical processing of germanium-containing mineral and technological raw materials
Authors: Batomunkuev D Y , Vashchenko S P 
Published: November 2019

Abstract
This work is a study of the possibility of plasma-chemical enrichment of fly ash. In experiments with a flow reactor, the recovery rate was more more than 99% in slag and 70–80% in unmelted particles. In experiments closed in germanium with the melting of the mineral part of the ash in a reactor with a flowing melt film, an extraction degree of 95–96% was obtained, and the enrichment degree can be estimated as 30–40.
Method for measuring the micro-discharges temperature in the micro-arc oxidation process
Authors: Golubkov P E , Pecherskaya E A , Artamonov D V , Shepeleva J V 
Published: November 2019

Abstract
An automated method for measuring the micro-discharges temperature in the micro-arc oxidation process, allowing measurements to be carried out in real time, is proposed. The design of the measuring transducer, as well as a structural metrological model, taking into account measurement errors is proposed. The possibility of establishing the dependences of the oxide layer micro-hardness on the influencing factors of the micro-arc oxidation process using the Kolmogorov-Johnson-Mehl-Avrami equation by measuring the micro-discharges temperature is shown.
Formed nano-W - WC coatings on the high-speed steel substrate by the electrodischarge explosion
Authors: Grigoryev E G , Smirnov K L , Strizhakov E L , Neskoromniy S V 
Published: November 2019

Abstract
Electric exploding of a tungsten carbide – cobalt material near-by high-speed steel surface forms on it a hardening coating. The essential structure properties of the formed coatings are determined by specifications of contact exploding electrode and the pulse current amplitude and duration. The investigations of coating structures were done by optical and electronic metallography. They have shown that the contact electric exploding caused the transfer of tungsten carbide and cobalt on the surface of high-speed steel. The breakdown of tungsten carbide – cobalt material took place during electrical exploding. The hardening layers of tungsten carbide and pure nanocrystalline tungsten have been formed upon the surface of high-speed steel as a result of electric exploding. Crystalline grains of tungsten have an almost spherical form and their characteristic size less than 400 nm. Micro hardness of the coating layers and high-speed steel structures was measured.
Influence of ion irradiation on the structure and mechanical properties of extruded V95 alloy profiles after artificial aging
Authors: Gushchina N V , Ovchinnikov V V , Makhin’ko F F , Kaigorodova L I , Mozharovsky S M 
Published: November 2019

Abstract
The effect of 10-keV Ar+ ion irradiation on the mechanical properties and structural and phase state of hot-pressed thin profiles 1.5 mm thick and made of an V95 alloy (Al-Zn-Mg-Cu system) after artificial aging (T = 140°C, 16 h) has been studied. Ion beam treatment of the alloy (j = 300 μA·cm−2, F = 1.9·1015 and 1.1·1016 cm−2) without heating the samples to significant temperatures (T < 35–50°C) has not been established to change the ultimate strength and yield strength; however, it increases the relative elongation by 1–2 %. Transmission electron microscopy has shown that irradiation changes the grain structure and the morphology of particles of the crystallization origin in the entire volume of quenched and artificially aged V95 alloy samples (1.5 mm thick). The irradiation does not affect the size and the volume fraction of fine strengthening η′- and η-phase particles.
Effect of irradiation and subsequent aging on the structure of a B-1461 alloy of the Al–Cu–Li–Zn system after megaplastic deformation
Authors: Gushchina N V , Ovchinnikov V V , Makhin’ko F F , Kaigorodova L I , Rasposienko D Yu 
Published: November 2019

Abstract
The effect of Ar+ ion irradiation and subsequent prolonged aging on the microstructure and phase transformations in a B-1461 alloy (Al–Cu–Li–Zn–Mg–Zr–Sc) subjected to megaplastic deformation (MPD) has been studied by transmission electron microscopy. A mixed structure, consisting of nanocrystalline and nanofragmented regions has been found to form in the alloy upon MPD. Subsequent short-term Ar+ ion irradiation (E = 20 keV, j = 300 μA·cm−2, F = 1.9×1015 cm–2) forms dislocation tangles, increases the nonuniform distribution and the size of structural elements, as well as volume fraction of a T2-phase (Al3CuLi5) nano and submicrocrystals heterogeneously nucleated at boundaries. Structural changes are observed at a distance of ~ 200 μm from the surface, which considerably exceeds the projective ion range (~ 20 nm). The structure of the B-1461 alloy after MPD and subsequent irradiation under the above conditions is unstable.
Features of electron-beam processing of metal-ceramic powders in the forevacuum
Authors: Klimov A S , Zenin A A , Tu Tran Van , Bakeev I Yu 
Published: November 2019

