bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulmonary Edema in the Acute Stage of Rheumatic Fever Treated with Double-Valve Replacement in a Pediatric Patient
Authors: Yozgat Yilmaz , Uzuner Selcuk , Yesilbas Osman , Ogur Mustafa , Yakut Kahraman , Yozgat Can Yilmaz , Temur Hafize Otcu , Ay Yasin 
Published: November 2019

AbstractCardiogenic pulmonary edema (CPE) is a rare clinical condition of acute rheumatic fever (ARF) in the early stage. Generally, CPE can be convalesced by steroid and anticongestive treatment. Herein, we describe a case of a 14-year-old boy with ARF presenting with bilateral pulmonary edema secondary to acute mitral and aortic insufficiency. In this case, the pulmonary edema of ARF was successfully managed by combined surgical replacements of both valves.
Analytical Beamlet Code 3D for neutral beam injectors: principles and applications
Authors: Harder N den , Rittich D , Orozco G , Hopf C 
Published: November 2019

Abstract
Neutral beam injection is the main heating system on a variety of fusion devices, and will be the main heating system of ITER. Especially during high-power operation in long pulse devices, it is important that transmission losses and power deposition in the beamline are well quantified. This paper presents the analytical beamlet code (ABC)3D. ABC3D is based on analytical Gaussian beamlets, and includes shadowing effects. The code is able to calculate emission spectra in the beamline, duct transmission losses, and neutral beam power loads on 3D components. Examples of its application are shown that highlight key results in beam emission spectroscopy, beamline design, and geometry verification in experiments. Limitations to the computational approach are discussed on the basis of a comparison with more advanced calculations.
Thermal-hydrodynamic design of energy-efficient surfaces with inclined oval-trench vortex generators
Authors: Isaev S A 
Published: November 2019

Abstract
In the present study it is found that enhancement of air turbulent flow and heat transfer at Re=104 is influenced by a set of one-row oval-trench dimples of depth 0.25 inclined at an angle of 65° to the incoming flow and located at the heated wall of the rectangular (9×1) narrow channel when the dimple step H is varied. The periodic section of the dimpled channel 8 in length is considered. The dimple step H is varied from 8 to 2. Abnormal enhancement of flow and heat transfer at H=2 is followed by both a 4-fold decrease in relative negative friction and a 6.5-fold increase in relative heat transfer in the separated flow zone. The phenomenon of turbulent flow acceleration with a 1.39-fold increase in the maximum flow velocity (at H=2) in the dimpled narrow channel in comparison to the plane-parallel channel is discovered.
Numerical analysis of the leaflet elasticity effect on the flow in the model of a venous valve
Authors: Gataulin Y A , Yukhnev A D , Smirnov S I , Rosukhovskiy D A 
Published: November 2019

Abstract
The paper presents the results of the numerical study of the flow in a symmetric model of the venous valve with different leaflet elasticity. The focus is on the analysis of the velocity field and the stagnant region. The stagnant region behind the valve is of great practical interest for phlebologists in terms of the potential for the formation of blood clots. The constructed simplified model of the venous valve has given a good qualitative agreement with the clinical ultrasound data on the position of the valve leaflet and the stagnant zone behind the valve.
The flow regimes of the annular swirling turbulent jet
Authors: Ryzhenkov V O , Abdurakipov S S , Mullyadzhanov R I 
Published: November 2019

Abstract
We perform Large-eddy simulations (LES) of an annular swirling turbulent jet. The swirl parameter is considered within the range S = 0.3−0.6. The Reynolds number based on the bulk velocity and outer pipe diameter is 8900 while the outer to inner diameter ratio is 2. We obtain different flow regimes without and with the vortex breakdown occurring for S = 0.4. Coherent vortical structures for each regime are indentified using the azimuthal Fourier decomposition and the Proper orthogonal decomposition (POD). The turbulent kinetic energy accumulates in the first POD modes with the azimuthal number m = 1.
Numerical simulation of heat and moisture transfer in co-current membrane heat exchangers
Authors: Naumkin V S , Nizovtsev M I 
Published: November 2019

