bluuebunny/crossref_metadata_2025 huggingface dataset:
Caudal autotomy and regeneration of arc in a 3D gliding arc discharge plasma
Authors: Zhang Si-Yuan , Li Xiao-Song , Li He-Ping , Liu Jing-Lin , Zhu Ai-Min
Published: May 2021

To gain a better understanding of the mechanism governing arc dynamics in 3D gliding arc discharge (GAD) plasma, the spatio-temporal evolution of GAD was investigated in a reverse vortex flow by a novel reactor with ring (powered electrode, PE) and truncated cone (ground electrode, GE) electrodes. A newly underlying mechanism governing arc evolution in 3D GAD was gained with combination of flow field simulation, synchronous electrical characteristics, intensified charge coupled device images and high-speed photos. The spatio-temporal analysis indicates that, being different from the well-known ignition–gliding–extinction mechanism occurring in traditional GAD, the PE arc root glides continuously in the 3D GAD, but the GE arc root features jumps from the end of the gliding path to the beginning of the next one. By means of the jumping, the arc auto-sheds the caudal part of the arc and a new arc tail is simultaneously generated, rather than rebuilding a new arc channel back to the shortest electrode gap. With this special behavior of caudal autotomy and regeneration, the main part of the arc remains for each jump. This new insight improves the understanding of the discharge mechanism governing arc evolution in 3D GAD and provides a reference for optimization design of gliding arc plasma in a vortex flow.
Effects of annealing in air on microstructure and hardness of hydroxyapatite ceramics
Authors: Zhu Wenliang , Imamura Hayata , Marin Elia , Adachi Tetsuya , Miyamoto Nao , Yamamoto Toshiro , Kanamura Narisato , Pezzotti Giuseppe
Published: May 2021

In this study, microstructural variation of hydroxyapatite (HAp) ceramics upon thermal treatment in air at different temperatures was investigated by x-ray diffraction patterns, Raman and x-ray photoelectron spectroscopies. The results revealed a significant dependence of the microstructure of nonstoichiometric HAp on temperature, because of the competition between hydroxylation and different kinds of dehydroxylation at different temperatures, and a gradual increase in material hardness with annealing temperature because of structural reconstruction. In summary, a suitable thermal treatment can effectively tailor microstructure and defect contents, as well as chemical composition and mechanical hardness of HAp ceramics.
Photon-in/photon-out spectroscopy at the I20-scanning beamline at diamond light source
Authors: Hayama Shusaku , Boada Roberto , Chaboy Jesús , Birt Adrian , Duller Graham , Cahill Leo , Freeman Adam , Amboage Monica , Keenan Luke , Diaz-Moreno Sofia
Published: May 2021

A scanning multi-crystal x-ray emission spectrometer to perform photon-in/photon-out spectroscopy at the I20-Scanning beamline at Diamond Light Source is described. The instrument, equipped with three analyzer crystals, is based on a 1 m Rowland circle spectrometer operating in the vertical plane. The energy resolution of the spectrometer is of the order of 1 eV, having sufficient resolving power to overcome the core-hole lifetime broadening of most of the transition metals K-edges. Examples showing the capability of the beamline for performing high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD-XAS), non-resonant x-ray emission spectroscopy (XES) and resonant x-ray emission spectroscopy are presented. The comparison of the Zn and Mn K-edge HERFD–XANES of ZnO and MnO with ab initio calculations shows that the technique provides enhanced validation of the models by making subtle spectral features more visible.
Proposed extension of double-ended gauge block interferometers for measuring spheres
Authors: Schödel René , Fischedick Markus
Published: May 2021

Double-ended gauge block interferometers (DEI) are becoming more and more established. This paper suggests its extension for enabling interferometric measurement of diameter topographies of spheres as an alternative to the existing spherical Fizeau interferometers. The extension essentially consists in the addition of two lenses which are as similar as possible, which are arranged symmetrically around the sphere to be measured. The determination of the diameter topography from the interferometric measurements with inserted and without sphere in the extended DEI is derived and specific aspects are discussed. An adjustment strategy for the extended DEI is also suggested. In conclusion, the proposed extension appears to be a promising measurement tool, especially for measuring small spheres, as required for applications in coordinate metrology.
Optical form measurement employing a tiltable line scanning, low coherence interferometer for annular subaperture stitching interferometry
Authors: Schake Markus , Riebeling Jörg , Lehmann Peter , Ehret Gerd
Published: May 2021

