bluuebunny/crossref_metadata_2025_split huggingface dataset:
HVPE growth of bulk GaN with high conductivity for vertical devices
Authors: Xia Songyuan , Zhang Yumin , Wang Jianfeng , Chen Jihu , Xu Ke 
Published: November 2020

Abstract
The electrical properties of gallium nitride (GaN) substrate are crucial to the performance of vertical power devices. Bulk GaN substrates with carrier concentrations in the range from 6.7 × 1017 to 1.7 × 1019 cm−3 are grown by hydride vapor phase epitaxy. All samples show no obvious tensile stress regardless of the carrier concentration. Moreover, the mobility of Si-doped high-quality bulk GaN is superior to the GaN template with higher dislocation density at the same carrier concentration. The influence of carrier concentration on the performance of ohmic contact on N-face of Si-doped GaN is also carefully studied by circular transfer length measurement and rapid thermal annealing methods. The specific contact resistivity decreases monotonically with increase of carrier concentration, while it increases with the annealing temperature. The N-face contact becomes non-ohmic when the annealing temperature exceeds the limit value, which increases with the carrier concentration. The sample with carrier concentration of 1.7 × 1019 cm−3 still showed ohmic behavior after annealing at 450 °C. These results are not only useful to improve the electrical properties of N-type bulk GaN substrate, but also provide a potential solution for improving the efficiency of vertical devices in the future.
High-speed interrogation of multiplexed fiber Bragg grating sensors for monitoring dynamic strain responses during a flexible plate impact on a water surface
Authors: Wong Kit Pan , Kim Hyun-Tae , Wang An , Kiger Kenneth , Duncan James H , Yu Miao 
Published: November 2020

Abstract
The investigation of fluid-structure interaction during the impact of a flexible plate on a water surface has received much attention. Measurement of highly transient, distributed strain of the plate during the slamming event is of great interest. Multiplexed fiber Bragg grating (FBG) strain sensors provide a promising solution for such measurement since these sensors are inherently waterproof and are immune to electromagnetic interference. However, in order to monitor the highly transient, distributed strain responses (up to 20 kHz), high-speed simultaneous interrogation of multiplexed FBG sensors is required, which is challenging by using commercial optical interrogators. We present a tunable-wavelength-filter-based optical interrogation system for high-speed simultaneous interrogation of multiplexed FBG strain sensors and demonstrate its application for structural monitoring of a flexible plate during the slamming event. The interrogation system employs a piezoelectric-transducer-controlled Fabry–Perot tunable filter. By operating the tunable filter at its resonant frequency and demodulating the sensor signal based on a peak tracing method, we demonstrated an interrogation speed of 100 kHz, an interrogation range of 98 nm, and an interrogation resolution of 5 pm. For proof-of-performance, the interrogation system was used to monitor the vibrational responses of a cantilever plate under impact loading and the measurement of vibration modes up to 6.785 kHz was demonstrated. Finally, the slamming experiments were carried out with six multiplexed FBG strain sensors mounted on a flexible plate. The dynamic strain measurement of the plate during the slamming event was successfully demonstrated by using the high-speed FBG interrogation system.
Universal function of the diffractive process in color dipole picture
Authors: Jalilian Z. , Boroun G. R. 
Published: November 2020

Abstract
In this study, we obtain the universal function corresponding to the diffractive process and show that the cross section exhibits geometrical scaling. It is observed that diffractive theory according to the color dipole approach at small-x is a convenient framework that reveals the color transparency and saturation phenomena. We also calculate the contribution of heavy quark production in the diffractive cross section at high energy that is determined by the small size dipole configuration. The ratio of the diffractive cross section to the total cross section in electron-proton collision is the other important quantity that is computed in this work.
CXRS measurements of energetic helium ions in ASDEX Upgrade plasmas heated with a 3-ion ICRF scenario
Authors: Kappatou A. , Weiland M. , Bilato R. , Kazakov Ye.O. , Dux R. , Bobkov V. , Pütterich T. , McDermott R.M. 
Published: November 2020

Abstract
Fast ion physics is an active field of research in the fusion community, but most studies focus on deuterium fast ions. The generation and investigation of energetic helium in present devices, however, provide significantly more insight on how the fast alpha particles produced from fusion reactions, will behave in future reactor plasmas. Fast helium ion populations can be measured with charge exchange recombination spectroscopy (CXRS) in the wings of the helium spectral line (He II
n = 4–3, 468.6 nm) providing information on their distribution function. CXRS measurements of energetic 3He ions, a first for ASDEX Upgrade, are presented. The 3He ions are accelerated to high energies by a three-ion cyclotron resonance frequency (ICRF) heating scenario in a mixed hydrogen–deuterium plasma. The spectral signature of the energetic helium ions in the charge exchange spectra is presented and compared with the theoretical predictions obtained with the TORIC-SSFPQL code. The magnitude of the predicted charge exchange spectral radiance, obtained via forward-modelling of the spectrum utilising TORIC-SSFPQL distribution functions, and the expected energies of the ions agree well with the measurement, confirming that the spectral feature is due to ICRF-accelerated 3He ions. Comparisons between the experimental measurement and the modelling reveal discrepancies that illuminate details of the velocity distribution function of these ions.
Low-complexity eigenstates of a
ν
= 1/3 fractional quantum Hall system
Authors: Nachtergaele Bruno , Warzel Simone , Young Amanda 
Published: November 2020

