bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of synthetic bio-phenol resins derived from biomass gasification in bio-adhesive formulation
Authors: Khezri R , Alias A B , Abdul Karim W A W , Motlagh S R
Published: December 2019

Bio-phenol formaldehyde adhesives formulated from sustainable biomass sources is an excellent alternative to phenolic petroleum-based adhesives with lower pollution level. This study aimed to formulate bio-adhesive from two types of biomass namely palm kernel shell (PKS) and Leucaena sp. Wood. The intention was to find the best process condition which results in maximum content of bio-phenol in the product. The bio-based phenolic resins (bio-oils) were produced from gasification process and their physical and chemical properties were determined. Both produced bio-oils were involved in formulation of bio-based phenol formaldehyde adhesives (resinification) at different operating conditions (temperature, time and catalyst loading). The chemical functional groups and individual compounds of the phenol resins and bio-adhesive samples were identified by GC-MS. The results indicated that temperature has persistent increasing effect on phenol percent of the bio-oil from Leucaena sp. wood however for the bio-oil from PKS the increase of phenol was until the temperature of 85 °C. Reaction time and catalyst loading were observed to have similar effects on resinification of both bio-oil samples. The bio-adhesive produced under best operating condition has the highest amount of bio-phenol and therefore is considered an environmental friendly adhesive with lower cost and pollution than the petroleum-based types.
Eliminating waste using lean tools and delmia quest simulation
Authors: Hashim S M , Rabilah R , Shah A M
Published: December 2019

Manufacturing industries and servicing providers have successfully implemented lean tools during managing and controlling the activities. This study was carried out at pickle manufacturer one of Small Medium- sized Enterprise (SME) in Malaysia to reduce non-value added activities using some tools from time and motion study and Delmia Quest software. Solutions were suggested to reduce non-value added activities which yielded improvement of 24% and 36% in labor utilization and 25% in daily output.
Heterogeneous fenton-like reaction using Fe3-xMnxO4-MKSF composite catalyst for degradation of acid orange II dye
Authors: Alrozi R , Zubir N A , Amir N , Abdul Rahman N N A , Kamaruddin M A
Published: December 2019

The selection of a good catalyst support is crucial in contributing towards the enhancement catalytic activity of a catalyst. Therefore, in this study, the influence of montmorillonite KSF (MKSF) clay loading in relation with catalytic performance of the resultant composite catalyst has been investigated. The MKSF clay loading were varied at x = 20, 40, 60 and 80 wt%, respectively. Interestingly, Fe3-0.3Mn0.3O4-MKSF(40wt%) has shown greater catalytic performance up to 98% of acid orange II (AOII) dye removal in comparison to the Fe3-0.3Mn0.3O4 and Fe3O4 catalysts. The AOII degradation kinetic using Fe3-0.3Mn0.3O4-MKSF(40wt%) was fitted well with first-order reaction kinetic and the reaction rate increased in the order of Fe3O4>Fe3-0.3Mn0.3O4>Fe3-0.3Mn0.3O4-MKSF(40wt%). It also demonstrated in the work that Fe3-0.3Mn0.3O4-MKSF(40wt%) catalyst can be reused several times without affecting its efficiency. Thus, it can be suggested that MKSF clay as catalyst support played a significant role in enhancing the overall catalytic performance of Fe3-0.3Mn0.3O4 catalyst during the heterogeneous Fenton-line reaction as well as the degradation kinetics of the AOII solutions.
Experimental diagnostics of the flow downstream the gas turbine premixer using planar optical methods
Authors: Chikishev L M , Dulin V M , Lobasov A S , Sharaborin D K , Savitskii A G , Tsatiashvili V V , Nazukin V A
Published: December 2019

This paper reports on experimental study of the flow in a model combustion chamber using planar optical methods. The flow was organized by model GT-premixer produced by JSC “EUC-Aviadvigatel”, Perm, Russia. The measurements were carried out in a cold flow without combustion at elevated pressure of 2 atm and air flow rate up to 0.5 kg/s. Acetone vapor was seeded to the flow as a tracer of model fuel. The distributions of local concentration were measured using planar laser-induced fluorescence approach. To measure velocity fields by particle image velocimetry technique, water-glycerol particles were introduced to the air flow. Two series of experiments were accomplished for design and off-design conditions. The pressure drop at the GT-premixer was the same for these two cases. The results for off-design conditions show that fuel concentration distribution drastically depends on the scheme of fuel supply.
Generation of wake-induced thermal fluctuations past a heated bluff body
Authors: Hrebtov M Yu , Nebuchinov A S
Published: December 2019

We present the results of LES modelling and PIV experiment of heat exchange between a flow in a wake of a heated bluff body and an array of thin plates. The efficiency of thermal fluctuations generation was investigated with potential applications to waste heat storing by pyroelectric effect. The effect of periodic attachment of wake vortices to the plates was observed both numerically and experimentally. This effect intensifies local heat transfer from fluid to solid and can be used for the possible generation of coherent temperature fluctuations in the plates.
Kinematic characteristics investigation in a transparent swirler of a vortex tube with square cross-section
Authors: Kabardin I K , Gordienko MR , Yavorsky N I , Pravdina M Kh , Polyakova V I , Ezendeeva D P , Kakaulin S V , Meledin V G , Pavlov P A
Published: December 2019