This contribution presents experimental and simulation results of a tiltable line scanning low coherence interferometer applied for form measurement of spherical and aspherical objects with a diameter of up to 300 mm. The region of interest is sampled by multiple annular subapertures that are realigned employing stitching algorithms based on Cartesian- and Zernike polynomial fittings. The paper addresses common challenges in the reduction and modeling of displacement errors associated with the motion of the interferometric sensor between subaperture measurements and compares the topography deviations of the experimental results with those simulated by a Monte Carlo based model.
A novel nonenzymatic ascorbic acid electrochemical sensor based on gold nanoparticals-chicken egg white-copper phosphate-graphene oxide hybrid nanoflowers
Authors: Gao Jiaojiao , Liu Hui , Wu Kexin , Yan Jifeng , Tong Cheng
Published: May 2021

Au-CEW-Cu3(PO4)2-GO nanoflowers (HNFs), which were assembled of gold nanoparticals (Au NPs), chicken egg white (CEW), copper phosphate (Cu3(PO4)2) and graphene oxide (GO) together to form a flower-like organic/inorganic hybrid nanocomposite, were synthesized through a simple and gentle one-pot co-precipitation method. The prepared samples were well characterized by scanning electron microscope, transmission electron microscope, energy dispersive x-ray spectrometer, x-ray diffraction and Raman spectrometer. The prepared Au-CEW-Cu3(PO4)2-GO HNFs was used to modify glassy carbon electrode to fabricate an electrochemical sensor for detection of ascorbic acid (AA). The electrochemical test results show that the linear range of the developed sensor is 8–300 μM and the detection limit is 2.67 μM (S/N = 3). While this sensor displays high sensitivity of 6.01 × 10–3
μA μM−1 cm−2 and low detection potential of 35 mV due to the combination of the high conductivity of Au NPs, the larger specific surface area of GO and the intrinsic electrocatalytic activity of CEW-Cu3(PO4)2 HNFs. Moreover, the Au-CEW-Cu3(PO4)2-GO HNFs-based sensor was successfully developed for application in electrochemical detection of AA in vitamin C tablets.
Gold nanorods doping induced performance improvement of room temperature OTFT NO2 sensors
Authors: Hou Sihui , Shao Bingyao , Yu Xinge , Yu Junsheng
Published: May 2021

Solution-processed organic thin-film transistors (OTFTs) are regarded as the promising candidates for low-cost gas sensors due to their advantages of high throughput, large-area and sensitive to various gas analytes. Microstructure control of organic active layers in OTFTs is an effective route to improve the sensing performance. In this work, we report a simple method to modify the morphology of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) thin films via doping gold nanorods (Au NRs) for enhancing the performance of the corresponding OTFT sensors for nitrogen dioxide (NO2) detection. With the optimized doping ratio of Au nanorods, the TIPS-pentacene OTFT snesors not only exhibit a 3-fold increase in mobility, but also obtain a high sensitivity of 70% to 18 ppm NO2 with a detection limit of 270 ppb. The microstructures and morphologies of the modified TIPS-pentacene thin film characterized by atomic force microscopy and field scanning electron microscope. The experimental results indicate that the proper addition of Au NRs could effectively regulate the grain size of TIPS-pentacene, and therein control the density of grain boundaries during the crystallization, which is essential for the high-performance gas sensors.
Suppressing ion migration of CsPbBr
x
I3-x
nanocrystals by Nickel doping and the application in high-efficiency WLEDs
Authors: Yang Supeng , Zhu Hanwen , Xu Enze , Li Junchun , Yang Heming , Zhang Yan , Zhu Zhifeng , Jiang Yang
Published: May 2021

