bluuebunny/crossref_metadata_2025_split huggingface dataset:
The JOREK non-linear extended MHD code and applications to large-scale instabilities and their control in magnetically confined fusion plasmas
Authors: Hoelzl M. , Huijsmans G.T.A. , Pamela S.J.P. , Bécoulet M. , Nardon E. , Artola F.J. , Nkonga B. , Atanasiu C.V. , Bandaru V. , Bhole A. , Bonfiglio D. , Cathey A. , Czarny O. , Dvornova A. , Fehér T. , Fil A. , Franck E. , Futatani S. , Gruca M. , Guillard H. , Haverkort J.W. , Holod I. , Hu D. , Kim S.K. , Korving S.Q. , Kos L. , Krebs I. , Kripner L. , Latu G. , Liu F. , Merkel P. , Meshcheriakov D. , Mitterauer V. , Mochalskyy S. , Morales J.A. , Nies R. , Nikulsin N. , Orain F. , Pratt J. , Ramasamy R. , Ramet P. , Reux C. , Särkimäki K. , Schwarz N. , Singh Verma P. , Smith S.F. , Sommariva C. , Strumberger E. , van Vugt D.C. , Verbeek M. , Westerhof E. , Wieschollek F. , Zielinski J. 
Published: April 2021

Abstract
JOREK is a massively parallel fully implicit non-linear extended magneto-hydrodynamic (MHD) code for realistic tokamak X-point plasmas. It has become a widely used versatile simulation code for studying large-scale plasma instabilities and their control and is continuously developed in an international community with strong involvements in the European fusion research programme and ITER organization. This article gives a comprehensive overview of the physics models implemented, numerical methods applied for solving the equations and physics studies performed with the code. A dedicated section highlights some of the verification work done for the code. A hierarchy of different physics models is available including a free boundary and resistive wall extension and hybrid kinetic-fluid models. The code allows for flux-surface aligned iso-parametric finite element grids in single and double X-point plasmas which can be extended to the true physical walls and uses a robust fully implicit time stepping. Particular focus is laid on plasma edge and scrape-off layer (SOL) physics as well as disruption related phenomena. Among the key results obtained with JOREK regarding plasma edge and SOL, are deep insights into the dynamics of edge localized modes (ELMs), ELM cycles, and ELM control by resonant magnetic perturbations, pellet injection, as well as by vertical magnetic kicks. Also ELM free regimes, detachment physics, the generation and transport of impurities during an ELM, and electrostatic turbulence in the pedestal region are investigated. Regarding disruptions, the focus is on the dynamics of the thermal quench (TQ) and current quench triggered by massive gas injection and shattered pellet injection, runaway electron (RE) dynamics as well as the RE interaction with MHD modes, and vertical displacement events. Also the seeding and suppression of tearing modes (TMs), the dynamics of naturally occurring TQs triggered by locked modes, and radiative collapses are being studied.
Construction and Applications of Stairboxplot for Exploratory Data Analysis
Authors: Babura Babangida Ibrahim , Adam Mohd Bakri , Sani Muhammad , Waziri Usman , Eguda Felix Yakubu 
Published: April 2021

AbstractThe classical construction of boxplot requires estimates of five robust statistics of interest namely, the first quartile, the median, the third quartile, the lower fence and the upper fence. The fence estimate is usually dependent on the three quartiles and is utilized to visually identify outliers in a batch of univariate dataset. Some scholars are critical of the limitation of boxplox to display individual data points, density of observations and distributional shape in multiple batch comparison among to mention. In this paper display enhancement to address the limitations of classical boxplot is proposed according to a new construction method called stairboxplot. The construction begins with display of four stairs of consecutive boxes according to quadbins to replace box and whiskers in the classical boxplot construction and an inscription of individual observations using scale adjusted outlyingness estimate of each data point. The advantage of stairboxplot as a data display toolkit was explored using simulation and real life dataset.
Experimental study of gas jet outflow from a supersonic nozzle with a screen into vacuum
Authors: Vyazov Y N , Prikhodko V G , Yarygin I V 
Published: April 2021

Abstract
The flow structure formed behind supersonic nozzle with a screen under joint outflow of gas and near-wall liquid film into vacuum is studied experimentally. Pressure in cavity between the nozzle and the screen is measured. Transversal pressure profiles in a jet behind the nozzle for different values of background gas pressure in the vacuum chamber are obtained. The significant effect of the screen on droplet phase flow structure behind the nozzle is shown.
Deposition of fluoropolymer coating on a metal mesh for manufacturing of oil-water emulsion separating membranes
Authors: Melnik A V , Petrova A V , Bogoslovtseva A L , Safonov A I 
Published: April 2021