The work is devoted to experimental investigation of the vortex effect in the Ranque-Hilsch tube using non-contact methods. The vortex tube, which consists of the slit-type swirler made as accelerating vortex chamber, a working channel with a square cross section, a radial diffuser at the hot outlet and a diaphragm at the cold one was used. For optical diagnostics, the vortex chamber (swirler) was equipped with optical windows. On the basis of measurements by the laser Doppler anemometry method, new experimental information about flow at the entrance of the Ranque-Hilsch vortex tube was obtained.
Experimental determination of turbulence models applicability limits for the fluid dynamic computation in rotary divergent flow
Authors: Kabardin I K , Yavorsky N I , Meledin V G , Pravdina M Kh , Gordienko M R , Ezendeeva D P , Kakaulin S V , Usov E V , Klimonov I A , Krotov S V , Kabardin A K , Sadbakov O Yu
Published: December 2019

Such fundamental scientific problem arises in much industrial application. The turbulent fluid dynamic characteristics were analyzed experimentally in a rotary-divergent flow. The laser Doppler anemometry was used for turbulent mass transfer diagnostics. The verification of numerical calculations by computational hydrodynamics has been carried out according to the results of experimental studies. Verification has shown that turbulent models describe the rotational-divergent flow well only until generation of flow gaps and formation of recirculation zones.
Simulation of transonic low-Reynolds jets using quasi-gas dynamics equations
Authors: Kraposhin M V , Epikhin A S , Elizarova T G , Vatutin K A
Published: December 2019

In this paper application of the OpenFOAM solver QGDFoam for numerical simulation of transonic viscous flows is considered. The developed solver, which implements regularized or quasi- gas dynamics (QGD) algorithms, is validated using the transonic low-Re jet flow case (Ma=0.9, Re=3600). The conducted numerical simulations allow the assessing applicability of the solver for modelling hydrodynamic instabilities and their interaction with transonic flow. Results of the numerical simulations are compared with experimental observations and Navier-Stokes-based code simulation. Results of the present study formulate a guideline for choosing (values of) QGD-algorithm tuning parameters.
Visualization of instability processes in pure thermal plume
Authors: Kuznetsov E A , Kolesnik E V , Khrapunov E F
Published: December 2019

In the paper, the results of physical and numerical simulation of a natural convective flow formed over a heated horizontal disk are presented. The main purpose of this study is to analyze the occurrence of various stable states of a free-convection plume depending on the temperature of the heated surface. The presented flow patterns make it possible to determine the critical value of the temperature factor at which a change of stable states is observed. The visualization data obtained in the framework of physical modeling are compared and supplemented with data on flow patterns obtained numerically. A mechanism for the formation of separate air masses (“puffs”), which destroy both the near-wall layer and the formed upward flow is proposed. It was found that the emerging soft bifurcation is characterized by a sharp increase in the amplitude of perturbations with a slight increase in the value of the temperature factor: initial fluctuations of the plume boundary lead to further disruption of the heat balance and formation of puffs.
MHD and heat transfer in downflow and upflow of a liquid metal in the vertical pipe applied to tokamak reactor blanket module
Authors: Razuvanov N G , Luchinkin N A , Sviridov V G , Sardov P A
Published: December 2019

The studies of hydrodynamics and heat transfer were carried out with the upflow and downflow of liquid metal in a vertical pipe with one-sided heating affected by a transverse magnetic field. The task simulates a liquid metal flow in a cooling system channel of a TOKAMAK type fusion reactor blanket. The experimental data on heat transfer provided by detailed probe measurements were obtained using mercury MHD facility.
Experimental determination of circular fin effectiveness
Authors: Sapozhnikov S Z , Mityakov V Yu , Gusakov A A , Seroshtanov V V , Subbotina V V
Published: December 2019

The flow and heat transfer at the surface of a single circular fin and a finned cylinder were investigated comprehensively. The technique was carried out by combining PIV (Particle Image Velocimetry), gradient heat flux measurement and thermometry. The experiments were performed for a hollow (isothermal) fin and a fin made of titanium alloy VT22. The fins with a height of 20 and 60 mm were alternately mounted on a hollow cylinder. The cylinder was heated by saturated water vapor at atmospheric pressure. The angling device allowed us to investigate both the cross and non-cross flows around the model. The yaw angle β was 5, 10 and 15°. Visualization of the flow and measurement of the heat flux per unit area was carried out separately and independently in the same experiment. The PIV results revealed the influence of the yaw angle and intercostal space on the flow between the fins. Gradient heat flux sensors made it possible to obtain a distribution of the heat flux per unit area. Then the local heat transfer coefficients were calculated using thermometry data. It was possible to determine experimentally the effectiveness of the circular fins. This approach opens up new opportunities for study of convective heat transfer at surfaces of various shapes and purposes.
Mechanism of counterflows and circulation cells in swirling flows
Authors: Shtern V N
Published: December 2019