All inorganic perovskite nanocrystals CsPbX3(X = Cl, Br, I) are the great potential candidates for the application of high-performance light emitting diodes (LED) due to their high Photoluminescence Quantum Yield (PLQY), high defect tolerance, narrow full-width half-maximum and tunable wavelength of 410–700 nm. However, the application of red-emitting (630–650 nm) CsPbBr
x
I3-x
nanocrystals are perplexed by phase segregation due to the composition of mixed halides and the difference in halide ion mobility. Herein, we provide an effective strategy to suppressing the migration of Br/I ions through Ni2+ doping via a facile Hot-Injection method and the PLQY was improved as well. DFT calculations show that the introduction of Ni2+ causes a slight contraction of the host crystal structure, which improves the bond energy between Pb and halides and reduces the level of surface defects. Therefore, the phase stability is improved by Ni2+ doping because the phase segregation caused by ion migration in the mixed phase is effectively inhibited. Meanwhile, the non-radiative recombination in the exciton transition process is reduced and the PLQY is improved. What’s more, benefiting from the suppressed ion migration and enhanced PLQY, we combine the Ni2+-doped CsPbBr
x
I3-x
nanocrystals with different Br/I ratios and YAG: Ce3+ phosphors as color conversion layers to fabricate high efficiency WLED. When the ratio of Br/I is 9:11, WLED has a color coordinate of (0.3621, 0.3458), the color temperature of 4336 K and presents a high luminous efficiency of 113.20 lm W−1, color rendering index of 94.9 under the driving current of 20 mA and exhibits excellent stability, which shows great potential in the application of LED.
Radiation-induced magnetoresistance oscillations with massive Dirac fermions
Authors: Iñarrea Jesús , Platero Gloria
Published: May 2021

We report on a theoretical study on the rise of radiation-induced magnetoresistance oscillations in two-dimensional (2D) systems of massive Dirac fermions. We study the bilayer system of monolayer graphene and hexagonal boron nitride (h-BN/graphene) and the trilayer system of hexagonal boron nitride encapsulated graphene (h-BN/graphene/h-BN). We extend the radiation-driven electron orbit model that was previously devised to study the same oscillations in 2D systems of Schrödinger electrons (GaAs/AlGaAS heterostructure) to the case of massive Dirac fermions. In the simulations we obtain clear oscillations for radiation frequencies in the terahertz and far-infrared bands. We investigate also the power and temperatures dependence. For the former we obtain similar results as for Schrödinger electrons and predict the rise of zero resistance states. For the latter we obtain a similar qualitatively dependence but quantitatively different when increasing temperature. While in GaAs the oscillations are wiped out in a few degrees, interestingly enough, for massive Dirac fermions, we obtain observable oscillations for temperatures above 100 K and even at room temperature for the higher frequencies used in the simulations.
Electromagnetic instability analysis of functionally graded tapered nano-tweezers
Authors: Yaghoobi Majid , Koochi Ali
Published: May 2021

Increasing the application of electromechanical nano-tweezers for biological purposes results in new operating conditions such as an external magnetic field. This study deals with investigating the electromagnetic instability of nano-wire manufactured tweezers. To enhance the nano-tweezers’ operating range, a pair of functionally graded nano-wire-based tweezers with linearly varying diameter is considered. The impact of Lorentz forces due to external magnetic flux is simulated by developing Maxwell’s equation. The material distribution along the length of the nano-tweezers arms is modeled based on the power-law distribution. The size-dependent nonlinear constitutive equation of the system is extracted by employing the couple stress theory in combination with Hamilton’s principle. A finite element procedure is proposed to simulate the nano-system and investigate electromechanical instability behavior. The role of influential parameters, including the external magnetic field, the size dependency, material distribution, the Casimir force, and the geometry on the tweezering range and instability voltage of nano-tweezers, are investigated.
Dependence of upstream SOL density shoulder on divertor neutral pressure observed in L-mode and H-mode plasmas in the EAST superconducting tokamak
Authors: Yan N. , Chen L. , Xu G.S. , Wu X.Q. , Liu S.C. , Wang Y.F. , Meng L.Y. , Hu G.H. , Zhao N. , Lan H. , Naulin V. , Nielsen A.H. , Juul Rasmussen J. , Li K.D. , Wang L. , Yang Q.Q. , Li M.H. , Ye Y. , Ding R. , Tao Y.Q. , Qian Y.Z. , Hou J.L. , Liu X. , Liu J.B.
Published: May 2021