Abstract
The membranes were synthesized by deposition of fluoropolymer coatings on metal meshes using the Hot Wire Chemical Vapor Deposition (HW CVD). The obtained membranes were used for the separation of an oil-water emulsion in a simple filtration facility. The main process parameters influencing the separation efficiency were determined and the optimal separation mode was selected. It was shown that the highest efficiency on the obtained membranes is achieved by separating emulsions containing water less 10%.
Gradient heatmetry in the study of boiling on spherical surface
Authors: Sapoznikov S Z , Mityakov V Yu , Pavlov A V , Bobylev P G , Vinogradov M D 
Published: April 2021

Abstract
The combination of methods of gradient heatmeatry and high-speed visualization made it possible to compare the distribution of the local heat flux and the hydrodynamics of the process during boiling of subcooled water on the surface of the sphere. The results are compared with the works of other authors and conclusions are drawn about the effect of subcooling of water on the intensity of heat transfer.
Experimental study of the plug flow of immiscible liquids with non-Newtonian properties in a T-shaped microchannel
Authors: Yagodnitsyna A A , Kovalev A V , Bilsky A V 
Published: April 2021

Abstract
The present paper aims to study the plug flow of immiscible liquids when the dispersed phase exhibits non-Newtonian properties. Plug formation regimes were studied both for the non-Newtonian dispersed phase case and three sets of Newtonian liquids with different viscosities. Plug length was measured and compared for various flow rates of the continuous and dispersed phases. It was shown that plug length could be dramatically increased by using non-Newtonian liquid as the dispersed phase.
An experimental investigation of the heat transfer dynamics during drop impact onto a liquid layer
Authors: Gigola T G , Cheverda V V , Karchevsky A L , Kabov O A 
Published: April 2021

Abstract
In the present work an experimental investigation of a drop impact onto a liquid layer of certain thickness placed on a heated thin foil is presented. The heat transfer and dynamics of drop impact on liquid surface has been studied and visualised with using infrared thermography. The experimental data obtained by means of an infrared scanner, that is, the measured temperature distributions on the opposite side of the foil will be used for the next stage of the research. The primary task of the research is to determine the heat flux from the foil by solving Cauchy problem for the non-stationary heat transfer equation that describes the heat conductivity inside the foil.
NORBY CubeSat nanosatellite: design challenges and the first flight data
Authors: Prokopyev V Yu , Bakanov S S , Bodrov V K , Chernodarov E N , Doroshkin A A , Gorev V N , Kolesnikova A Yu , Kozlov A S , Kus O. N. , Melkov A V , Mitrokhin A A , Morsin A A , Nazarenko A E , Neskorodev I V , Pelemeshko A V , Prokopyev Yu M , Romanov D A , Shilov A M , Shirokih M V , Sidorchuk A A , Styuf A S , Zadorozhny A M 
Published: April 2021

Abstract
The paper presents the NORBY 6U CubeSat nanosatellite’ launched on 28 September 2020 into a low-Earth orbit. The design of NORBY is briefly described’ the main characteristics of its subsystems are given’ and the results of the first flight tests are presented. The main features of the NORBY design are full hardware duplication of all subsystems and information interfaces’ as well as the use of LoRa modulation in radio communications between the satellite and a ground station. The first results of the NORBY flight tests confirm the effectiveness of the key technical solutions applied in the NORBY design. For the first time’ the operability of the LoRa modulation in satellite radio communications has been experimentally confirmed. The LoRa satellite-to-ground radio channel functioned sustainably at all tested parameters.
Micro-arc method for the synthesis of silicon nanostructures
Authors: Kaleeva A. A. , Timerkaev B. A. , Shamsutdinov R. S. , Saifutdinova A. A. , Shakirov B. R. 
Published: April 2021

Abstract
This paper presents the results of plasma synthesis of silicon nanostructures in an air-argon medium. The synthesis of silicon nanostructures was carried out in a vacuum chamber at a gas mixture pressure of 500 Torr, with partial pressures of argon and air in the ratio of 4:1. Molybdenum and silicon embedded in a copper tube were used as electrodes. Current and voltage were maintained in the range of 8-25 A and 30-50 V, corresponding. As a result of experiments, silicon nanostructures were deposited on the surface of the electrodes. Nanostructures were studied by optical and electron microscopes. Forms of silicon nanostructures were mainly in the form of nanotubes. Their diameters range from 200 nm to 500 nm, and their length reaches 1 mm. On the surface of these nanotubes, nanovilli with a diameter of about 5 nm and a length of 100 nm are observed.
Calculation of conditions for maintaining an ICRF-plasma using a self-consistent model
Authors: Zheltukhin V S , Terentev T N , Shemakhin A Y , Samsonova E S 
Published: April 2021

