bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kindergartens in Northern Norway as semiotic landscapes
Authors: Pesch Anja Maria , Dardanou Maria , Sollid Hilde 
Published: April 2021

Abstract
Educational institutions have a responsibility to ensure that all children receive care and equal possibilities for development, independent of their linguistic and cultural background. However, there is little knowledge about how kindergartens ensure a welcoming and inspiring place for both transnational migrants, Indigenous children, and children from the majority population. Through a semiotic landscape analysis from two kindergartens in Northern Norway, this article contributes to this knowledge gap. Our starting point is that educational spaces are social, cultural, and political places. Applying a Bakhtinian perspective on semiotic landscapes as dialogues, the analysis focuses on two discourses. The first concerns diversity as an individual or shared value, and the second concerns balancing the ordinary and the exotic. We find that diversity related to transnational migration seems to be more integrated into the semiotic landscape, while the minoritised Indigenous Sámi people is stereotypically represented in kindergartens.
Waste to worth: fruit wastes and by-products as animal feed.
Authors: Manju Wadhwa Manju Wadhwa , Bakshi M. P. S. , Makkar H. P. S. 
Published: April 2021

Abstract
The increasing trend future consumption of animal products will give rise to a huge demand of animal feed. Meeting this demand will be a challenge, given the scarcity of natural resources such as land and water. Currently approximately 1.3 billion tonnes of food is lost and wasted annually, and fruit and vegetables (FV) form a substantial part of this loss. Use of FV loss and waste, as animal feed, can contribute to meeting the feed deficiency existing in most developing countries. Also their use as animal feed will bring them back into the human food chain. Simultaneously it will help mitigating environmental problems that arise due to decomposition of such wastes in the environment. This review, first in a series, discusses options and challenges in using fruit wastes and by-products as animal feed. The fruits discussed are amla, apple, apricot, banana, citrus and raspberry, among many others. The nutritional value, conservation methods, feeding management and guidance on the levels at which these unconventional feed resources can be used in the diets of farm animal species are presented. Some of the major constraints in the use of fruit wastes and by-products are the presence of pesticides, pesticide residues, mycotoxins, heavy metals, furans and dioxins. There is a need to regularly monitor such contaminants in these feed resources. Equally important is to conduct risk assessment given the presence of these contaminants in the animal diets. A concerted research and commercial efforts are needed to realize the full potential of such wastes and by-products for the animal agriculture.
SVM Approach for Forecasting International Tourism Arrival In East Java
Authors: Purnaningrum Evita , Athoillah Muhammad 
Published: April 2021

AbstractThe maneuver of international tourists visiting Indonesia, especially the East Java area, in positive correlation with time. In accordance with the government’s work program to increase GDP from the tourism sector. However, the condition necessary to be supported by the existence of feasibility and adequate tourism services. Facility improvements certainly require a projection of international tourist arrivals visiting East Java. SVM is a machine learning method that has shown excellent performance in predicting time series. In addition, analysis results have shown that SVM had able to predict foreign tourist visits with a high degree of accuracy. Therefore, this research can be used as a support for tourism facility procurement policies, especially in East Java.
Numerical study of disturbances generated by localized impulse action in a flat-plate boundary layer at Mach 2
Authors: Khaibullina S R , Yatskikh A A , Semenov A N , Kocharin V L 
Published: April 2021

Abstract
The work is devoted to the numerical simulation of the excitation and development of localized disturbances in the supersonic boundary layer of a plate with a sharp leading edge at a Mach number of 2 in a two-dimensional formulation. Artificial disturbances are generated with the help of localized in time and space by changing the boundary conditions to the velocity component normal to the surface. The studies for two intensities of the impulse action were carried out. It was found that with an increase in the intensity of the action on the boundary layer, the amplitude of the generated disturbances increases. The development of disturbances of various amplitudes is similar. The ratio of the level of total temperature pulsations to the level of mass flow pulsations was estimated for the investigated disturbances. It was found that at small distances from the source of disturbances, this ratio increases downstream, at the same time in the far field, it reaches a constant value.
The study of heat transfer during condensation on inclined pipes by gradient heatmetry
Authors: Mityakov V Yu , Sapozhnikov S Z , Zainullina E R , Babich A Yu 
Published: April 2021