Upstream density profiles in the scrape-off layer (SOL) have been examined in low-confinement mode (L-mode) and high-confinement mode (H-mode) plasmas in the EAST superconducting tokamak. A weak density shoulder forms in the near SOL region in upper single-null configurations when the neutral pressure measured at the lower divertor exceeds a threshold value of 2 × 10−2 Pa in L-mode plasmas. When the neutral pressure is below this threshold, the weak density shoulder is absent and the sidebands of the lower hybrid waves associated with SOL parametric instabilities are reduced. Active detachment control with neon–deuterium seeding demonstrate that the weak density shoulder can form before the onset of the outer divertor detachment as long as the neutral pressure is above the threshold. Furthermore, no remarkable expansion of a shoulder is observed during divertor detachment, suggesting that divertor detachment is not a necessary condition for the formation or growth of a density shoulder. Through the increase in neutral pressure in the lower divertor by an order of magnitude, the weak shoulder was observed to expand into the far SOL and reach the leading edge of the limiter. The results in L-mode discharges identified the neutral pressure in the lower divertor as a primary factor for the formation of an SOL density shoulder in the upper single-null discharges. For the type-I ELMy H-mode plasmas, a similar density shoulder was detected during the inter-ELM phase when the neutral pressure in the lower divertor exceeded a threshold value of 4 × 10−2 Pa. On the other hand, the shoulder was absent when the divertor neutral pressure went below this threshold even though the plasma discharge was conducted with a higher core line-averaged density and divertor collisionality. This is consistent with the observations in L-mode plasmas. The neutral particle ionization of the working gas is thus believed to play a key role during the formation of the SOL density shoulder in the EAST tokamak.
Summary of the IAEA technical meeting on plasma disruptions and their mitigation
Authors: Bandyopadhyay Indranil , Barbarino Matteo , Bhattacharjee Amitava , Eidietis Nicholas , Huber Alexander , Isayama Akihiko , Kim Jayhyun , Konovalov Sergey , Lehnen Michael , Nardon Eric , Pautasso Gabriella , Rea Cristina , Sozzi Carlo , Villone Fabio , Zeng Long
Published: May 2021

This report summarizes the contributions presented at the IAEA technical meeting on plasma disruptions and their mitigation, held virtually, 20–23 July 2020. The meeting brought together more than 120 experts from nuclear fusion research sites worldwide to discuss experimental, theoretical and modelling work in the field of plasma disruptions with special emphasis on developing a solid basis for possible disruption mitigation strategies in ITER and next generation fusion devices. The main topics of the meeting were: (i) disruption consequences, including electromagnetic loads, heat loads, and runaway electrons; (ii) disruption prediction and avoidance, including machine learning and physics-based approaches, and control aspects; and (iii) disruption mitigation, including shattered pellet injection, alternative techniques and general aspects of disruption mitigation.
Elaboration of an App for calculations of dosimetric quantities aiming at radiological protection
Authors: Ramos MS , Razuck FB
Published: May 2021

In routine operations of services and standard practices that use ionizing radiation sources, safety is required in relation to the calculations of the variables, according to the operation. The safe distance to operate at, the conversions of units and other important quantities need metrological precision, to avoid any unfortunate unwanted affects. In this sense, this work aims to demonstrate the benefits of an App that can be used free of charge for calculating dosimetric quantities. This App proved to be efficient and accurate in tests, for example, in calculations for Gammagraphy.
Trilateral South American project: a reference system for measuring electric power up to 100 kHz – progress report III
Authors: Kyriazis G A , Di Lillo L , Slomovitz D , Iuzzolino R , Yasuda E , Trigo L , de Souza R M , Laiz H , Afonso E
Published: May 2021

Three countries in South America are jointly developing a reference system for measuring electric power up to 100 kHz. The objective is the construction of three similar measuring systems, one for each institute. This project will contribute to provide calibration services in measuring ranges still not covered by the three institutes both in ac-dc transfer and in electric power. The status of its development by the end of 2019 is described here.
Custom made polymeric artificial eye: Appearance and characteristics of wear and care
Authors: Naji A M , Yaseen M M W , Majali A J , Nief O A
Published: May 2021