This paper reviews counterflows, double counterflows, and circulation cells in swirling flows and argues that all these seeming paradoxical phenomena can be caused by a common swirl- decay mechanism (SDM). It is shown that SDM explains (a) the counterflow of water and oil in hydrocyclones, (b) the elongated counterflow of hot and cold air in vortex tubes, and (c) the double counterflow occurring in vortex combustion chambers. SDM also explains the development and disappearance of circulation cells, often referred to as vortex breakdown bubbles, in sealed cylindrical containers where the flow is driven by rotation of one end disk. In a few words, SDM is the following. The balance of the centrifugal force and the radial gradient of pressure in a fast- swirling flow results in that pressure at the rotation axis is smaller than pressure at the periphery. If swirl decays downstream, pressure grows along the axis. This axial gradient of pressure decelerates the near-axis flow and can reverse it thus developing a local or global counterflow. It is shown that SDM also works in two-fluid flows modeling vortex bioreactors.
Simulation of turbulent wakes in model wind farm with arbitrary location for wind turbines
Authors: Strijhak S V , Koshelev K B , Kryuchkova A S
Published: December 2019

Wind energy is an important part of renewable energy sources in the Russian Federation. A new modern wind farm with 28 wind turbines was built on the territory of the Russian Federation, in the Ulyanovsk region in 2017-2018. When designing and operating a wind farm, it is necessary to assess correctly the power of each individual wind turbine. In this paper we used the open SOWFA library based on OpenFOAM 2.4.0 and URANS approach with k-e model of turbulence. The Actuator Line Model for the calculation of the forces from the wind turbines was used in pisoFoamTurbine.ALM solver. To set the boundary conditions at the input, the Precursor method was used. The unstructured grids with different number of cells were built. As a result of the calculation for 14 simulators of wind turbines, the values of the power coefficients Cp and thrust coefficients Ct were also determined. The maximum Cp value was in agreement with the Bets-Zhukovsky law for an ideal wind turbine. The new numerical case with 28 wind turbines was prepared for future simulations. The calculations were performed on a cluster of the UNICFD web-laboratory of ISP RAS. Each calculation was performed on 48-72 cpu cores.
Combustion model of boron-air suspension
Authors: Moiseeva K M , Krainov A Yu
Published: December 2019

This paper presents a physico-mathematical combustion model of the boron-air suspension. The oxidation mechanism and combustion of boron particles are based on the study by King M. K. The physico-mathematical formulation of the problem implies the approaches by R.I. Nigmatulin for the mechanics of two-phase reactive media. The paper provides numerical investigation on the effect of mass concentration and boron particle size on the apparent and normal combustion front velocity of the boron-air suspension.
Influence of soluble surfactant on wave evolution on falling liquid films
Authors: Bobylev A V , Guzanov V V , Kvon A Z , Kharlamov S M
Published: December 2019

We have investigated the effect of soluble surfactant Triton X-100 on the initial development of waves on vertically falling liquid films. Field method of laser induced fluorescence was used to obtain instantaneous wave patterns forming at different concentrations of the surfactant. These concentrations were chosen on the basis of simple consideration that most pronounced influence of the surfactant on the wave characteristics should be observed when relaxation time of surface tension (dependent on surfactant concentration) is comparable with characteristic time of wavy motion. At low and moderate surfactant concentrations damping of waves is observed, which coincides with the results of other authors. At large surfactant concentration the waves start to grow again, but without initial stage of two dimensional wave development typical of pure liquids. The absence of this initial stage is due to the formation of rivulets on the free surface of films in the presence of the surfactant. The influence of the surfactant concentration on characteristics of rivulets and waves is described.
Energy characteristics of a radiating thin layer of bubbles in a liquid
Authors: Borodulin V Yu , Ogorodnikov I A
Published: December 2019

The radiation of a thin bubble layer in an infinite liquid excited by a single wave of large amplitude is studied. It is shown that, after excitation, the layer emits a strong nonlinear wave in both directions. The radiation of the layer becomes close to sinusoidal with one line in the spectrum at large times. It is shown that in the nonlinear phase of the sound wave radiation, the time variation of the bubble energy in the layer is characterized by a stepwise dependence.
The propagation of temperature pulsations along the free surface of a liquid layer from a linear heat source
Authors: Berdnikov V S , Grishkov V A , Markov V A
Published: December 2019

The evolution of the temperature field on the free surface of a fluid near a periodically heated wire is experimentally investigated. The wire was heated by rectangular current pulses with specified duration and pulse repetition period. The data on the spatial characteristics of thermal waves and the propagation velocity of a thermal wave are presented. Using digital video of the visualized fluid flow, the structure of the unsteady convective fluid flow was studied
On the modes of cuttings transport in an inclined annular channel
Authors: Ignatenko Ya , Gavrilov A , Bocharov O , May R
Published: December 2019