Abstract
The paper presents results of studying of heat transfer during condensation on the outer surface of inclined pipe by using gradient heatmetry. The proposed approach made it possible to estimate distribution of local heat flux per unit area in several sections along the pipe’s length. Combination of gradient heatmetry and thermometry allows us to show dependence of heat transfer coefficient from the angle of pipe inclination. Under experimental conditions the maximal average heat transfer coefficient, α = 6.94 kW/(m2 • K), was observed when the pipe was tilted at the angle of ψ = 20° from vertical. The relative uncertainty of measured heat flux per unit area was of 7.5 %, and for heat transfer coefficient it does not exceed the level of 8.4%. The use of gradient heatmetry in this study provides us information about films thickness distribution over the pipe surface without optical visualization, which is especially important in experiments at industrial heat exchangers.
Experimental investigation of vortex core properties of a finite span wing and an isolated rotor model
Authors: Stepanov R P , Kusyumov A A , Pakhov V V , Mikhailov S A , Tarasov N N , Mirgazov R M 
Published: April 2021

Abstract
This work outlines results of an experimental investigation of vortex core properties of a finite span wing and a helicopter rotor model operating at hover mode. Experimental data was obtained using Stereo-PIV in T1-K wind tunnel at KNRTU-KAI named after A.N. Tupolev. An empirically derived formula is proposed, allowing to estimate the dependence of the vortex core size from the threshold Q-value. The wing tip vortices were measured for different angles of attack. The tip vortices from the rotor blades were measured at two collective pitch angles. The results indicate that the obtained empirical equation can be used to estimate the impact of the lowest threshold Q-value selection on the size of the vortex core, which facilitates a more objective approach compared to known methods, when used to eliminate non-essential vortical regions.
Effect of wood structure geometry during firebrand generation in laboratory scale and semi-field experiments
Authors: Kasymov D P , Agafontsev M V , Tarakanova V A , Loboda E L , Martynov P S , Orlov K E , Reyno V V 
Published: April 2021

Abstract
As the set of experiments result, statistically substantiated data were obtained on the laws of ignition of a model angular structure under conditions of a point source of heat exposure. The use of IR diagnostics made it possible to control the thermal picture in the experimental area, as well as to capture areas of the highest and lowest heating. In the Large Aerosol Chamber of IAO SB RAS, preliminary experiments were carried out on a “firebrand shower” model exposure, which is naturally occurring firebrands (flaming or glowing embers) with some types of construction materials (chipboards). The exposure of the samples to firebrands stream was provided using a firebrand generator of own original design. It was experimentally confirmed that particle size plays a significant role in the ignition of a building structure. If the characteristic particle size, which can be defined as the ratio of its volume to the surface area in contact with the wood, is less than a certain characteristic value, then the ignition mode with a sharp temperature maximum near the phase interface is not fulfilled. This can be explained by the prevailing heat removal into the external environment in comparison with the amount of heat coming from a heat gun and resulting from chemical reactions.
Dependence of the surfactant solutions surface tension on the concentration and on the temperature
Authors: Sibiryakov N 
Published: April 2021

Abstract
This paper presents the dependence of the surface tension on the surfactant concentration and on the temperature for anionic cetyltrimethylammonium bromide (CTAB) with a concentration of 1 mmol/L and two-ionic lauryl hydroxysultaine (LHS) with a concentration of 2.8 mmol/L. At a low concentration of the surfactant, the surface tension drops sharply at a certain temperature, and at a high concentration it changes slightly, much slower than surface tension of the pure water. Surface tension rapidly drops because micelles in the bulk become unstable and surfactant particles relocate to the interface.
Verification of the method for determining heat fluxes and heat loses in experiments with a shear-driving liquid film
Authors: Tkachenko E M , Belosludtsev V V 
Published: April 2021