Abstract
We identify the ground-state of a truncated version of Haldane’s pseudo-potential Hamiltonian in the thin cylinder geometry as being composed of exponentially many fragmented matrix product states. These states are constructed by lattice tilings and their properties are discussed. We also report on a proof of a spectral gap, which implies the incompressibility of the underlying fractional quantum Hall liquid at maximal filling ν = 1/3. Low-energy excitations and an extensive number of many-body scars at positive energy density, but nevertheless low complexity, are also identified using the concept of tilings.
Calculation of the thermodynamic characteristics of an upward swirling gas flow under conditions of side wind
Authors: Obukhov A G 
Published: November 2020

Abstract
The paper presents the results of numerical modeling of lateral wind effects on three-dimensional unsteady air flows in an upward swirling stream of an artificially created tornado after entering a stationary mode. Under the corresponding initial and boundary conditions, the solutions of the complete system of Navier-Stokes equations in the computational domain in the form of a rectangular parallelepiped are numerically obtained using the explicit difference scheme. At fixed points in time, the gas-dynamic characteristics of air flows are calculated under the action of gravity and Coriolis, as well as taking into account the constant horizontal directional wind speed. Numerical calculations showed that the resulting density, temperature, and pressure gradients lead to significant and asymmetric changes in air flows at different points in time and at different points in the computational domain. The total displacement of the vortex in the direction of the wind, the deformation and increase in the diameter of the vortex, which begin in the bottom part and pass into its vertical part, are established. In the considered range of time changes, the stability of the air vortex under study against wind action and the stable operation of the computational scheme used are noted.
Thermal impact of buried reservoirs with industrial waste of the fuel and energy complex on frozen soils
Authors: Zemenkova M Yu , Mikhailov P Yu , Shabarov A B , Shastunova U Yu 
Published: November 2020

Abstract
The oil and gas industry has been intensively developing in the far north of the Russian Federation. Underground tanks are repositories of waste from processed petroleum products, liquefied gas, condensate, process water, and other waste from the fuel and energy complex. High-quality underground disposal of industrial waste can eliminate leakage of chemicals into the soil and reduce the thermal effect on frozen soil. The article presents an algorithm for calculating the thermal effect of industrial “hot” waste of the fuel and energy industry on frozen soil. Heat fluxes from a 20,000 m3 tank are estimated, an area of soil thawing is calculated. An engineering solution was developed to reduce / eliminate this effect.
Use of collapsible pipelines for joint work with main oil product pipelines
Authors: Melnikov D I , Zemenkova M Yu , Podorozhnikov S Yu 
Published: November 2020

Abstract
The paper describes development stages for dismountable pipelines to work together with the major oil pipeline. Dismountable pipelines are used for transporting refined oil volumes over great distances in any climatic and geographical conditions. A dismountable construction provides technological pipeline schemes for rapid transportation and distribution of refined oil products to storage tanks. Subsequently, these products from containers can be utilized for various purposes.
Development of an algorithm for determining the optimal start time of oil wells to reduce the peak load
Authors: Klyuev R V , Bosikov I I , Tavasiev V Kh , Gavrina O A 
Published: November 2020

Abstract
The subject of this work is the development of an algorithm for determining the start time of wells in the automatic re-activation mode to save power during peak hours. This measure is relevant for the consumer and for the energy-supplying organizations, because the redistribution of load on peak hours or night zones will provide the most economically balanced operation of the enterprise, and will allow the most efficient use of sources of electrical energy supply organization. The algorithm development will provide operational control and management of the operating mode of the considered equipment in automatic mode. Besides, this will reduce the influence of the human factor on the operation of these consumers and minimize deviations in the hourly planning of electricity consumption, as well as reduce the cost of paying for consumed power. The short-term prospect of implementing this development will ensure optimal power consumption of the periodic well stock during peak load hours, and, consequently, will provide savings in the material resources of the enterprise.
Classification and features of projects in the oil and gas industry
Authors: Bovkun A S , Arkhipkin O V , Koroduk I S , Krupchenko A A 
Published: November 2020