Abstract
The article proposes a new approach to calculating the strength of the magnetic field on the inner wall of the discharge chamber, which is necessary to maintain a steady state of a low-pressure ICRF discharge. The model is treate as a nonlinear eigenproblem. The influence of the third type boundary conditions for electron density as well as and the nonlinear boundary conditions for electrical strength is considered. This approach makes it possible solving two problems of designing ICRF plasma torches: for a given electron density in the discharge find the magnetic field strength that ensures the maintenance of the discharge, or, conversely, at a given magnetic field strength, determine the value of the electron density that can be created in the discharge. In addition, the radial distributions of the electric and magnetic fields and the electron concentration can be determined.
Spin excitation kinetics in paramagnet by microwave field pulse
Authors: Asadullina N Y , Asadullin T Y 
Published: April 2021

Abstract
This work is devoted to the study of the kinetics of electron spins excitation in solid-state dilute paramagnets in the process of transient nutations. Transitional nutations are the response of a system, initially in thermal equilibrium, to a suddenly applied very intense resonance field during its transition to a new stationary state. The decay rate of the signal is determined by the interaction of active spins with each other Γac (Δ, t) ∼ nac (Δ, t) and active spins with passive Γpas (Δ, t) ∼ npas (Δ, t). Therefore, the challenge is to find these concentrations. They are obtained by solving kinetic (rate) equations.
Analysis of Intermediate Casing Wear in Ultra-deep Wells in China’s Tarim Oil Field
Authors: Ma Chao , Gao Baokui , Wang Jieli , Hu Tianxiang , Chen Xingwang 
Published: April 2021

Abstract
Intermediate casing wear with a spiral scar is often found in ultra-deep wells in Tarim Oil Field. In this work, the mechanism of such wear, and the measures to reduce wear are analyzed. Comparing the geometric characteristics of the wear scars, the root cause is found that the effective inner diameter of the casing is smaller than the outer diameter of the drill pipe joint after the uncemented casing helically buckled. To analyze the main factors affecting the helical buckling of the casing, the classical pipe mechanics theory is used and Well-X in Tarim area is taken as an example. The results show that too small hanging weight is the main cause of helical buckling of the casing. Besides downhole high temperature and large hole diameter enlargement rate are also important factors. The main measures, such as increasing the hanging weight, installing centralizers, and using graded cementation, have been proposed to reduce wear.
A Landing Impact Simulation Test Method for Lunar Lander
Authors: Zhang Wenbing , Li Dong , Zhu Jianbing , Qiu Hanping , Fan Shichao , Li Xinming , Zhang Jungang 
Published: April 2021

Abstract
The lunar lander shall be suffered transient impact load during the landing process. The structure’s ability of withstand the dynamic environment is the key to success of a soft landing. Therefore, it is necessary to conduct the simulation test of landing impact on the ground to examine and verify the structure of the lunar lander on the development stage of the lunar lander. This paper introduces the test system principle, composition and application design, and presents a method to simulate the landing surface material selection, of the design of lifting and releasing separation device, and the composition of measurement system. The test technique is both suitable for the verification test of the structure and the flight phase stage, and shall be carried out in a clean environment. The test method presented in this paper has been successfully applied in the Chang’e lunar landers.
Micro-vibration Test of High Resolution Spacecraft
Authors: Minghui Liu , Hui Cao , Chuang Liu , Xiaojian Han , Dong Wang , Jiang Yang 
Published: April 2021

Abstract
The accuracy of the high resolution earth observation spacecraft has remarkably increased in recent years. The micro-vibration induced by moving machine, such as moment wheels, may cause severe disturbance to the sensitive payload onboard the spacecraft. It is crucial to perform ground micro-vibration test to verify the observation performance of the spacecraft on orbit. This paper focuses on the system level micro-vibration test method of high resolution spacecraft. The key requirements of the micro-vibration test are firstly presented, and then the test system development is introduced. Finally, the micro-vibration application technique is given to demonstrate the whole process of the micro-vibration test. It is concluded that the test method and the test system are effective for the verification of the high resolution spacecraft.
Research on the Neal&Smith Criterion Application on Aircraft Flight Control System Handling Qualities Assessment
Authors: Guo Wei 
Published: April 2021

Abstract
This paper utilized Neal&Smith criterion to quantify handling qualities of some aircraft augmented with Control and Stability Augmentation System (CSAS) over the flight envelop. Some aircraft mathematical model which augmented by longitudinal pitch Rate Command-Attitude Hold(RCAH) controller are employed. The aircraft handling qualities are described in terms of transfer functions of the pilot mathematical model, which includes a pilot’s neuromuscular delay, phase and gain compensation terms. If desirable closed loop dynamic performance can be obtained by the pilot mathematical model described by transfer function characteristics, then the satisfactory closed loop dynamic performance will also be achievable for the human pilot with decent workload. Consequently, the assessment results can be used to identify CSAS controller’s satisfactory effect domain, and furthermore, in aid of CSAS gain scheduling strategy design.
Research of a High Thermal-noise Test System Based on Progressive Wave Sound Field
Authors: Shen Zhiqiang , Fang Guiqian , Wu Yao , Li Xinming , Zhang Jungang 
Published: April 2021