Abstract
We present the results of sintering of a metal-ceramic sample consisting of alumina ceramics and titanium. Sintering has been conducted via the surface scanning by the electron beam generated by a plasma electron source. It has been shown that the bake-out temperature affects the formation of the layer with a uniform distribution of elements. We have determined the sintering regimes that enable fabrication of samples with uniformly distributed elements over volume.
Electron-beam plasma and its applications to polymer treatment in the forevacuum
Authors: Klimov A S , Zenin A A , Tu Tran Van , Bakeev I Yu 
Published: November 2019

Abstract
We present our studies of the parameters of helium beam plasma. The beam plasma was generated by a powerful focused electron beam propagating through helium atmosphere at a pressure of 25 Pa. The beam power varied in the range 80 to 1000 W. We have determined the electron beam parameters that enable one to generate a beam plasma with a density greater than 1016 m−3. Using the plasma ions, we have conducted treatment of polymer materials. It has been shown that the beam plasma treatment in the forevacuum range of pressure enhances the hydrophilic properties of fluoroplastic surfaces.
Nanostructuring of the T31507 steel surface by vanadium borides under the influence electron beams in a vacuum
Authors: Milonov A S , Dasheev D E , Smirnyagina N N 
Published: November 2019

Abstract
The microstructures and microhardness of boride layers formed on die steel of T31507 by electron-beam boron reduction in vacuum are investigated and compared. Formed layers have a heterogeneous structure, combining solid and plastic components, leading to a decrease in brittleness of the boride layer.
Influence of nitrogen pressure and electrical parameters of a glow discharge on the process of ion plasma nitriding of steel
Authors: Oskirko V O , Goncharenko I M , Pavlov A P , Zakharov A N , Semenov V A 
Published: November 2019

Abstract
The influence of the working gas pressure on the electrical parameters of the glow discharge and the structure of diffusion hardened layers in the process of ion-plasma nitriding of steel AISI 5140 was investigated. The experiments were carried out in the pressure range of 70–500 Pa, while the power (18 kW), the temperature of the samples (550 °C) and the processing time (6 hours) remained unchanged. The change in gas pressure was accompanied by a change in discharge voltage in the range from 560 to 1800 V and current density from 3.2 to 1.1 mA·cm−2. It is shown that the change in the pressure of nitrogen leads to a change in the energy and density of the particles flows acting on the workpieces. Metallographic and X-ray analysis showed that the surface layers formed at different pressures differ in length, structure, and phase composition. In particular, the maximum width of the diffusion zone of 460 microns was achieved at an operating pressure of 250 Pa The increase and decrease in pressure leads to a decrease in the length of the diffusion zone and an increase in the compound layer to 26 μm.
Phase composition of powder products obtained in direct current atmosphere arc plasma synthesis at the “molybdenum-carbon” system
Authors: Pak A Ya , Yakich Y Tu , Tarasova O V 
Published: November 2019

Abstract
In this paper you can see the results of experimental studies that are devoted to the production of powder. To obtain these materials, an electric arc method without vacuum was used, based on the effect of spontaneous shielding of the reaction zone by gaseous products of combustion of a direct current arc discharge in the gap between graphite electrodes. A feature of the approach used is its implementation without the use of vacuum equipment. The process of electric arc synthesis is implemented in a cylindrical cavity of a graphite cathode, in which a powder mixture of carbon and molybdenum is present. As a result of experiments, multiphase powder products were obtained, which were collected from various parts of the discharge loop electrode system. Three types of products were obtained: collected from the walls of the cylindrical cavity of a graphite cathode, collected from its bottom, and also collected in the form of a cathode deposit. Differences in the phase composition of the products obtained were revealed, and the morphology of micro-sized particles in the synthesis product was determined.
Cascade volumetric acceleration of electrohydrodynamic flows
Authors: Rebrov I E 
Published: November 2019