Abstract
The cooling of microelectronic equipment is currently one of the most difficult problems of thermal physics. To achieve high heat fluxes and reduce the volume of liquid used, the technological solution looks especially promising, where heat is transferred from the fuel element to a thin, intensely evaporating film of liquid moving under the action of friction of a forced gas flow in a mini-or micro-channel. In recent works, the study of heat losses and determination of the true heat flux in experiments with an intensely evaporating liquid film moving under the action of a gas flow in a mini-channel was carried out. In this paper, the task is to verify the method for determining heat losses. Heat transfer in the convective flow regime is investigated. The experimental and calculated Nusselt numbers in convection experiments with complete channel flooding are in good agreement. In addition, the experimental and calculated Nusselt numbers for film flows are in good agreement. This indicates the correctness of the method for determining heat flux and heat losses in previous studies.
Optical properties of nanocolumnar silver films obtained by pulsed laser deposition
Authors: Starinskiy S V , Rodionov A A , Shukhov Yu G , Bulgakov A V 
Published: April 2021

Abstract
Nanostructured silver films are considered as an important material for biomedical applications due to their unique optical and antiviral/bactericidal properties. The character of silver films depends on morphology, structure and thicknesses, which are determined by the method and regime of synthesis. In present work we show that a relative thick silver film obtained by pulsed laser deposition has an interesting porous nanocolumnar morphology. Optical properties of the produced samples are investigated. An empirical dependence for determining the thickness of the silver coating from the optical transmission spectra is proposed.
Numerical simulation of crystallization on a stationary and rotating cooled disk
Authors: Kislitsyn S A , Berdnikov V S 
Published: April 2021

Abstract
The process of crystallization of silicon melt on a monotonically cooled disk located on the free surface of the melt is studied numerically. The influence of thermogravitational, thermal gravitational-capillary and mixed convection on the shape of the crystal-melt interface is investigated. In mixed convection modes, the speed of uniform rotation of the disk is set. The calculations were carried out in an axisymmetric formulation of problems by the finite element method using an adaptive triangular mesh and taking into account the latent heat.
The features of cavitation flow around a cylinder with a very low aspect ratio
Authors: Skripkn S G , Tsoy M A , Kravtsova A Y 
Published: April 2021

AbstractThe arising of the cavitation cavity behind the circular cylinder with aspect ratio 0.06 has been investigated using high-speed visualization. High-speed imaging at a sampling rate up to 200 kHz and even higher for the local areas allowed the spatial structure and dynamics of gas-vapor cavities thoroughly to be studied. The time dependence of the volume of the cavitation cavity on time was obtained for all investigated regimes. The vapor volume fraction, as expected, was found to increase with a decrease in cavitation number at higher flowrates. The feature of the separated cavitation cavity behind the cylinder is the complex structure consisting of the set of the flatted bubbles with a thin liquid interface between them. The collapse of the cavitation cavity proved to be always initiated only near one of the channel walls.
Void fraction of nitrogen-water flow in flat microchannels
Authors: Dementyev Yu A , Ronshin F V , Chinnov E A 
Published: April 2021

Abstract
In this study, we investigated a behavior of time-averaged void fraction in five flat microchannels with cross sectional area of 0.05x10, 0.09x10, 0.15x10, 0.05x20 and 0.15x20 mm2. The experiments have been conducted at fixed superficial velocity of liquid phase. The dependence between time-averaged void fraction and superficial gas velocity has been studied. It was shown, that this dependence may be approximate by power law with R2=0.968. The dependence between time-averaged void fraction and homogeneous void fraction has been investigated. It was shown that the height of channel has not been affected by void fraction behavior, however the width of channel has influence: with an increasing of the channel width the dependence line shifts towards lager homogeneous fractions. However to take into account the influence of the channel width on surface area occupied by gas and to generalize data further investigations are required.
Plasma-chemical synthesis of germanium nanotubes
Authors: Timerkaev B A , Kaleeva A A , Feltsinger V S , Zalialieva A A , Suleimanov R M , Ibragimov I S , Sorokina A R , Akhmetvaleeva A R 
Published: April 2021