The paper presents the results of the simulation of cuttings transport (solid spherical particles) by water through a long annular axisymmetric inclined channel. At the inlet uniform distribution of particles and fluid velocity was set. Inclination angle varied from 0 to 90 degrees. Modes of stationary and moving dunes and their transition into wave-shaped and stationary sediment were observed. Moving dunes could oscillate laterally and did not form a crest that occupied the entire width of the channel. In this case, dense sediment formed an S-shaped path, moving along the stream. Despite the general downstream movement of the S-shaped track (dune), a downward flow might occur in the low area with high concentration. Five basic flow regimes were identified: constant sediment, moving wave-like sediment, separated stationary dunes, S-shaped sediment and homogeneous flow. The basic flow pattern could be complicated by lateral motion and backward flow in a region of high concentration. A variant of the flow pattern map is suggested.
Change in wave characteristics during the transition from gravitational to shear flow of gas-sheared liquid films
Authors: Isaenkov S V , Cherdantsev M V , Cherdantsev A V , Markovich D M
Published: December 2019

The evolution of thin liquid films sheared by a co-current gas flow in a vertical cylindrical channel with an internal diameter of 11.7 mm was studied using a high-speed implementation of the laser-induced fluorescence method. The main purpose of the work was to study the characteristics of the waves during the transition from the gravitational to the shear flow regime. The effect of gas velocity, liquid Reynolds number, and liquid viscosity on wave characteristics has been studied.
Stochastic simulation of transport processes in liquids
Authors: Rudyak V Ya , Lezhnev E V
Published: December 2019

The subject of this paper is molecular stochastic modeling the transport processes in liquids. The proposed method and the corresponding algorithm are an alternative to the molecular dynamics method. However, unlike the latter the system of Newtonian equations is not solved for modeling the phase trajectories of the system studied. The phase trajectories of the molecular system are simulated stochastically. For this purpose, the database of the intermolecular forces acting on each molecule of the system during the considered time interval has been created. The distribution function of these forces has been built. It was shown that this distribution function can be approximated by certain analytic function. The dependency of the parameters of this function on the liquid temperature and parameters of the intermolecular interaction potential (the Lennard-Jones interaction potential is used) is determined. Using this distribution function the force acting on each molecule at given time is determined. After that the coordinates and velocity of all molecules of the system are calculated. As a result, the full information about the phase variables of the molecular system is obtained. All macroscopic characteristics of the system (temperature, pressure, transport coefficients etc.) are calculated by means of the methods of nonequilibrium statistical mechanics. The transport coefficients are calculated using fluctuation-dissipation theorems that relate transport coefficients to the evolution of the corresponding correlation functions. The algorithm was tested on the calculation of the viscosity of several simple liquids.
Individual bubbles moving in an inclined flat channel
Authors: Randin V V , Chinak A V
Published: December 2019

The results of an experimental study of single bubble movement in an upward bubble flow in an inclined flat channel are presented. The measurements were carried out for a liquid Reynolds numbers 2000÷22700 and for channel inclination angles 0÷90. It is shown that in a gas-liquid flow the channel inclination angle has a significant effect on the flow characteristics. The data obtained in the experiments show that bubble rise velocity is lower than that in a large volume of a quiescent liquid and is affected channel inclination angle. With an increase in the Reynolds number, the influence of the channel inclination angle on the two-phase flow decreases.
Particle Reynolds stress model for wall turbulence with inertial particle clustering
Authors: Sikovsky D Ph
Published: December 2019

The modification of Zaichik particle Reynolds stress transport model for turbulent particle-laden flows is developed taking into account the clustering phenomenon of inertial particles. The main novelty is the new boundary condition for the particle Reynolds stress, which is posed at some distance from the wall in the viscous sublayer and is consistent with the power-law singularity of particle concentration at the wall. The modified model avoids the spurious bifurcation of the solution, which observed for non-modified Zaichik model with the near-equilibrium wall boundary condition.
Evaporation of non-ideal binary solution drops
Authors: Borodulin V Yu , Nizovtsev M I , Sterlyagov A N
Published: December 2019

The study of the evaporation process of multicomponent liquid droplets was carried out in the work. In the simulation and experiments, an aqueous solution of ethanol of various concentrations, which is a binary non-ideal mixture with known physicochemical properties, was used as a mixture. The deviation of the solution properties from ideal was taken into account using the generalized dependence of the pressure of vapor components saturated above the solution on their concentration in the solution. Using an example of an aqueous ethanol solution, a deviation of the change in the diameter of the droplets from the “law d2” was shown, which is associated with a two-speed evaporation mode. During evaporation at a low concentration of ethanol, the temperature of the droplet was close to the temperature of adiabatic evaporation of water; at a high concentration of ethanol, it was close to the temperature of adiabatic evaporation of ethanol. Comparison of the results of the simulation with experiment showed satisfactory agreement.
Chaos under interface oscillations during boiling and sea surface agitation
Authors: Kuzma-Kichta Yu A , Bondur V G
Published: December 2019