Abstract
The paper presents the mathematical model, based on the narrow-channel approximation, for calculating the processes of heat and moisture transfer in membrane heat exchangers and taking into account possible condensation on heat exchange surfaces. The possibility of humidifying the supply air with moisture from the exhaust air in the cold period is considered. It is shown that the membrane co-current heat exchangers can operate without freezing up to the outdoor temperature equal to -20 °C.
Numerical simulation of the electrovortex flow in the non-inductive approximation under the influence of an external magnetic field
Authors: Vinogradov D A , Teplyakov I O , Ivochkin Yu P 
Published: November 2019

Abstract
The results of a numerical study of the structure of an electro-vortex flow under an external magnetic field are presented. It was shown that an external magnetic field can lead to both an increase and a decrease in the intensity of the flux. At the same time, it is necessary to control the external magnetic field in direct current arc furnaces very carefully, since the non-optimal external magnetic field leads to the suppression of the flow in the melting bath.
Influence of controlled pulsations of a liquid flow on the surface temperature of heater with a high heat flux
Authors: Eloyan K S , Kreta A S 
Published: November 2019

Abstract
The removal of high heat fluxes from 100 W/cm2 to 1000 W/cm2 for microelectronics components is one of the difficult tasks in the field of applied thermal physics. One of the important parameters in the task of cooling the intensely heated surfaces of the elements of microelectronics is the surface temperature depending on the operation time. This work is an experimental study of the influence of controlled pulsations of a liquid flow in a two-phase system on the temperature of the heater surface depending on the heat flux. It is shown that for a heat flux of more than 80% of the critical heat flux, the temperature change on the surface of the heater can reach up to 15 °C, which can adversely affect the operation of the cooled chip. In the case of less than 80% of the critical heat flux, the temperature change is less than 4 °C, allowing the cooled chip to work in a stable mode. It is shown that in the case of controlled pulsations of the liquid flow, subregimes are formed with different duration of existence.
Study of Rain Simulation for Aircraft Engine Certification
Authors: Guryanov A I , Evdokimov O A , Veretennikov S V , Guryanova M M , Kalinina K L 
Published: November 2019

Abstract
Engine tests under flight conditions are extremely important at the stage of its complex debugging. These conditions include the simulation of icing, check for the penetration of birds in the inlet vanes, modeling hail and rain. Simulation of rain due to its significant unsteadiness need providing requirements for the concentration of water in the air, the distribution spectrum of droplets by size, the value of the average diameter of the droplets, the mass flow rate curves for the injectors and the conditions of interaction of droplets with air. This paper contains information about the developed method of calculating the characteristics of the injector for the necessary modes of water injection into the engine as well as experimental study of the injector and conducted studies of the parameters of its operation process, including the choice of optimal modes. As a result of the research, an injector was developed that allows to obtain the average median diameter of 2.66 mm and droplets of the certification spectrum. Also there was worked out the schematic diagram of the collector module of the installation for rain simulation that meets the certification requirements: simulation of rain in the “idle power” and “take-off” modes with the condition of simultaneous provision of water concentration in the air of 20 g/m3 and the average median diameter of 2.66 mm. This installation provides operation in transient modes with the condition of maintaining the water concentration in the air of 20 g/m3.
Unsteady model of wall-adjacent boiling subcooled liquid flow
Authors: Levin A A , Chudnovsky V M 
Published: November 2019

Abstract
We discuss an approach to constructing a mathematical model of formation and dynamics of the vapor phase on the heat-releasing surface under conditions of unsteady heat flux. We focus on nucleate boiling, since its predictive model is at present most difficult to design. The nucleate boiling stage is described in the form of a homogeneous model that accounts for the heat fluxes associated with the vapor phase presence. The stage of film boiling takes into account the dynamics of a pulsating vapor layer and its heat exchange with subcooled liquid and the heat-releasing surface.
Determination of the vapor film thickness at steady superfluid helium film boiling
Authors: Puzina Yu Yu , Kryukov A P , Yachevsky I A 
Published: November 2019

