bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the spatio-temporal variability of the Black Sea upper mixed layer thickness based on the results of numerical calculations
Authors: Ratner Yu B , Kholod A L 
Published: November 2019

Abstract
The results of the Black Sea uniform mixed layer (UML) thickness determination were used for investigation of its spatio-temporal variability based on numerical calculations of the monitoring and forecasting center of the Black Sea (BS MFC). The spatial distribution of the mean and standard deviations of the UML depths in the Black Sea has been studied over the seven-year period. The time series analysis of UML thickness was performed by their spatial averaging over the Black Sea area for each day of the seven-year period. The principal components of the variability of the spatio-temporal UML depths field have been studied. The areas of high and low UML depths variability and the frequency-time characteristics of their variations have been determined.
Motion of a single vapor Taylor bubble in the vertical tube of small diameter
Authors: Slesareva E Y , Dekhtyar R A , Ovchinnikov V V 
Published: November 2019

Abstract
An experimental study of the dynamics of the Taylor vapor bubble in water and in an aqueous solution of lithium bromide at vapor saturation pressure was carried out. The Taylor bubble was formed after boiling-up of the overheated degassed liquid in 16 mm diameter tube. The study has shown that the dynamics of the vapor cavity during boiling up leads to a qualitative difference from the dynamics of the vapor bubble in a large volume. There are also qualitative differences in the nature of motion of the vapor bubble and that of the gas bubble. This is due to the fact that the mass of the gas bubble and the temperature of the liquid do not change during the rise near the bubble, whereas the mass of the vapor bubble and the temperature of the vapor in the bubble and the liquid near the bubble can vary significantly due to evaporation of the liquid and steam condensation. This is due to the change of bubble height and level of fluid in the tube. The liquid level in the tube depends on the height of the bubbles, but the height of the liquid level in the tube depends on the volume of the bubbles.
On efficiency of metal hydride extraction of hydrogen from a mixture with methane
Authors: Dunikov D O , Blinov D V 
Published: November 2019

Abstract
Extraction of hydrogen from dilute mixtures with natural gas differs from traditional separation processes, since hydrogen is the minor component with low partial pressure. Metal hydrides absorb hydrogen selectively and can be used for purification. Exergy analysis shows that the metal hydride separation of binary mixture of a gas with hydrogen has a maximum at hydrogen content of 5-15%, and the main factors affecting efficiency are the need to spend heat to compensate the reaction enthalpy and pressure losses of methane during filtration through the metal hydride bed. We have experimentally demonstrated successful separation of the hydrogen (10%) – methane (90%) mixture at inlet pressure of 9.5 bar by the LaNi4.8Mn0.3Fe0.1 intermetallic compound in one step with roundtrip (absorption/ desorption) hydrogen recovery of 74% and absorption hydrogen recovery of 76%, which is close to the value of 77% calculated based on the thermodynamic analysis.
Simulation of evaporation of mixtures and solutions in the spheroidal state
Authors: Elistratov S L , Mironova N V 
Published: November 2019

Abstract
The paper presents the theoretical dependences of evaporation in the spheroidal state of pure liquids, liquids containing insoluble and partially soluble impurities. The conditions are formulated, upon the occurrence of which a change in the crisis regime of film evaporation to an intensive regime of partially bubble boiling may occur upon contact with a heating surface.
Numerical simulation of the heat transfer of staggered drop-shaped tubes bundle
Authors: Deeb R , Sidenkov D V 
Published: November 2019

Abstract
Tube bundles can be used as a separation heat exchanger in the “organic” Rankine cycle power plants (ORC), while the hot gas passes over the outer surface, and the working substance ORC flows inside the tubes. A numerical study has been conducted to clarify heat transfer and hydrodynamics of a cross-flow heat exchanger with staggered drop-shaped tubes at different flow angles of attack (θ). A mathematical and numerical model in software package ANSYS has been developed for numerical evaluation of heat transfer and flow field of a bundle of drop-shaped tubes, with taking into account the strain caused by different pressures inside and outside the tubes. The results of numerical simulation of pressure, velocity, temperature distribution in the tube’s bundle had provided the development of equation to determine the average Nusselt number (Nu) in terms of Reynolds number (Re), Prandtl number (Pr) and angle of attack.
Reasons for tangerine peel utilization in the composition of mixed fuels based on bituminous coal
Authors: Yankovsky S A , Tolokolnikov A A , Cherednik I V , Kuznetsov G V 
Published: November 2019