Results of investigation of the phase interface fluctuations at film and bubble boiling and sea surface agitation are presented. The vapor film thickness and vapor bubble growing on the wall were determined with the aid of laser diagnostics. Oscillations of a growing vapor bubble and simultaneous pressure oscillations in liquid were detected using optical (laser) and acoustic diagnostics. For the very first time volume and shape oscillations of a vapor bubble growing on a wall were determined. An approached model of volume oscillations of a vapor bubble, growing on a heat transfer surface is presented basing on experimental data. The system of model equations and bubble dynamics were presented considered, accounting simultaneous evaporation and condensation at the interface. It has been found that the growth of a vapor bubble is accompanied by its volume oscillations, which become chaotic under certain circumstances.
Dynamics of heat transfer at the coalition of the drops on a horizontal heated surface
Authors: Ponomarenko T G , Cheverda V V
Published: December 2019

An experimental study was carried out to investigate heat transfer during the coalition of two drops of the same volume. The falling of a water drop to other drop sitting on a heated horizontal foil made of constantan with a thickness of 25 μm from a distance of 10 mm was recorded with a high-speed video camera. An infrared scanner was used to measure the temperature field on the surface of the foil. Measurements taken with the infrared scanner will be used to determine the heat flux density in the region of the dynamic contact wetting line at the coalition of drops.
The regenerative heat exchanger with periodic veering of the flow
Authors: Aktershev S P , Mezentsev I V , Mezentseva N N
Published: December 2019

In the given work numerical simulating of the regenerative heat exchanger with a cyclic flow veering is executed in application to the ventilation system. The heat exchanger contains the grained medium consisting of solid spherical elements, storing heat. During a half cycle the entering cold air passes through the grained medium, heating it up to the room temperature. Then the air flow direction is reversed and during another half cycle the exhaust warm air refunds heat to the grained medium. Unlike the former researches, the case of low thermal diffusivity of spherical elements, when heat transfer is determined by the properties of a grained medium, is investigated. The mathematical model describing a cyclic mode of heat exchanger operation is developed. The basic criteria determining heat transfer and their influence on heat regeneration efficiency are revealed.
Simulation of orthogonal rotors with dynamic pitching blades
Authors: Dekterev D A , Dekterev Ar A , Lobasov A S , Platonov D V , Sentyabov A V , Dekterev A A
Published: December 2019

An adaptation of the mathematical model for the investigation of the parameters of orthogonal wind turbine has been performed. The simulation of Darrieus H-type rotor operating modes was performed and compared with experimental data. A kinematic scheme with dynamic blades was used for optimal tip-speed ratio. The results of numerical simulation with different deflection angles at fixed tip-speed ratio 1.6 showed that maximum rotor efficiency is reached for a blade pitch angle equal to 8 degrees. One can see that the use of the kinematic scheme, which allows changing the pitch angle of blades, leads to an increase in the efficiency of the rotor in the range from 12 to 50% (depending on the tip-speed ratio).
Simulation of heat and mass transfer in a shaft plasma furnace for the processing of municipal solid waste
Authors: Anshakov A S , Domarov P V , Faleev V A
Published: December 2019

A mathematical model of the process of heat and mass transfer in two penetrating media (gas stream and waste mixture) during plasma gasification of organic waste is presented in the article. The model takes into account many parameters: the total pressure of the vapor-gas mixture, partial pressure, humidity of the waste, etc. The effect of humidity during heat and mass transfer in the reaction zone of a mine electric furnace on the temperature distribution in the waste charge and the gas phase is shown.
Method of research on heat exchange for parallel plates with low thermal conductivity in short-time processes
Authors: Kirsanov Yu A , Makarushkin D V , Yudakhin A E , Kirsanov A Yu
Published: December 2019

Temperature of coolant was measured at the input and output of an alternating regenerator. Additionally, the temperature was measured both at several points on the surface of the parallel plates and along their geometrical axis. The package of the parallel plates was used as a nozzle of the regenerator. The method of determining heat transfer coefficients was described for the side and butt end surfaces of the plates in short-time processes. The mathematical models were created for the following two non-stationary processes. The first process is convective energy transfer in heat carrier flows. The second one is the process of thermal conductivity of two-dimensional body (plate) washed cyclically by cold and hot heat carrier flows. The coefficients of cyclic heat exchange with the cold and hot heat carrier flows were obtained for the side and butt end surfaces of the plates in short-time processes.
Optimization of the cyclic pumping of high pour point and high viscosity oil mixtures through main oil pipelines
Authors: Bekibayev T T , Zhapbasbayev U K , Ramazanova G I , Makhmotov E S
Published: December 2019

This paper presents the optimization results of the cyclic pumping of batches of high-pour-point and high-viscosity oil mixtures at the Uzen-Atyrau section of the Uzen-Atyrau-Samara main pipeline, taking into account on-route heating, boosting and pumping-out. The optimization criterion was the minimum total cost of power consumption by the pumping units and the preheaters.
Effect of hydrogen concentration on CVD synthesis of graphene
Authors: Kostogrud I A , Boyko E V , Smovzh D V
Published: December 2019