Abstract
Heat mass transfer processes at superfluid helium boiling is considered for different conditions. Mathematical description is formulated with taking into account the peculiarities of superfluid helium. System of equations is based on the methods of continuum mechanics and molecular kinetic theory. Pressure distribution in the liquid is determined by the hydrostatic difference. At the vapor-liquid interface the Laplace formula is used. The vapor pressure in the film is determined by the non-equilibrium effects in the vapor near the interface. Heat transfer in a liquid is described by the Gorter-Mellink semi-empirical theory. Experimental data on the stationary boiling of superfluid helium under various conditions are interpreted based on the formulated mathematical model. For all cases in the considered range of parameters, the qualitative and in some cases quantitative agreement between the calculated and experimental values of the vapor film thickness were obtained.
Simulation of structure and thermodynamic properties of the double of ozone and carbon dioxide hydrates using molecular and lattice dynamics methods
Authors: Bozhko Yu Yu , Gets K V , Subbotin O S , Belosludov V R 
Published: November 2019

Abstract
Ozone is a very effective medical, industrial and agricultural disinfector, bleacher and deodorizer. Ozone acts very quickly, but its decay rate is also high. Gas hydrate formation is a promising method for storing ozone and ozone-containing gas mixtures. We use molecular dynamics (conjugate gradient) and lattice dynamics method to calculate the free energy double O3+CO2 hydrate of cubic structure I at 270 K and 275 K temperatures and various gas phase compositions. It allowed determining the chemical potential of water molecules depending on pressure at given temperatures and compositions. Comparison with Ih ice and liquid water allowed us to determine regions of O3+CO2 double hydrate stability. The presented results may be useful in studies of thermodynamic stability areas of hydrates obtained from pure ozone (e.g. liquid ozone), its mixtures and in the development of corresponding storage technologies.
Combustion of aluminum and boron powders suspended in the air
Authors: Moiseeva K M , Yu Krainov A 
Published: November 2019

Abstract
This paper presents results on the numerical solution of the flame propagation problem in the air with suspended aluminum and boron particles. The aim of the study is to determine the combustion rate of the Al-B-air mixture depending on the particle mass concentration and its size. The physical and mathematical model of the process is based on the approaches of the mechanics of two-phase reactive media. The numerical method for solving the problem is based on the decay algorithm of an arbitrary discontinuity. It is shown that the apparent burning rate of the aerosol suspension of the mixture of aluminum and boron powders slightly decreases with an increase in the mass fraction of the powder in the mixture.
On a compact finite-difference scheme of the third order of weak approximation
Authors: Ostapenko V V , Polunina E I , Khandeeva N A 
Published: November 2019

Abstract
The stability and accuracy of compact difference schemes with artificial viscosities of the fourth divergence order are studied. These schemes have a third order both of classical approximation on smooth solutions and weak approximation on discontinuous solutions. As a result of the stability analysis of these schemes in the linear approximation, the optimal values of their viscosity coefficients were obtained. Test calculations are presented to demonstrate the advantages of the new compact scheme compared to the TVD and WENO schemes when calculating discontinuous solutions with shock waves.
Influence of surface currents on the nutrient fluxes from the shelf to the deep part of the Black Sea
Authors: Dorofeyev V L , Sukhikh L I 
Published: November 2019

Abstract
Functioning of marine ecosystems strongly depends on nutrient supply. One of the key sources of nutrients in the Black sea is rivers runoff, concentrated mainly on the northwestern shelf (NWS). Due to surface currents waters from NWS propagate into deep part of the basin and transport nutrients into interior basin. Study of this exchange of water mass and nutrients between the NWS and the deep part of the Black Sea is a goal of this work. It is based on the results of numerical modelling evolution of physical and biogeochemical fields of the Black Sea. The interdisciplinary model of the Black Sea ecosystem consists of a circulation model and a biogeochemical one, describing the interactions between different components of the marine ecosystem. It is shown, that nutrient fluxes between NWS and deep sea are defined by intensity and character of surface currents, which depend on regional wind stress vorticity.
Computational and experimental research of a steam turbine system for an intra-cycle compression of fuel
Authors: Borisov Yu A , Pugachuk A S , Sinkevich M V , Khalife H 
Published: November 2019