A prosthetic eye may enhance the appearance of individuals who have lost sight due to injury or illness. Implanting a polymeric ocular prosthesis (POP) after an eye is surgically removed following an enucleation, evisceration, or orbital exenteration is always advised. This implant supports proper eyelid functioning as well as increasing patient confidence by restoring natural appearance. From February 2013 to January 2019, an experimental study was done on five hundred cases. The included patients experienced enucleation or evisceration procedure and had ocular prosthesis fitting. Data were entered, coded, cleaned, and analyzed using IBM SPSS statistics. A total of 500 cases completed the questionnaire. Of these, 55.8% were male, and 44.2% were female, with 50.2% of the patients lost their eyes because of injuries. In terms of operation variety, evisceration was done in 61.4% of the patients, enucleation in 37.6%, and others are in only five congenital cases (1%). According to this study, 28.8% of patients suffered from deposits formed on the prosthetic eye, while the absence of deposits was 71.2%. Significant psychological, as well as social consequences can result from the disfigurement associated with eye loss. Despite using the available materials and techniques to treat such patients, one needs to be a little creative and very inventive. Ocular prostheses act as a tool for restoring patients’ self-confidence and facilitating changes in their social convenience. Precise attention is essential to preserve the prosthesis and reminiscent of tissue health.
Theoretical study for cellulose and its derivatives toward enalapril into electronic properties by density functional theory
Authors: Merza M M , Al-Ani R R , Hussein F M
Published: May 2021

Current research describes electronic properties for cellulose(CE) and its derivatives (Carboxyl methyl cellulose (CMC), Hydroxy propyl cellulose(HPC), Maliec anhydride cellulose(MAC)) and Enalapril is one of the drugs taking this medicine for high blood pressure. In this research an investigation of an Enalapril drug with cellulose and derivatives by the DFT/B3LYP method, Hartree-Fock (HF) method with basis set (STO-3G,6-31G++(d,p)using) for phallic index and other parameters. The results dealing of Enalapril drug with carries including optimized geometrical structure, activation energy, heat of cracking (ΔHc), dipole moment. The NLO properties and biological activity by depended on chemical parameter studied that including (HOMO-LOMO) from the theoretical results for prodrugs that can use as several carries.
Design & Development of Integrated Information Management System for Drilling Operations Abroad
Authors: Wang Liupeng , Chang Du , Peng Yuanchao , Dang Wenqing
Published: May 2021

Due to the limitation of cooperation contract period, logistics supply and regional conditions, the number of drilling rigs and drilling operation procedures need to be arranged scientifically and reasonably for drilling operations abroad. According to the characteristics of this foreign drilling operation, we design and develop an Integrated Information Management System (IIMS) including intelligent planning and integrated management system including well site data management, office work planning and cost control, operation management, statistical query and logistics support.
Research on Three Dimensional Global Path Planning of Unmanned Underwater Vehicle
Authors: Hu Zhiyuan , Wang Zheng , Yin Yang
Published: May 2021

The ant colony algorithm is used to solve the global path planning problem of unmanned underwater vehicle (UUV) in three-dimensional environment. On the basis of grid model environment, the traditional ant colony algorithm is optimized. In order to meet the needs of path planning, an improved algorithm is proposed to solve the problem of initial pheromone distribution. Simulation results show that the improved ant colony algorithm has the characteristics of fast convergence.
Comparison Study of Leading Rotary Steerable System and Future Development Trend
Authors: Fei Li , Xue-ying Ma , Yu-qi Tan
Published: May 2021

The rotary steerable system is critical drilling equipment urgently needed in the development of unconventional oil and gas fields in China. It is still a significant but unavailable technology for China’s petroleum industry. With the high demand for rotary steerable system in unconventional oil and gas development, this paper studies RSS tools from major oilfield service companies. Different tools from major oilfield service companies and their technical specifications were studied. Firstly, the development history of the rotary steerable system is introduced, and the tools are then classified into different categories based on control and biasing methodologies. The key technical parameters of the RSS were compared and analyzed. Moreover, a detailed comparison of the 475, 675 and 900 series of tools has been carried out. The current development focuses of rotary steerable tools include high dogleg severity, high temperature and high pressure and integrated navigation scheme with inertial and magnetic methods. Finally, the development trends of the RSS were forecasted. The objective of this paper is to provide an overview and latest development of the rotary steerable system for developer, operation and maintenance population in the drilling industry.
Application of the Indoor Large-length Standard Device
Authors: Hu Chang’an , Lv Fei , Luo Shutong , Yang Zhuang , Zhang Rui , Li Wanze
Published: May 2021