The paper is devoted to the study of AP-CVD synthesis of graphene on a copper substrate. In this work, the effect of hydrogen concentration in the synthesis gas mixture on the growth of a graphene coating is studied experimentally. Two series of experiments with methane concentrations of 0.02% and 0.05% are presented. It is shown that a change in concentration of hydrogen has a nonmonotonic effect on the degree of substrate covering with graphene. This indicates that hydrogen is involved in several competing processes. One of these processes is stabilization of the edges of growing graphene domains. Another is etching of the forming graphene structures and reduction of hydrocarbon radicals on the copper substrate surface and in the bulk. It is shown that an increase in methane concentration leads to an increase in the rate of graphene crystal growth. To preserve the kinetics of graphene domain growth, it is necessary to reduce the H2/CH4 coefficient in the working mixture.
Composite tin/carbon material synthesis by arc discharge at different helium pressures
Authors: Kozlachkov D V , Zaikovskii A V
Published: December 2019

Composite Sn + C electrodes were sputtered using an electric arc method. As a result, materials representing spherical tin nanoparticles packed in a carbon matrix were synthesized. The carbon matrix reliably separates the nanoparticles, preventing them from contacting and coagulating, which preserves their size. The structure of the material was studied in detail by transmission electron microscopy. The sizes of tin nanoparticles were described by a log-normal distribution, and the average size depended on the pressure of the buffer gas. The carbon structure was studied by Raman spectroscopy. It is established that tin and carbon structures are related to each other, and the processes of condensation of tin vapor and agglomeration of the carbon structure affect each other.
Measurement of silicon suboxide films thickness synthesized by the gas-jet electron beam plasma chemical vapor deposition method
Authors: Merkulova I E
Published: December 2019

The amorphous silicon suboxide thin films were synthesized by the gas-jet electron beam plasma chemical vapor deposition method. The thickness of the thin films was obtained using a cross-section SEM image (destructive) and an analysis of interference effects in the IR transmission spectra (non-destructive). The film thicknesses obtained by the cross-section SEM images were about 600 nm for all samples. An approximation of the silicon suboxide film thickness was made using a Gaussian distribution, which showed good agreement with the experimental values. The thickness obtained from the analysis of the IR transmission spectra increases from 400 nm to 500 nm with increasing Gmix. It was found that the oxygen concentration of the thin films decreases from 45 to 22% with an increase in Gmix.
Silicon nanowhisker formation during SiO2 evaporation by arc discharge
Authors: Zaikovskii A V
Published: December 2019

Nanoscale silicon is interesting in various areas, including electronics, photovoltaics, solar and Li-ion energetics. This work describes processes of electric arc sputtering of SiO2 in a graphite electrode in a helium medium, leading to formation of silicon nanowhiskers. A fan- shaped turbulent jet of vapors of the sprayed electrode flowing from the interelectrode space, resulting in formation of areas with different component compositions and temperatures, is considered. Interaction of SiO and Si vapors leads to the formation of the silicon nanowhisker structure.
Low-parametric equation for calculating the viscosity coefficient of sulfur hexafluoride
Authors: Kaplun A B , Meshalkin A B , Dutova O S
Published: December 2019

A low-parametric equation for calculating the SFe viscosity coefficient in liquid, gaseous, and fluid states was derived using previously obtained unambiguous dependence of the “excess” viscosity of liquids and dense gases on the density of internal energy. The equation describes the viscosity of sulfur hexafluoride at the temperatures from 230 K to 650 K and pressures of up to 50 MPa in the limits of experimental error.
The linear thermal expansion coefficient of iron in the temperature range of 130–1180 K
Authors: Kozlovskii Yu M , Stankus S V
Published: December 2019

The results of a dilatometric study of the thermal coefficient of linear expansion of polycrystalline iron in the temperature range of 130–1180°K are presented. The measurements were made with an error of 3%. Temperature dependences were obtained and reference tables of the recommended values of volume properties were calculated. The region of the magnetic phase transition was studied in detail, and the critical indices of thermal expansion at the Curie point were determined.
Phonon density of states and thermodynamic properties of Eu2(C11H19O2)6
Authors: Musikhin A E , Bespyatov M A
Published: December 2019

In the work, the phonon density of states of europium dipivaloylmethanate was calculated based on the experimental low-temperature heat capacity, and basic characteristic temperatures related to the moments of the g(ω) were obtained. The molar thermodynamic functions of Eu2(C11H19O2)6 at constant volume up to the melting point of 464 K were calculated: heat capacity, entropy, internal energy, and Helmholtz energy. The zero-point energy was determined, and total internal energy was obtained. Accuracy of the obtained results was estimated. The approach used to obtain the properties of Eu2(C11H19O2)6 is general, it can be used to study a wide range of solids.
Vapor thermal conductivity of R-125/R-134a (84.6/15.4) mixture
Authors: Raschektaeva E P , Stankus S V , Verba O I
Published: December 2019

The vapors thermal conductivity of binary mixture R-125/R134a (84.6/15.4) was measured with a coaxial cylinders method in the temperature range of 305–412 K and the pressure range of 0.1–1.7 MPa. The thermal conductivity as a function of pressure and temperature was considered. The correlations for thermal conductivity on dew line and in ideal gas state are presented.
Heat transfer coefficients of praseodymium in condensed state
Authors: Samoshkin D A , Agazhanov A Sh , Stankus S V
Published: December 2019