Abstract
Application analysis of processed tangerine peel in a mixture with T grade coal (lean) as a fuel for hot water boilers is presented. Technical characteristics, as well as conditions and ignition delay times for such mixed fuels at different mass concentrations of the initial components, have been experimentally determined. The experiments were carried out in air at temperatures from 600 ° C to 800 ° C. Record of ignition and combustion processes of composite fuel samples was carried out using a high-speed video camera (image format — 1024 × 1024 pixels, frame rate — up to 1000000 per second), which ensures high discretization of the recording results of characteristic process times. A temperature limit has been identified for the stable ignition of such fuels. It has been established that an increase of tangerine peel proportion in the mixture leads to acceleration of ignition processes of the studied mixed fuels. Reasons for application of fuel mixtures based on bituminous coal and food waste in the small energy sector have been provided.
Two-dimensional steady-state heat conduction problem for heat networks
Authors: Nemirovsky Y V , Mozgova A S 
Published: November 2019

Abstract
The method of determining the level of heat losses through structures of heat networks and the two-dimensional steady-state heat conduction problem for multilayer structures of heat networks have been considered, given that each of the layers has its own physical properties and heat transfer coefficients depend on r and z coordinates. The definition of heat losses is an important practical task, since they are one of the main indicators of energy efficiency in the operating heat networks and are included in heat tariffs.
Formation of the lamellar structure and recrystallization at the disorder → order transition in Au35.3Cu52.6Pd12.1 alloy
Authors: Aleksandrova S S , Medvedeva E V 
Published: November 2019

Abstract
The atomic ordering in the Au35.3Cu52.6Pd12.1 alloy was studied by field ion microscopy. It was found that the removal of internal stresses in the alloy during the disorder → order transition occurs due to the formation of c-domain lamellas from 2 to 10 nm wide at the early stages of ordering. The use of computer modeling for the interpretation of ion images provided with the identification and evaluation of the superstructural defects quantitative characteristics.
Mechanoluminescence of composite layer applied on polymer surface excited by short acoustic pulses in water
Authors: Banishev A F , Shubny A G , Banishev A A 
Published: November 2019

Abstract
A composite mechanoluminescent layer has been produced on the surface of polymethylmethacrylate by liquid-phase embedding of SrAl2O4:(Eu2+, Dy3+) phosphor microparticles into the polymethylmethacrylate surface layer. The photoluminescence and mechanoluminescence of the obtained layer have been investigated. The mechanoluminescence was excited by the short acoustic pulses. A possible mechanism of mechanoluminescence excitation is under discussion. The produced composite layer is shown to exhibit high efficiency of “mechano-optical” transformation.
Increasing of an electrostatic probe capacity and efficiency for metal dust collection in ITER
Authors: Begrambekov L B , Bidlevich O A , Grunin A V , Voityuk A N 
Published: November 2019

Abstract
Formation of dust particles and clusters is observed in almost all modern fusion devices. Accumulation of dust in next-generation thermonuclear installations can significantly affect plasma parameters and lead to accumulation of unacceptably large amounts of tritium. The use of a specially developed electrostatic probe is planned in the international thermonuclear experimental reactor ITER to collect dust for further analysis. The article describes a numerical model of dust particles movement in an electrostatic probe. Dust particles trajectories inside the probe were analyzed. Several electrostatic probe design modifications were proposed on the basis of the analysis in order to increase the efficiency of dust collection.
Thermal desorption study of hydrogen isotopes trapping and its diffusion in tungsten coated with aluminum/beryllium layer during plasma irradiation
Authors: Begrambekov L B , Kaplevsky A S , Dovganyuk S S , Kasimova N N 
Published: November 2019