The indoor large-length standard device is a comprehensive standard for traceability of large-length measurement value. It provides that the standard ensures its accuracy and reliability in the effective detection range. In order to ensure the accuracy of the quantity traceability of the large-length measuring instrument, we independently developed the domestic first set of metal linear guide indoor large-length standard device in the southwest. The high-precision metal linear guide cooperating with precision gear rack transmission is used in this device. The main drive system with an independent position closed-loop control is employed to eliminate effectively the influence of a series of problems, including the unstable floating track deformation and loss of friction wheels, difficult maintenance. The device can also hold an accurate and reliable statue throughout the execution, which can also maintain stable acceleration and velocity and has the advantages of no vibration transmission system, automatic operation. The measuring range of the device is (0∼56) m, and the uncertainty of measurement is U=0.14um+10−7L (k=2). Its function is mainly used to carry out the distance meter, laser interferometer, laser tracker, standard steel tape equipment, and terrestrial laser scanner; also the device can also be used for linear displacement sensors, liquid level measuring devices, standard baseline feet, and other non-standard class length equipment calibration.
Autonomous Obstacle Avoidance Scheme Using Monocular Vision Applied to Mobile Robots
Authors: Song Yun Yun , Yang Sheng Yi , Liu Chao , Wu Qing Gui
Published: May 2021

Mobile robots cannot move in an unknown environment with static or slow-moving obstacles effectively. We present an enhanced obstacle avoidance strategy using monocular vision to solve this problem. First, we combine Canny and Otsu to extract the barrier feature and find the critical pixel position of obstacles by the monocular vision. Then the image depth estimation algorithm is used to estimate the gaps. With these parameters of barriers, an improved bug algorithm is proposed to avoid the obstacles autonomously. The experiments show that the proposed obstacles avoidance strategy can effectively make a small mobile robot avoid different kinds of obstacles.
Intelligent coalbed methane production management and control technology based on reinforcement learning algorithm
Authors: Hongli Wang , Suian Zhang , Bin Liu
Published: May 2021

The production control of coalbed methane wells has long been viewed as the most challenging step in its development process. For human engineers, they rely too much on previous experience. For artificial intelligence, there is no complete frame to use. Here we proposed a system with reinforcement learning algorithm to CBM production control optimization that used a proxy model to simulate the gas and water seepage in coal seam, and a ‘value networks’ to evaluate gas and water production capability and three control policy mode: bottomhole pressure (BHP) regression model, BHP reduction rate mode, BHP table to select moves. The system achieved a 20.99% and 38.14% increment in cumulative gas and water production, respectively.
Sliding Mode Variable Structure Control of the Steerable Drilling Stabilized Platform Based on Disturbance Observer
Authors: Huo Aiqing , Zhang Shuhan , Wu Shilei
Published: May 2021

A sliding mode variable structure control based on disturbance observer (SMVSCDOB) has proposed to tackle the uncertainty caused by friction in the stabilized platform on the rotary steerable drilling. Disturbance observer (DOB) is used to estimate the uncertainty in stabilized platform, and the estimated value is compensated by sliding mode variable structure control (SMVSC) to improve the control accuracy. The simulation experiment of control system is carried out with MATLAB, comparing the SMVSCDOB control method with proportional integral derivative (PID), PID+DOB, SMVSC. The simulation results show that the proposed method SMVSCDOB can better track the tool face angle, reduce the system error, suppress the friction interference, and enhance robustness of the system.
Active disturbance rejection control of indoor inspection robot in intelligent substation based on monocular vision
Authors: Chen Dekai
Published: May 2021

In order to improve the autonomous digging ability of the inspection robot, an auto disturbance rejection control method based on monocular vision is designed for the indoor inspection robot in the intelligent substation. Through tracking and detecting the end position and posture changes of the robot in the x-z plane during the operation of the robot in the intelligent substation, and mining the abnormal data, and combining with the PID control principle, the inspection robot single view automatic disturbance rejection control method is designed The visual interference information is cleaned and denoised to realize the auto disturbance rejection and autonomy of the indoor inspection robot monocular vision pan-tilt. Due to the adjustment of the operating parameters of the pan-tilt active disturbance rejection controller based on monocular vision of the indoor inspection robot, it is difficult to set the parameters due to the interaction between the parameters. Furthermore, the parameters of the ADRC are adjusted and optimized to meet the research requirements of the effective control of the pan-tilt active disturbance rejection of the indoor inspection robot in the substation. Finally, the experimental results show that compared with the traditional methods, the control accuracy and strong robustness of the indoor inspection robot in the substation are significantly improved, which fully meets the research requirements.
Design and Implementation of Drilling Engineering Simulation System Based on Unity3D
Authors: Huo Aiqing , Xu Jingrong , Li Haoping , Wang Zewen
Published: May 2021