The thermal diffusivity and the thermal conductivity coefficients of praseodymium have been investigated by the laser flash technique with an error of 3–6% in the temperature range from 295 to 1625 K of the solid and liquid states, including the regions of phase transitions. Comparison of measurement results with the available literature data was carried out. The fitting equations and the table of reference data on the heat transfer coefficients of praseodymium for scientific and practical use have been developed.
Vapor pressure, density, and speed of sound of the R134a-R227ea refrigerants in the vapor phase
Authors: Komarov S G , Stankus S V
Published: December 2019

The pressure on the dew line and density of the gas-phase 69.2 wt.% R134a / 30.8wt.% R227ea refrigerant were investigated using a constant volume piezometer in the temperature range from 293 to 373 K and at pressures from 0.45 to 3.1 MPa. The speed of sound of the 70.1 wt.% R134a / 29.9 wt.% R227ea mixture (323-373 K, 1.2-1.5 MPa) was also measured using an ultrasonic interferometer. The measurement errors of the temperature, pressure, density, and speed of sound were ±20 mK, ±4 kPa, ± (0.15–0.25)%, and ± (0.2–0.3)%, respectively. Approximation dependences of the studied properties were obtained and their errors were estimated. The obtained results were compared with the calculations using the REFPROP program.
Numerical modelling of a two-channel heat and mass exchanger
Authors: Gorbachev M , Terekhov V
Published: December 2019

This work is devoted to the study of heat and mass transfer apparatus of indirect- evaporative type. This device consists of two channels, in one of which the processes of heat and mass transfer occur. This scheme is known in the literature as the By-pass scheme. Numerical studies of laminar flow and heat and mass transfer are carried out with variations in the input parameters (Reynolds number Re=100, temperature T
0 = 26 ÷ 32 °C and relative humidity φ0 = 40 ÷ 70 %). The resulting cooling effect in such a heat and mass transfer apparatus can be quite high and comparable with traditional air conditioning schemes, including steam-compression refrigeration machines.
The heat balance model of walling constructions
Authors: Kaledin V O , Galdin D A , Viachkin E S , Gileva A E , Viachkina E A , Ulyanov A D
Published: December 2019

The inverse problem of identifying the heat loss model in a building through building envelopes is considered. The linear equations of heat balance in heated rooms are used. These equations take into account the thermal conductivity through the walls and the glazing of the openings, two-way convective heat exchange of the room air with heating devices and enclosing structures, and convective heat dissipation into the environment. The results of model identification based on experimental measurements of temperature fields in the building envelope are presented.
Model of heat and mass transfer in the heating system pipe
Authors: Kaledin V O , Viachkin E S , Gileva A E , Viachkina E A , Galgin D A , Ulyanov A D
Published: December 2019

The paper considers a mathematical model of the temperature distribution over the heating pipe to estimate the actual parameters of the heating system based on the results of temperature measurements. An example of solving the problem of actual flow rate identifying of the coolant in the risers, the temperature at the entrance to each riser and the shunt coefficients of the radiators of the heating system of the building is given. Identification results are used to diagnose the condition of the heating system.
Natural Dyes from Secang (Biancaea sappan) Wood in Sutera
Authors: Kurniati  , Abu Asiani , Irmayanti  , Aisyah
Published: December 2019

Colour variations are needed to support the textile industry development to increase product attractiveness. Textile dyes can come from natural and synthetic materials. Natural dyes can be the best solution to replace synthetic which is harmful to the environment. One of the natural dyes is a secang plant. This study aims to determine the absorption of silk fabrics on the secang wood colour using fixator. The research procedure consisted of a literature review, observation, data verification, experimentation and processing using descriptive statistical analysis. The results showed that the ability to absorb silk fabric against the secang wood colour using fixators produced a very sharp and bright colour and very flat on the fabric surface. The alum fixator produces a Dark Red colour, quicklime fixator is Maroon which is included in hot colours on colour circle, while tunjung fixator is Black from other colour clumps.
The effect of pollinator insect visitation on flower development and productivity of chilli plant
Authors: Aminatun T , Budiwati  , Sugiyarto L , Setyawan S A , Desiliani A
Published: December 2019

This research aimed to find out; (1) the pollinator insect diversity of chili plant; and (2) the effect of pollinator insect visitation on flower development and productivity of chili plant. This experimental study was designed with a factorial completely randomized design. The independent variable was visitation of pollinator insect on plant, while the dependent variables were pollinator insect diversity, flower development, and productivity of chili plant. Each treatment consisted of 5 replicating plots, and each plot contained 4 potted plants. Flower development observation was carried out as long as the chili plant flowering. As supporting data were the frequency and longevity of pollinator visiting. The results showed pollinator insects on chili plants were Trigona, Apis, Lasioglossum, and Camponotus. The highest frequency of visitation were Trigona and Camponotus, while the highest longevity was Camponotus. The inhibitory treatment of pollinator insect visitation caused the plant began to flower more slowly and the flower bloomed last longer. The plant was also harvested 2 months slower, and the average number and weight of fruit per plant tended to be lower.
Development of Non-QWERTY Balinese Script Keyboard Through Tamiang Keyboard Optimization With Letter Frequency Concept
Authors: Pradnyana G A , Setiawan G A , Wirawan I M A
Published: December 2019