Abstract
The paper deals with the design of highly efficient small-size turbines. A method for designing a steam gas turbine using numerical methods for calculating the working processes in the flow section is described. The results of the calculated and theoretical research, which allowed determining the main characteristics of the turbine, are given. The estimated efficiency of the resulting turbine was not less than 85%. The results of tests in the model conditions of the model turbine, manufactured using additive technology, are presented. A comparison of experimental and calculated data has led to the conclusion about the adequacy of the developed mathematical model used in the calculated and theoretical research.
Calibration error minimization method of three-dimensional geometry optical meter with two photodetectors
Authors: Ovchinnikov N N , Dvoynishnikov S V , Glavny V G , Yu Sadbakov O , Shepihin I V 
Published: November 2019

Abstract
The paper presents a method for minimizing the calibration error of a triangulation three-dimensional geometry meter with two photodetectors, ensuring a reduction in the calibration error using the method of an arbitrarily oriented flat calibration object in the measuring volume. The method is based on minimizing the deviation from flatness of the result of the reconstruction of a three-dimensional image of a calibration object and can be used in the algorithm for automatic calibration of a triangulation meter of three-dimensional geometry with two photo-receivers.
On the determination of the transfer coefficients in the heat and mass transfer equations, based on the Boltzmann equation
Authors: Anisimova I V , Ignat`ev A V , Zhukova O G 
Published: November 2019

Abstract
At present, as a rule, the determination of the transfer characteristics of viscosity, diffusion, heat conduction and other characteristics in macro-equations of aerohydromechanics is carried out experimentally or on the basis of the kinetic theory of gases - the Boltzmann equation. The right “collisional” part of the Boltzmann equation contains multiple improper integrals with an oscillating integrand function, the values of which are used in determining transfer coefficients. This article proposes numerical algorithms suitable for calculating integrals of this type. They are based on the use of the Gauss - Christoffel quadrature formula that applies orthogonal polynomials. The oscillation nature of the integrand requires control of the quadrature error. In this case, the split nodes of the integration interval are distributed on the basis of minimizing the error of approximation of the integrand by orthogonal polynomials. Such an approach, in contrast to others, allows determining the values of integrals with oscillating integrand functions more qualitatively and efficiently and does not contain an “iterative” procedure for increasing the split nodes of the integration segment to achieve a given accuracy. This article is devoted to the problem of constructing quadrature formulas for calculating improper integrals, which are used in determining the transfer coefficients, based on the Boltzmann equation.
The effect of density turbulent diffusion intensity on magnetohydrodynamic wave processes in a spherical layer of electrically conducting liquid
Authors: Peregudin S , Peregudina E , Kholodova S 
Published: November 2019

Abstract
The paper considers large-scale 3D wave motion of weakly compressible and perfectly conducting inhomogeneous inviscid liquid subject to a magnetic field and the Coriolis force, with due account the spherical topography of bounding surfaces. The results of the studies can be used in geophysics and astrophysics, and in particular, in the study of dynamical processes occurring in the Earth liquid core and in stellar interiors. Moreover, they can be also employed in evaluation of magnetohydrodynamic characteristics of a liquid medium and for estimation of the parameters of the wave disturbance in the electromagnetic field induced by the corresponding hydrodynamic excitement. In addition, the above results can be used in the study of magnetohydrodynamic processes in engineering devices and in the study of foreground energy materials.
Inner aerodynamics of the improved four-vortex furnace model
Authors: Alekseenko S V , Yu Shadrin E , Anufriev I S , Boyko E E , Mukhina M A 
Published: November 2019

Abstract
The internal aerodynamics of a perspective vortex furnace chamber of a pulverized coal boiler with a diagonal arrangement of burners is studied using the non-contact optical method of flow diagnostics: Particle Image Velocimetry - PIV. The results of PIV measurements, characterizing the complex spatial structure of a swirled flow in an isothermal laboratory model of the furnace device, are presented. The velocity distribution in the vortex chamber volume is obtained, and the flow structure in the form of four conjugate closed vortices with curved axes is visualized.
Ignition of granulated mixed fuel based on lignite and wood waste
Authors: Yankovsky S A , Cherednik I V , Kuznetsov G V 
Published: November 2019