Abstract
The paper describes the synthesis of germanium nanotubes in an argon microarc. The article presents the results of two experiments. The evaporation of germanium atoms was carried out from the surface of single-crystal germanium, which served as the anode of the microarc discharge. The synthesis of nanotubes was observed on the surface of a molybdenum cathode in the first experiment and on the surface of a graphite rod in the second experiment. The diameters of the obtained germanium nanotubes reach 800-900nm.
Simulation of electrical characteristics of positive glow discharge column in plane channel with longitudinal gas flow and additional gas injection through the side wall
Authors: Galeev I G , Asadullin T Y , Tsybikov R O 
Published: April 2021

Abstract
A model of positive glow discharge column in longitudinal flowing glow discharge with additional gas injection through the side wall is proposed. The main flow is pumped through the mesh electrodes located at the beginning and end of the plane discharge chamber. Analytical expressions are obtained for the distribution of the most important electrical characteristics in the discharge region: the electric field strength and the degree of gas ionization.
On the effect of large-scale perturbations of surface of a liquid electrolyte cathode on the properties of gas
Authors: Tazmeev A K , Tazmeeva R N , Tazmeev B K 
Published: April 2021

AbstractA gas discharge between a liquid electrolyte cathode and a copper anode was experimentally investigated in the current range of 1-15 A in the presence of disturbances on electrolyte surface. Two options were considered. In the first variant, disturbances were created by supplying gas to the inside of surface layer of electrolyte. And in the second version, a two-level cathode zone was organised on the electrolyte surface.
Influence of magnetron sputtering modes of aluminum and aluminum nitride films on their surface, structure and composition
Authors: Baranova L V , Strunin V I , Chirikov N. A. 
Published: April 2021

Abstract
To ensure the optimal combination of the properties of the thin-film layers of piezoelectric structures and achieve the required characteristics of resonators and devices for selecting and generating of the signals based on them, the influence of technological modes of aluminum nitride films formation on the surface morphology, structure and elemental composition of films used in the construction of microelectronic bulk acoustic waves (BAW) resonator with Bragg reflector, the optimal modes are determined that satisfy the requirements for film layers for a piezoelectric transducer and Bragg reflector.
Effects of Sloped Trench Casing Treatment Combined with Air Injection on Stall Triggering Factor of a 1.5 Stage Axial Flow Compressor
Authors: Kai-kai Zou , Yong-bao Liu , You-hong Yu , Xing He 
Published: April 2021

Abstract
A new mode, sloped trench casing treatment combined with air injection, was designed and introduced in a 1.5 stage axial compressor. To reveal the effects of this mode on the aerodynamic stability, a three-dimensional numerical simulation was carried out. Results show that sloped trench casing treatment combined with air injection could improve the stable operating range, total pressure ratio, and adiabatic efficiency of the compressor simultaneously. The optimal configuration obtains the stable range extension of 26.47% by using only 0.69% of the whole annulus mass flow rate. Based on a comparison of the stall routes, it is found that the smooth casing compressor occurring stall is caused by a blockage cell formed mainly by the low-velocity tip leakage flow. However, the stall of the sloped trench casing compressor with air injection is caused by a considerable blockage cell formed jointly by the low-velocity tip leakage flow and separated flow on the suction surface of the middle-upper span of the rotor blade. The latter’s contribution cannot be neglected.
The Effect of Crosslinking Mixture Addition on the mechanical properties of PU Polymeric Matrix
Authors: Boshra Islam K. , Lin Guo , Elhedery Tarek 
Published: April 2021