Abstract
Method of cascade volumetric acceleration of electrohydrodynamic flows at atmospheric pressure air using high-voltage rectangular pulse generator was developed and investigated. The charged particles generated by dielectric barrier or corona discharge and accelerated by synchronizing the ion cloud movement with electric field change of the accelerating electrodes. To implement synchronous switching, a two-channel high-voltage square wave generator was used. It consists of 4 high-voltage switches combined in pairs in a half-bridge circuit and operates at frequency from 100 Hz to 100 kHz and voltage of up to 10 kV. Due to the controlled turning on and off of the switches, the minimum duration of high-voltage pulses is less than 200 ns. The generator is loaded with a two-phase multistage volumetric acceleration system of ion clouds.
Atmospheric pressure diffuse discharge treatment of aqueous solution of methylenum coeruleum
Authors: Ripenko V S , Erofeev M V , Tarasenko V F 
Published: November 2019

Abstract
High voltage atmospheric cold plasma is a novel, non-thermal technology which has shown potential for degradation of various toxic components in wastewater. In this study, the degradation of methylene blue in aqueous solution as a model dye using a cold diffuse plasma source at atmospheric pressure has been investigated. Ambient air used as feed gas and aqueous solutions with same concentrations of the dye were treated by runaway electrons preionized diffuse discharge plasma. The removal efficiency from contaminant increased with the time of treatment increased from 5 to 20 minutes. Optical UV-IR spectroscopy was used for gathering information about the transmittance of aqueous solutions before and after treatment. The experimental results illustrated that transmittance of aqueous solution of methylene blue after 20 minutes of treatment by diffuse discharge plasma increased by ~ 30 %.
Coatings based on chromium carbide fabricated by an arc sputtering of graphite and Cr-Al(Si) targets
Authors: Rubshtein A P , Vladimirov A B , Plotnikov S A 
Published: November 2019

Abstract
Single CrAlC, CrAlSiC and multilayer [CrAlC/a-C]n, [CrAlSiC/a-C]n coatings have been fabricated and investigated. Joint use of arc plasma source with Cr-Al(Si) cathode and pulsed arc plasma source with graphite cathode was applied to single coatings deposition. Diamond-like a-C layers alternate with CrAl(Si)C in multilayer coatings. The doping of CrAlC with silicon is accompanied by an increase in their crystallinity due to the formation of silicon carbide particles. Structural changes make CrAlSiC films harder with a low friction coefficient and a high resistance to plastic deformation. The multilayer coatings are crack resistant.
Chemical transformations initiated by gas discharges in aqueous solutions
Authors: Shutov D A , Sungurova A V , Manukyan A C , Ivanov A N , Rybkin V V 
Published: November 2019

Abstract
The kinetic regularities of the processes of oxidation-reduction of chromium ions under the action of a direct current discharge of atmospheric pressure in air, oxygen and argon on an aqueous solution of potassium dichromate at currents of 20–60 mA and concentrations 0.092–0.4 mmol·l−1 are investigated. The solution served as the cathode of the discharge. It was found that the effect of a discharge in any gas on a solution stimulates the reversible Cr6+↔Cr3+ reactions of oxidation-reduction of chromium ions. The apparent constants of the rates of oxidation and reduction and their dependence on the discharge current and initial concentration are found. The energy efficiency of the process is estimated. It is shown that the discharge in argon is most effective for carrying out the reduction process.
Electroplasma installation for producing high-temperature silicate melts
Authors: Volokitin O G , Shekhovtsov V V , Skripnikova N K , Volokitin G G , Vlasov V A 
Published: November 2019

Abstract
The paper presents the design of an electroplasma installation for producing the high-temperature silicate melts. The optimal operating modes of the screw feeder (from 12.3 kg·h−1 to 25.4 kg·h−1) were established to ensure the production of a homogeneous high-temperature silicate melt. The design of electroplasma installation with a closed volume to produce highly viscous melts with the viscosity values of more than 105 Pa·s is proposed.
Synthesis of Ni-Al intermetallic surface alloys produced by using a low-energy high-current electron beam
Authors: Yakovlev E V , Markov A B , Shepel D A , Solovyov A V , Petrov V I 
Published: November 2019