Abstract
Project management has been widely used in various fields and sectors of the economy over the past years. Projects implemented in the oil and gas industry have significant differences between them. To choose the optimal approach to managing an oil and gas project, firstly, the distinctive features of the project type should be identified in advance. The use of project classification makes it possible to optimize methods and tools for managing specific projects and increase the efficiency of their implementation. The article analyzes the classification of projects. The main classification features and types of projects most commonly used in scientific literature and practice are identified. In the course of the research, it was found that the presented approaches to the classification of project management do not sufficiently take into account the branch of economy in which they are implemented. Therefore, the classification of projects in a particular sector of economy may have its own classification features applicable only to the specific industry. The oil and gas industry is considered as a separate branch of economy. The article considers the most well-known oil and gas production projects implemented in recent years. The analysis of the projects has shown there is a number of features that are different from other projects. Therefore, for detailed classification of oil and gas projects, the author’s classification features of projects significantly affecting the financial costs and timing of implementation of oil and gas projects are presented.
Preliminary zoning of negative impact of the projected oil waste polygon at the Samotlor field
Authors: Aitov I S , Khudaiberdiev A T 
Published: November 2020

Abstract
This paper provides a comprehensive analysis of the building expediency of a polygon for processing oil wastes in KhMAD-Yugra. Preliminary research has shown the environmentally dangerous impact of its project location relative to Nizhnevartovsk city, village Izluchinsk and village Bolshetarkhovo, as well as other important objects. The method of location estimation based on the main rules of life safety is proposed. Its application will reduce the environmentally dangerous impact and make it possible to choose the most optimal location of the polygon. An environmental pollution assessment scale has been developed, presented in tabular form for convenience. The area of zones of different dangerous influence degrees is calculated. The article describes the increase in the probability of earthquakes, wildland fires and floods in the area of the Samotlor field polygon due to global warming. The article also considers the prospect of using GIS programs in modeling environmental phenomena that affect oil and gas production facilities.
An analysis of the effectiveness of hydraulic fracturing at YS1 of the Northern field
Authors: Karpikov A V , Aliev R I , Babyr N V 
Published: November 2020

Abstract
There are many methods of enhanced oil recovery and stimulation of oil inflow, and in order to find their most effective application, it is necessary to study the object of works, candidate wells, as well as their impacts on these wells. One of the methods of production intensification, which makes it possible to improve profitability of oil extraction, is hydraulic fracturing.
Hydraulically perfect modes of injection of grouting mixtures when isolating absorbing formations
Authors: Chizhov A P , Andreev V E , Chibisov A V , Mukhametshin V V , Kuleshova L S 
Published: November 2020

Abstract
The article deals with a mechanism of isolation of absorbing intervals during the construction of oil and gas wells. Research is based on systemic approaches to complex scientific and technical problems. The results of laboratory and technological experiments aimed at improving the hydromechanical processes of cementation of absorbing rocks are presented. Various technological schemes for injecting hardening solutions into intervals of absorbing formations, the mechanism of interaction between solutions and permeable rocks, hydraulically perfect modes of injection of backfill mixtures and quality and efficiency of insulation works are analyzed.
Probabilistic statistical model for predicting the effectiveness of hydraulic fracturing
Authors: Gabdrakhmanova K F , Izmaylova G R , Samigullina L Z 
Published: November 2020

Abstract
The article studies the effectiveness of single-stage and multi-stage hydraulic fracturing technologies using the mathematical statistics method. The studies are based on the geological and physical characteristics of the Shirotny Priob fields which makes it possible to substantiate the methods for choosing the hydraulic fracturing technology. Based on the probabilistic and statistical analysis of field efficiency data, quantitative criteria for the selection of fracture parameters by length, height and amount of injected propane have been established. They can be used to predict the use of multi-stage and single-stage hydraulic fracturing methods. The productive horizon AS12-3 has a complex geological and physical structure and low filtration and storage properties, which complicates its development and contributes to the active formation of hard-to-recover reserves. The one-stage hydraulic fracturing technology is efficient only for 3-4 years. The multistage hydraulic fracturing technology showed is more efficient in comparison with the single-stage one.
Improving equipment and technology for selective acid treatment of wells
Authors: Khabibullin M Ya 
Published: November 2020

Abstract
This method is based on the following effect. A channel in the selected formation layer or section is formed by sandblasting. The acid solution is pumped into the channel through the nozzle of the perforator. The stream of acidic solution entering the channel prevents this solution from leaving the channel. In order to increase the acid depletion time, i.e. to slow down the reaction rate, it is necessary to add special reagents to the solution. Syntanol DS-10 TU 2483-016-71150986-2012 (a non-ionic surfactant used as an effective surfactant) is a very effective reaction rate reducer. Adding it in an amount of 0.5% (by weight of the volume of the solution) one can reduce the reaction rate by 2.7 times. It is much more difficult to increase the rate of acid solution injection into highly drained formations of low-production wells (up to 5–10 tons of fluid per day) with a low reservoir pressure due to the insufficient capacity of acid aggregates.
Developing the efficiency of low-productivity oil deposits via internal flooding
Authors: Soloviev N N , Mukhametshin V Sh , Safiullina A R 
Published: November 2020