Abstract
Polyurethanes are prepared by extending a prepolymer chains made from a macro diol and a diisocyanate and its mechanical properties could be improved by using special additives to enhance the crosslinking process. In this study, 15 hydroxyl terminated polybutadiene (HTPB) based poly urethanes were prepared using 1, 6- hexamethylene diisocyanate (HMDI) and crosslinking mixture (CM) consists of trimethylol propane (TMP) as a triol crosslinker and butane diol (BD) as a chain extender. Five different crosslinking mixtures were used through the combination between TMP: BD = 1:0, 0:1, 1:1, 2:1 and 1:2. The research investigated the impact occurred on the mechanical behaviour of PU formulations prepared by adding certain cross-linking additives with various content from 0 % to 5 % and the curing ratio NCO/OH maintained constant at 0.7. The strength-strain relationships of all the finished samples were determined by using a LLOYD testing machine. The mechanical properties have been plotted vs. crosslinking mixture content and TMP: BD percentage which could be utilized to choose an appropriate network forming agent formulation for a particular grain technology and implementation. It was concluded that both TMP and BD have a major influence on the mechanical behaviour which allow obtaining a wide range of strength and elongation capabilities. The tensile strength increased by the excess of triol addition while the strain had a lowering effect which was compensated by the existence of diol extender. Tailoring the mechanical characteristics was easy to make by using a suitable proportions of TMP and BD to obtain outstanding mechanical properties for fixed NCO/OH, especially elastic capabilities, compared to polyurethanes formulated without any crosslinking additives.
Comparison of RBFs Interpolation for Load Transfer on Wing Structure
Authors: Cheng Pan , Zhao Yang , Sun Yuchen 
Published: April 2021

Abstract
Load transfer is of importance in simulation of aeroelasticity by coupling with CFD and FEM. Different RBFs (Radial Basis Function) with variant parameters are tested in load transfer and their results are compared in this paper. Result comparison shows that different RBFs with variant parameter will lead to different results. More approximate load on structure can be gained by MQB and TPS functions. The compact support RBFs should be used with wisely chosen support radius to gain approximate results.
Research on the Key Technology of Propulsion Drag System Division and Performance Analysis of Turboprop-powered Aircraft
Authors: Yiting Wu , Zhengzhong Yuan , Zhihang Cheng , Yang Tao 
Published: April 2021

Abstract
The remarkable characteristic of turboprop-powered aircraft is that its power system has great influence on the aerodynamic characteristics of the aircraft. Due to the action of turboprop slipstream, the airflow velocity after the propeller is obviously increased compared with the velocity of free flow. The turbulence caused by turboprop slipstream affects the aerodynamics of the aircraft, which in turn affects the performance of turboprop blades. In this paper, the layout characteristic and development trend of turboprop powered aircraft are briefly analysed. According to the characteristics of turboprop aircraft, a thrust/drag system division principle and interference characteristics treatment method for turboprop powered aircraft are introduced. Finally the influence of slipstream on a typical turboprop powered aircraft is analysed, It is very necessary to study the influence of propeller slipstream on aircraft aerodynamic performance in the early stage of developmental the effect of propeller slipstream on the aerodynamic characteristics of the whole aircraft is the strongest in take-off state, the influence of climbing state is weakened the influence of cruise state is the lease and the effect of slipstream effect increases with the increase of thrust.
The Problem of Elements Returning of Launch Vehicles and the Ways of Its Solution
Authors: Kretov A. , Mekhonoshin Yu. , Usmonov T. 
Published: April 2021

Abstract
The work, dedicated to the blessed memory of Vladimir Chizhukhin, deals with the problem of rescuing the blocks of carrier rockets for their subsequent use. The priority method is the use of aerospace parachute systems (ASPS), which are the lightest of all possible rescue systems. The possibility of using parachutes at space altitudes has been proven by the longterm practice of using them in M-100 meteorological rockets. Based on specific examples, numerical studies have been carried out on the possibility of using such a system, showing its great capabilities in combination with helicopter pick-up at the final stage of landing or with a rocket-dynamic soft-landing system.