Abstract
Ni-Al surface alloy electron beam synthesis results are presented. Surface alloy was formed on a carbon steel substrate by multilayer Ni-Al system deposition and subsequent one pulse low-energy high-current electron beam (LEHCEB) treatment in single vacuum cycle. It is shown that surface alloy containing mainly intermetallic phase NiAl is formed as a result of one pulse LEHCEB treatment. It is established that NiAl surface alloy microhardness and wear resistance are higher in comparison to steel substrate parameters.
Coincidence of increasingly volatile winters in China with Arctic sea-ice loss during 1980–2018
Authors: Chen Yang , Liao Zhen , Zhai Panmao 
Published: November 2019

Abstract
Despite intense discussions on the recent boom of mid-latitude wintertime cold extremes, co-variations of warm and cold extremes, i.e. winter temperature volatility, has garnered substantially less attention. Apart from using temperature extremes’ frequency and intensity, we also define ‘temperature whiplash’, which depicts rapid switches between warm and cold extremes, to measure winter temperature volatility in China. Results show that Northeast-, Northwest-, Southwest-, Southeast-China and the Yangtze River Valley have experienced increasingly volatile winters after 1980, co-occurring with precipitous decline in Arctic sea-ice. This enhanced volatility has a strong expression in significant increases in temperature whiplash events, with some hotspots also seeing both warm and cold extremes become more frequent and/or intense. An observation-based detection analysis highlights the dominance of intrinsic atmospheric variability over both anthropogenic warming and sea-ice decline during 1980–2018 in driving winters in China to be more volatile over this period.
Is excess faster than deficient? A molecular-dynamics study of oxygen-interstitial and oxygen-vacancy diffusion in CeO2
Authors: Waldow Stephan P , De Souza Roger A 
Published: November 2019

Abstract
The diffusivity of oxygen interstitials (D
i) and of oxygen vacancies (D
v) in fluorite-structured CeO2 was studied by means of classical molecular dynamic simulation techniques. Simulations were performed on cells that were either oxygen abundant or oxygen deficient at temperatures 1500 ≤ T / K ≤ 2000 for defect site fractions 0.18% ≤ n
i/v ≤ 9.1%. In general, we found that at a given temperature T and defect site fraction n
i/v the vacancy diffusivity D
v was higher than the interstitial diffusivity D
i. Isothermal values of D
i and D
v were constant at low defect site fractions (n
i/v < 0.91%), but the behaviour diverged at higher n
i/v: whereas D
v decreased at higher n
v, D
i increased at higher n
i. The analysis also yielded, as a function of n
i/v, activation enthalpies (ΔH
mig) and entropies (ΔS
mig) of vacancy migration and of interstitial migration. A constant value of

Δ

H

mig
,
v

≈

0.6 eV was found for low n
v, with increases in

Δ

H

mig
,
v

observed for n
v > 0.91%. For low n
i a constant value of

Δ

H

mig
,
i

≈

1.4 eV was found, with a surprising decrease in

Δ

H

mig
,
i

for n
i > 0.91%. The effect of dopants on the behaviour of the defect diffusivities was also studied. Doping with Gd3+ had a detrimental effect on vacancy diffusion, with a slight decrease in D
v and an increase in

Δ

H

mig
,
v

being observed. Donor doping with Nb5+, in contrast, was beneficial, resulting in higher D
i and a decrease in

Δ

H

mig
,
i

. We suggest that the migration mechanism of oxygen interstitials in CeO2, non-collinear interstitialcy, is responsible for the lower defect diffusivity and higher migration barrier.
Measuring Worker Protection Using Leximetrics: Illustrating a New Approach in Four Asia-Pacific Countries
Authors: Mahy Petra , Mitchell Richard , Sutherland Carolyn , Gahan Peter , O’Donnell Anthony , Cooney Sean , Anderson Gordon , Mao Lingfeng , Stewart Andrew 
Published: November 2019

Abstract
This Article introduces the Worker Protection Index (WPI), a new measure for quantitative cross-national comparison of the strength of worker protection provided by law. After presenting an overview and critique of existing labor regulation indices, the Article outlines the conceptual and methodological innovations used in order to develop the WPI. The WPI is wider in scope than many other comparable indices and arguably is more sensitive to variance in labor regulation systems around the world. We then briefly present some initial coding results for Australia, China, Indonesia, and New Zealand, illustrating the impact of our innovations by contrasting these findings with the Cambridge Centre for Business Regulation (CBR) Labour Regulation Index (LRI).