Abstract
The influence of irradiation in hydrogen plasma with oxygen impurity on the penetration of hydrogen isotopes through the surface of tungsten, through the surface of beryllium and aluminum layers on tungsten, and through the tungsten-coating interface was studied. It was shown that all these processes are accelerated in the presence of oxygen impurity in plasma. A conclusion is made that detritisation of the surface of both in the conditions of a fusion reactor tungsten and beryllium is possible.
Elaboration of pulsed X-ray laser on base of radiation fluxes waveguide-resonance propagation phenomenon
Authors: Egorov V K , Egorov E V 
Published: November 2019

Abstract
The work presents short characteristics of the radiaiton fluxes waveguide-resonance propagation phenomenon opened in result of X-ray characteristic radiation transportation peculiarities study by planar extended slit clearance functioned in frame of its total external reflection phenomenon. There are showed that the waveguide-resonanec phenomenon must become apparent in frame of the Bragg reflection phenomenon and can be used for elaboration of the Bragg-Laue waveguide-resonance cells (BLWRC). Set of BLWRCs can be used for construction of compact pulsed X-ray laser in form of circular radiation storage. There are presented and discussed its expected parameters.
Effect of duration of titanium microarc treatment on morphology, composition and electrochemical behavior of coatings
Authors: Gerasimov M V , Bogdashkina N L , Kondratsky I O , Peretyagin P Yu , Suminov I V , Filonova E V , Shcherbakov A I , Apelfeld A V 
Published: November 2019

Abstract
Microarc oxidation (MAO) of titanium grade VT1-0 was carried out in the alkaline electrolyte with the addition of nickel sulfate. The effect of duration of titanium microarc treatment on morphology, composition and electrochemical behavior of coatings was investigated. It was found that nickel appears in MAO coatings only after a certain duration of the MAO treatment process (from 5 to 10 min), when the temperature in the micro-discharges becomes high enough for thermolysis of nickel sulfate and incorporation of its oxide into the coating (respectively, with a thickness of 2 to 5 μm). MAO coatings, despite their relatively small thickness, significantly increase the corrosion resistance of titanium in 25% sulfuric acid (anodic passivation currents are reduced up to 2 orders of magnitude).
Mechanism of internal stress formation in titanium alloy samples, obtained by additive manufacturing
Authors: Grushin I A , German M A , Kuzmina D A 
Published: November 2019

Abstract
The paper presents the results of residual stress formation study in Ti-6Al-4V alloy samples, obtained by additive manufacturing. An analogy of residual stress formation mechanism observed in samples during 3D-printing and laser beam welding technology is shown. The effect of annealing on residual stress level is investigated.
Tribological behavior of coatings deposited by reactive magnetron sputtering of silicon in acetylene-nitrogen gas mixtures
Authors: Khrushchov M M , Marchenko E A , Antonova O S , Atamanov M V , Petrzhik M I , Sulandziga D A 
Published: November 2019

Abstract
The composition, micromechanical properties and tribological behavior of silicon-based coatings obtained by reactive magnetron sputtering of silicon have been investigated. The results of the friction fatigue tests and the peculiarities of the friction surface failure in several types of vapor-deposited silicon-based coatings have been discussed.
Low-temperature ion nitriding of VT6 titanium alloy with UFG structure
Authors: Khusainov Yu G , Nikolaev A A , Agzamov R D , Ramazanov K N , Esipov R S 
Published: November 2019

AbstractThis work describes the effect of low-temperature ion nitriding on the mechanical and operational properties of the titanium alloy VT6 with the ultrafine-grained structure. Ion nitriding of the alloy was carried out atT=450-600 °C andp=300 Pa in a gas mixture of argon and nitrogen during 6 hours. Low-temperature nitriding at the temperature ≥550 °C leads to a decrease in the microhardness of the material base. The optimum processing temperatures are 450-500 °C. The formation of the UFG structure and subsequent nitriding increases wear resistance by 28%.
Change of photoelectric elements power characteristics by silver nanoclusters modification of receiving surface
Authors: Krit B L , Fedotikova M V , Sleptsov V V , Kukushkin D Yu , Gorozheev M Yu , Kuvshinov V V , Morozova N V 
Published: November 2019