Abstract
Analysis of utilization possibility of sawmill waste when burning pellets in a mixture with coal. Conditions and characteristics of pellets ignition of fuel mixtures based on coal dust and fine wood at various mass concentrations of the components have been experimentally determined. Fuel pellets were made by cold pressing on a hydraulic press. The experiments were carried out in a medium heated to high (from 600 ° C to 800 ° C) temperatures of still air. It was established that increase of wood component proportion in the fuel granule significantly reduces the values of ignition delay times of all studied mixtures based on brown coal of 3B grade. The limit of stable ignition of such fuels is 600 ° C. The obtained results reflect the possibility of using granules of mixed fuels based on crushed coal and wood in the case of fuel-bed combustion in coal-fired boilers, as well as hot water boilers.
Experimental investigation of the effect of volume concentration and average diameters of nanoparticles on the contact angle of wetting between nanofluids and different substrates
Authors: Lobasov A S , Minakov A V , Pryazhnikov M I 
Published: November 2019

Abstract
The influence of different volume concentrations and average diameters of Al2O3 nanoparticles on the contact angle of wetting between nanofluids and different substrates was experimentally investigated. The concentrations of aluminium oxide nanoparticles were varied from 0.0625 vol.% to 1 vol.%. The average diameters of aluminium oxide nanoparticles were varied from 43 nm to 150 nm. Andesite, diabase, gabbro-diabase and metabasalt were chosen as the substrates. The dependences of the value of the contact angle of wetting between nanofluids and different substrates were obtained as a result of the experiments. It was shown, that the contact angle of wetting nonlinearly depended on the nanoparticles volume concentration. In addition, it was found that the wetting angle also depends on the substrate material, on which the drop lies. It was also obtained that the contact angle of wetting between different substrates and nanofluids with average and huge nanoparticles (> 75 nm) increased 1.25-1.5 times even at the smallest concentration (0.0625 vol.%) and then achieved the plateau. In contrast, the contact angle of wetting between different substrates and nanofluids with small nanoparticles (< 50 nm) reached maximum at a concentration of 0.0625 vol.% and after that slowly decreased to the values lower than those for the pure water.
Peculiarities of the “brass” coating formation applied by gas-dynamic spraying
Authors: Arkhipov V E , Dmitriev V G , Moskvitin G V , Pugachev M S 
Published: November 2019

Abstract
A research of the “brass” type coating structure generation process, obtained by gas-dynamic spraying from a particulate mixture of copper, zinc and corundum. The formation mechanisms of the phase and chemical composition of the obtained coating are determined. During the coating formation, mass-transfer of zinc microvolumes by corundum particles occurs and their interstitial dissolution into copper particles, while diffusion processes occur by the motion of vacancies, of copper to zinc with the formation of intermetallic compounds.
The effect of metallization on the sorption properties of carbon textile Busofit
Authors: Borisov A M , Gorina V A , Ditileva A O , Kovalev I A , Korobeynikov E V , Sleptsov V V , Suminov I V , Cheblakova E G , Schur P A 
Published: November 2019

Abstract
The effect of a titanium coating on the sorption properties of carbon textile Busofit was studied. The BET specific surface area was about ·103 m2/g before and after metallization of the fiber. The micropore volume in samples accounted for most of the total pore volume.
Optical properties of fluorocarbon coatings obtained by ion-plasma method at atmospheric pressure in dynamic mode of deposition
Authors: Elinson V M , Shvedov A V , Kukushkin D Yu 
Published: November 2019

Abstract
This paper presents the results of a study of the formation of fluorocarbon coatings obtained by using a low-frequency plasmatron of a low-temperature atmospheric pressure plasma in a dynamic mode of deposition. The main dependences of chemical vapor deposition (CVD) are investigated. The absorption spectra in the UV range was studied, and the band gap was determined by the Tauc method.