Abstract
Basing on the existing situation of the thermal source, this paper designed a thermal noise load simulation test system which can make the 1200 mm×1200 mm large panel structure meet the requirement of 165 dB (GJB 150.17 A - 2009) and 1200 °C. This paper introduced the overall design and the design method of the key components. In this paper, the acoustic field uniformity of progressive wave and the acoustic field distribution at the surface of the specimen under high temperature are analyzed by means of numerical simulation. Finally, the developed system was verified by using 1200 mm×1200 mm wallboard structure which led to a stable and good effect.
Shaft friction from the DMT and direct shear interface tests
Authors: Mikina K , Konkol J , Balachowski L 
Published: April 2021

Abstract
The article presents preliminary attempt to create tri-linear transfer curves for describing pile behaviour under axial loading. Transfer curves would use the parameter measured in dilatometer test, particularly a constrained modulus MDMT. The proposed method is based on concrete rough and smooth interface tests performed in a direct shear apparatus. Based on the obtained mobilization curves, relationships were created between the parameters describing the slope of individual transfer curves and the MDMT
modulus. The obtained correlations were used to estimate the capacity of the concrete screw pile subjected to the static load test in tension.
Statistical evaluation of physical and index properties of Vistula Marshlands deltaic soft soils
Authors: Konkol J , Balachowski L 
Published: April 2021

Abstract
This paper provides statistical evaluation of physical and index parameters of the Vistula Marshlands deltaic soft soils using three datasets. Soft soils from the Vistula Marshlands are grouped into the four categories: (1) silty/sandy loams, (2) organic clays, (3) organic silts and (4) peats. Variability of basic and derivative physical properties as well as Atterberg’s limits and plasticity index is studied. It is found that index properties for all soil groups are characterized by large scatter (COV about 50%). The most reliable parameters for silty loams, organic clays and silts are soil density (COV<10%) and specific gravity (COV about 2%). Physical/index parameters of peats are characterized by large scatter, which indicates very local properties and individual formation process. Most of the data points for physical/index quantity are within ±1SD range regardless normality of data distribution. In the main body of this paper, the quantitative physical/index properties variability is evaluated and some practical design guidelines concerning variability of deltaic soil in the Vistula Marshlands are given.
Inspection of open-pit mine drainage characteristics with a horizontal borehole camera
Authors: Perdigâo C , Dyson A , Yaghoubi M , Baumgartl T 
Published: April 2021

Abstract
Horizontal bores and drains are crucial infrastructures for maintaining the stability of large open-pit mines. Induced deformations as the result of mining activities and the infiltration of water from large surface catchments during heavy rain events can cause the build-up of pore water pressures in brown coal batters. This can potentially lead to catastrophic slope failures. Horizontal boreholes and drains are commonly installed at shallow inclines and typically range in length from 150 to 400 metres. Due to complexities in surveying lengthy horizontal bores, the long-term internal properties of these structures are poorly understood. In this research, a specialised horizontal borehole camera was developed to observe a range of factors influencing borehole performance including the identification of fractured or jointed material, borehole geometry and features, and locationally dependent water outflow and drainage paths. Investigations were undertaken at an operational brown coal mine in the Latrobe Valley, located in Victoria, Australia. Features observed on the profile of horizontal bores are discussed, with an emphasis on providing in-situ material characterisation and for the purposes of maintaining stable mine batters.
Determining the subgrade reaction modulus. Mathematical approach on case study
Authors: Nagy A-Cs , Pasca D M , Fàrcas V-S , Zaharia G , Bruchental C 
Published: April 2021

Abstract
Subgrade reaction modulus (k) is the reaction pressure sustained by the soil sample under a rigid plate of standard diameter per unit settlement measured at a specified pressure or settlement. For the design of industrial slabs, the geotechnical engineer should provide two values for the subgrade modulus: the first value will be used for short-term loadings such as lift-truck wheel loads, and the second value will be used for long-term loadings such as uniform storage loads or wide area rack. Unfortunately, there are no direct laboratory procedure in order to determine the value of the subgrade reaction modulus, the only way to determine the value is by field tests or by correlation with other tests. The most common used field test is the plate bearing test. The paper is based on a case study, conducted on a site located in Romania, Maramures county. In order to verify the slab base and to determine the value of k, plate tests according to German norm DIN 18134 were performed on the site of a large logistics center in Baia Mare. Two methods were used for the interpretation of the data from the tests performed on the site. The first method is based on a program designed in Excel, and the second method is based on a program written in Qt Creator, using C++ programming language. At the end a comparison was made between the results obtained with the two use methods. The interpretation procedure presents a series of difficulties based on the form of the resulting function. These issues were addressed in the present study.