Abstract
The values of power characteristics of modern photovoltaic cells are considered. Possibility of their increasing with the aid of surface plasmon resonance reached by modification of the receiving surface with silver nanoclusters is presented. The effect of nano-coating on the power and stability of energy generation is shown.
Study of the ion assisted sputtering process parameters influence on the structure and morphology of TiPb coatings
Authors: Lozovan A A , Betsofen S Y , Lyakhovetskiy M A , Lesnevskiy L N , Bespalov A V , Nikolaev I A , Pavlov Y S , Aleksandrova S S 
Published: November 2019

Abstract
The paper presents the study’s results of the composition, structure and morphology of Ti-Pb coatings formed by magnetron co-bombarded with the help of ions. The effect of the relationship between magnetron currents on the structure of Ti and Pb coatings is shown.
The effect of current frequency on the structure, composition and properties of oxide layers formed by plasma electrolytic oxidation on aluminum-silicon alloy
Authors: Polunin A V , Borgardt E D , Ivashin P V , Tverdokhlebov A Ya , Krishtal M M 
Published: November 2019

Abstract
Oxide layers formed by plasma electrolytic oxidation (PEO) on pre-eutectic aluminum-silicon alloy 361.0 (9.8 wt.% Si) at various current pulse frequencies (50, 500, and 1000 Hz) were investigated. Scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDXMA), x-ray diffraction analysis (XRD) were applied for the investigation of the oxide layers. Thickness, roughness, microhardness, wear resistance and thermal conductivity of the obtained oxide layers were measured. It was found that at a forming current frequency of 500 Hz, the best productivity of forming of the oxide layer is achieved, and the layer has the best hardness and wear resistance, and the smallest roughness.
Influence of parameters of high-voltage electrospark dispersion of materials on granulometric composition of nanopowders
Authors: Savkin A V , Sleptsov V V , Kukuskin D Y , Tsyrkov R A 
Published: November 2019

Abstract
The influence of parameters of high-voltage electric spark dispersion of materials on the granulometric composition of nanopowders of metals and alloys is considered. The most interesting feature of the developed experimental setup is the presence of an air discharge gap (FV1), which creates an overvoltage on the working discharge gap (FV2). The discharge gaps form a voltage divider when the capacitor (C) is discharged. It was assumed that the voltage divider should have a significant impact on the operation of the experimental setup. Studies have shown that when the air gap (FV1) is much larger than the working gap (FV2), their exact ratios do not affect the size of the resulting nanoparticles. At such ratios of discharge gaps, the voltage divider allows to regulate only the performance of the process of obtaining nanopowders. The resulting silver nanopowders had a spherical shape and a rather narrow size distribution. It is necessary to further study the process of high-voltage spark dispersion of materials with a significant overvoltage of the discharge gap.
Influence of VIP treatment modes on nitride coatings formation with different crystallographic orientation
Authors: Smirnova A N , Petrov L M , Ashmarin A A , Ivanchuk S B , Semenov V D 
Published: November 2019

Abstract
The change in crystallographic orientation during nitride coatings formation based on titanium and zirconium is studied depending on changes in the concentration ratios for the gas and metal components of the plasma flows and their energy effects on the treated substrate during vacuum ion-plasma (VIP) treatment. It is shown that a decrease in the interaction energy of the gas-metal plasma flow with the surface contributes to the transition of the texture formation of the phase composition to the non-texture.
Residual stress in the surface layers of high-pressure compressor blades made of titanium alloys after surface treatment with high-current pulsed electron beams
Authors: Teryaev D A , Mokhov V S 
Published: November 2019

Abstract
The paper deals with the evaluation of residual stresses in the surface layer of titanium alloys as a result of electron beam processing and solving problems associated with increasing heat resistance, corrosion resistance, and fatigue strength.
Ti-Al system coatings synthesized in reaction gases
Authors: Vardanyan E L , Ramazanov K N , Nazarov A Yu , Nagimov R Sh 
Published: November 2019