Aksara Bali (Balinese Script) is a traditional Indonesian script that developed in Bali, and also known as Hanacaraka. Tamiang Keyboard is a non-qwerty keyboard for typing Balinese script. This keyboard was developed using character extraction methods from the Balinese language dataset by rewriting Balinese script into Latin or Roman characters. The advantage of using the Tamiang keyboard is that users can type Balinese script like writing or “nyurat” Balinese script without various rules such as when using script fonts. Tamiang Keyboard development focuses more on the typing mechanism and placement of Balinese letters on a keyboard button. However, the placement of letters on the keyboard is only based on the separation of letters that often appear on the datasets. This process has an impact on the effectiveness and convenience of users in typing Balinese language using Tamiang Keyboard. In this study, a new Balinese script keyboard was developed by applying the letter frequency concept to optimize Tamiang Keyboard. Letter frequency calculations are used to analyze aspects of home row usage, hand load analysis, and analysis of finger loads when typing balinese language with Tamiang Keyboard. The analysis of these three aspects is used for re-mapping the letters on the keyboard.
The Development Of Physical And Sport Education Learning Model By Using Small Games
Authors: Bukhari K , Efendi Z. M , Jama J
Published: December 2019

The purpose of this research is to (1) develop a in learning Physical and Sport Education learning model through small games in increasing a disciplined and confident attitude that was practical and effective of Volley Ball state vocational high school Bengkulu and (2) knowing the validity and reliability of the learning model, so that it could be used to measure students’ discipline and self-confidence. The type of this research is a research and development that followed up with the development of education. Procedure development on Physical Education and Sports Skills, Skills model through small games in instilling based on the ADDIE model, consisting of five stages, namely analysis, design, development, implementation, and evaluation. The location of these product trials conducted among students vocational high school Bengkulu. The instruments used to collect the data were questionnaire and evaluation sheet. Data analysis techniques of this research use descriptive analysis technique in the form of the percentage. Subject of this study was class X (34 students). Data were obtained by observation techniques and analyzed by descriptive analysis. The result of this research shown that learning model develop a in learning Physical Education and Sports Skills model through small games in instilling a disciplined and confident attitude that was practical and effective to enhance the effectiveness of learning organized by teachers and attended by students sampled in this research. The results of this study use affective assessment by observation, namely variable of students in instilling discipline and confident in learning phsysical education and sports skills, with the acquisition of a good average score then the highest score of 76 % who got a very good criteria and criteria less than 0 % did not exist.
Augmented Reality-Based Instructional Media for Electrical Power Protection Learning
Authors: Maryadi Totok Heru Tri , Sukisno Toto , Chandra N. Ariadie , Atmoko A. Widi
Published: December 2019

Augmented reality is a technology that combines two-dimensional and/or three-dimensional virtual objects into a real three-dimensional environment and projects those virtual objects in real time. This study was aimed at discussing (1) the development of an instructional media for power system protection learning, especially the fuse cut out, using augmented reality, (2) the appropriateness of the developed media as evaluated by both material and media experts, and (3) the users’ responses toward the developed media. This media was developed using the waterfall model proposed by Pressman, consisting of four main stages: analyzing, designing, coding, and testing. The performance test proved that this media functioned properly (100%). This media was categorized as “highly appropriate” in terms of the materials presented as evaluated by the material experts with a mean score of 96.5 out of 112. Meanwhile, the media was “appropriate” as evaluated by the media experts with a mean score of 68 out of 84. For the end users of this media, 75% of them perceived this media as “highly appropriate”, while the rest considered it as “appropriate”.
Development of e-learning content with H5P and iSpring features
Authors: Amali L N , Kadir N T , Latief M
Published: December 2019

E-learning is currently a fast-developing learning method. Interactive multimedia technology, which combines computer technology, video, and audio, is needed to support this e-learning system. The objective of this study is to develop e-learning content based on interactive multimedia to support the effectiveness of a learning system. SDLC (System Development Life Cycle) method with the waterfall model was used in this study. The output of this study is developed e-learning with additional content that utilizes interactive multimedia features, H5P, and iSpring. Through this system, the teacher can create content improvement in the learning model. The system provides various learning sources and activities to support a more interactive teaching and learning process. This e-learning can ease students in understanding the materials and motivates them in learning through this multimedia learning media.
Development of Interactive Learning Media based on Android Education Geography
Authors: Arliza Rika , Yani Ahmad , Setiawan Iwan
Published: December 2019

This research is a type of product development that aims to determine the feasibility of developing interactive learning media products based on Android. The research method used is the design of the development model used in this study is the adaptation of the Luther model. The results of this study are: (1) Android-based interactive learning media applications on national cultural material and global interactions are arranged by getting input from validators (2) the results of the feasibility of the percentage of android-based interactive learning media by media experts are seen based on the aspects of animation, video aspects, video aspects, packaging aspects, packaging aspects, packaging aspects and aspects of use.