Abstract
The article studies geological and technological parameters’ impact on degree and nature of production wells. The wells influence the water injection into wells in the carbonate reservoirs of the Tournaisian stage of the Birsk saddle. The study presents an algorithm with substantiating technological solutions to increase the efficiency of developing low-productive deposits via internal flooding. It also considers the development of facilities for hard-to-recover reserves with high production costs and low profitability. This is made in order to use the resource base of the Volga-Ural oil and gas provinces more efficiently.
Improved handling of 4x4 vehicles with differential transmission in curved driving on support surfaces with low coupling properties
Authors: Zhileykin M 
Published: November 2020

Abstract
Studying the trends in the development of modern automotive industry, you can see that manufacturers are constantly increasing the level of control over the parameters of the movement of wheeled vehicles, achieving the maximum level of stability and controllability of cars. The purpose of this work is to improve the handling of vehicles with a 4x4 wheel formula with a differential transmission in curved motion on support surfaces with low coupling properties. An algorithm is proposed to improve the handling of vehicles with a 4x4 wheel formula with a differential transmission in curved motion on support surfaces with low coupling properties due to braking of individual wheels. The efficiency and efficiency of the proposed algorithm is proved by the methods of simulation of the movement of two-axle cars with a 4x4 wheel formula with a differential transmission.
Optimization of the flow part of the pump for abrasive-containing liquids by hydrodynamic modeling methods
Authors: Martynyuk O , Petrov A 
Published: November 2020

Abstract
Abstact. In this article the severe operating conditions of pumps for abrasive media, as well as the complexity of obtaining an analytical solution to the wear problem are described. Optimization criteria for such pumps are selected. A mathematical model for calculating a ground pump is presented. The STAR CCM+ software package modeled 15 models with different geometries and identified the main geometry parameters that affect the rate of erosion. A weight function was created that characterizes the success of model optimization based on the selected criteria. According to the accepted parameters, 20 models were modeled and the best geometric dimensions of the flow part were selected. The results are analyzed and conclusions are drawn.
Quasi-static bending of thin-walled beams with different fillers under extreme load for solving the problems of crashworthiness
Authors: Goncharov R , Zuzov V 
Published: November 2020

Abstract
In this paper, there are issues related to the choice of elemental modelling of thin-walled beams with various types of fillers for quasi-static bending loading, which causes washing of beams and filler, as applied to the optimal design. The objects of research are thin-walled beams made of aluminium AMG6 contains fillers made of aluminium foam, epoxy resin and composite (consisting of Poraver balls and epoxy resin). One of the best fillers for solving the problems of crashworthiness is requiring expensive technological equipment for filling. Epoxy resin is a fragile material, but inexpensive, affordable and technologically “convenient”. In addition to the influence of the filler on the mechanical properties of beams, the effects of the constrained behaviour of the material of the filler under the bending loading of beams are investigated with Zwick Z100 (for hollow thin-walled beams made of aluminium and the same beams with fillers).The paper presents the results of numerical calculations and the results of the experiment (the error of calculations does not exceed 8%).The most rational is the ratio between the indicators of energy intensity - the mass is aluminium-foam (with an increase in the mass of the sample by 2,1 times the mechanical properties reach 10 of times). The remaining fillers give significantly worse results for the same parameters. To assess the effectiveness of the use and creation materials for the refinement of the cabins and car bodies according to the crashworthiness.
Overview of methods for optimizing the flow of the centrifugal pump
Authors: Gradilenko N , Lomakin V 
Published: November 2020

Abstract
Abstact. This article is devoted to a review of the flow part of the centrifugal pumps(CFP), as well as methods for its optimization. The components of the flow part (inlet, impeller and outlet) were considered, and methods for their optimization were given. The analysis of the literature was carried out. Conclusions are drawn on the development and improvement of vane pumps.
Thermal processes in the electromechanical mandrel of holes in steel billets
Authors: Morozov A , Fedotov G , Ivanova Y , Khabieva L , Knyurov A 
Published: November 2020

Abstract
The article presents findings on the distribution of temperature fields during Electromechanical mandreling (EMM) of holes in the surface of the workpiece and the tool. The design temperatures significantly exceed the phase transformation temperatures, but the melting of structural components in the surface layer of the workpiece does not occur due to high cooling rates. It is not possible to fix the maximum process temperatures experimentally due to their short duration of action.