Abstract
The results of the study of reaction gases influence on microhardness and adhesion properties of coatings based on the Ti-Al intermetallic system. The results of different reaction gases influence on the coatings properties are discussed. The tests result of the samples with a single-layer coating based on Ti-Al intermetallic deposited in the reaction gas environment showed that the coating deposited in the nitrogen environment has the highest elastic recovery coefficient and has approximately the same fracture onset load compared to coatings deposited in the oxygen and acetylene environments.
Cognition of complexity and trade-offs in a wildfire-prone social-ecological system
Authors: Hamilton M , Salerno J , Fischer A P 
Published: November 2019

Abstract
Wildfire risk is a defining environmental challenge throughout much of the American West, as well as in other regions where complex social and ecological dynamics defy simple policy or management solutions. In such settings, diverse forms of land use, livelihoods, and accompanying values provide the conditions for trade-offs (e.g. between protecting homes from uncontrollable fires and restoring low-severity fire to ecosystems as a natural disturbance process). Addressing wildfire risk requires grappling with these trade-offs at multiple levels—given the need for action by individuals as well as by large and diverse stakeholder groups—and under conditions of considerable complexity. We evaluated how individual and collective perception of trade-offs varies as a function of complexity through analysis of the cognitive maps—representations of perceived causal relationships among factors that structure an individual’s understanding of a system—of 111 stakeholders in the Eastern Cascades Ecoregion of central Oregon. Bayesian statistical analysis revealed a strong tendency against perception of trade-offs in individual maps, but not in a collective map that resulted from the aggregation of all individual cognitive maps. Furthermore, we found that lags (the number of factors that mediated the effect of an action on multiple valued outcomes) limited perception of trade-offs. Each additional intervening factor decreased the likelihood of a trade-off by approximately 52% in individual cognitive maps and by 10% in the collective cognitive map. However, the heterogeneity of these factors increased the likelihood of perception of trade-offs, particularly among individual cognitive maps, for which each unit increase of the Shannon diversity index translated into a 20-fold increase in the likelihood of perception of trade-offs. Taken together, these results suggest that features of complexity have distinct effects on individual—and collective-level perception of trade-offs. We discuss implications for wildfire risk decision-making in central Oregon and in other complex wildfire-prone social-ecological systems.
Identifying trade-offs and co-benefits of climate policies in China to align policies with SDGs and achieve the 2 °C goal
Authors: Liu Jing-Yu , Fujimori Shinichiro , Takahashi Kiyoshi , Hasegawa Tomoko , Wu Wenchao , Takakura Jun’ya , Masui Toshihiko 
Published: November 2019

Abstract
The Paris Agreement set long-term global climate goals to pursue stabilization of the global mean temperature increase at below 2 °C (the so-called 2 °C goal). Individual countries submitted their own short-term targets, mostly for the year 2030. Meanwhile, the UN’s sustainable development goals (SDGs) were designed to help set multiple societal goals with respect to socioeconomic development, the environment, and other issues. Climate policies can lead to intended or unintended consequences in various sectors, but these types of side effects rarely have been studied in China, where climate policies will play an important role in global greenhouse gas emissions and sustainable development is a major goal. This study identified the extent to which climate policies in line with the 2 °C goal could have multi-sectoral consequences in China. Carbon constraints in China in the 2Deg scenario are set to align with the global 2 °C target based on the emissions per capita convergence principle. Carbon policies for NDC pledges as well as policies in China regarding renewables, air pollution control, and land management were also simulated. The results show that energy security and air quality have co-benefits related to climate policies, whereas food security and land resources experienced negative side effects (trade-offs). Near-term climate actions were shown to help reduce these trade-offs in the mid-term. A policy package that included food and land subsidies also helped achieve climate targets while avoiding the adverse side effects caused by the mitigation policies. The findings should help policymakers in China develop win–win policies that do not negatively affect some sectors, which could potentially enhance their ability to take climate actions to realize the global 2 °C goal within the context of sustainable development.