In this paper, a drilling engineering simulation system is designed and developed aiming at some problems existing in traditional well control safety operation training. The overall design and process of the virtual simulation system were given, optimized and rendered the models of the drilling engineering equipment and the wellsite scene were created using the software 3Ds Max. With the aid of the Unity3D development platform, the oil drilling virtual simulation system was constructed, which realized the interaction between the wellsite roaming system and drilling operations. The system has the characteristics of low development cost, strong real-time interaction, realistic immersion and meets the needs of oilfield drilling engineering training.
Fault diagnosis of fracturing truck based on ITD and TET
Authors: Zhong Xinrong , Chai long , Che Haoyang , Zhao ZhiChuan
Published: May 2021

The power system is the core part of fracturing truck, and its running state will directly determine the operation efficiency of fracturing truck. Fracturing trucks often operate under heavy load and noisy conditions, so the power system is prone to faults and difficult to diagnose. In order to solve the difficult problem of fracturing vehicle power system diagnosis under noise and changing working conditions, one method based on intrinsic time-scale decomposition (ITD) and transient-extracting transform (TET) is proposed. Firstly, using the intrinsic time-scale decomposition to dealing the collected vibration signal of the fracturing vehicle power system, multiple related components have been obtained, and then perform transient-extracting transform to processing the components with larger correlations to the original signal. The local features of the signal are enhanced and the fault features are extracted to complete the fault diagnosis. The test results showing that the proposed fault diagnosis method can accurately identify the fault condition of the power system. the conclusions obtained can provide a certain reference for the research and development of the power system fault diagnosis method of fracturing truck.
Intelligent Human Body Posture Recognition and Its Comparative Study
Authors: Wang Zheng , Zhang Long-fei , Feng Xiao-xing , Liu Meng-xi
Published: May 2021

An algorithm of activity pattern recognition based on fuzzy mathematics used the excellent characteristics and the classification ability of multiple classifier for human pasture identification is analyzed and compared. Time-domain analysis is used as the only method through large amounts of data, and corresponding BP neural network and Support vector machine (SVM) was established were compared with the algorithm of fuzzy mathematics, and some method were evaluated at last. The results showed that the algorithm based on fuzzy mathematics had a good performance and value.
Study on determining the dominant flow path of oil reservoir by static data
Authors: Wenjie Zhao
Published: May 2021

Block A is a 2016-2017 production block. After infilling, block 1,2 and 3 are divided into three segments, block 4 is divided into two segments, block 4 is divided into two segments, and block 4 is not divided into segments, that is, Gaotaizi first segment. With the increase of well pattern density and the increase of vertical upper strata, the whole injection-production relationship becomes more complex and the dynamic adjustment is more difficult. By integrating the static data, we can determine the dominant wells and the dominant zones among the well groups, and find out the dominant channel of each zone by comparing the seepage capacity in each direction of the water coming from the sub-zone. To further subdivide the connecting types, and finally determine the dominant channel of each sedimentary unit by combining the reservoir thickness, well spacing and source direction. For the case of multiple well patterns interacting with each other, aiming at the sections of the dominant wells and formations which are in the front of the sequence and are easy to be overinjected. For the interval in the middle of the sequence of dominant wells and formations, the water injection volume fluctuates frequently and needs to be checked and matched. For the interval in which the sequence of dominant wells and formations is backward, the measures of increasing injection are adopted. It has important guiding significance for efficient development of Gaotaizi reservoir in the later stage of ultra-high water cut.
Application of High Resistance Operational Amplifier CA3140A in Signal Conditioning Circuit of Gamma Logging Tool
Authors: Tian Xiaochao
Published: May 2021

The current type signal of gamma detector in gamma logging tool is generally weak, which can not be directly input into microcontroller for pulse counting and statistical analysis. The signal conditioning circuit is designed by using high performance, low noise, small volume single operational amplifier CA3140A, which processes the weak signal from gamma detector, and realizes the corresponding hardware circuit according to the actual application requirements. The experimental results show that: the circuit design performance is stable, and can effectively pick up and process the effective pulse signal, which meets the expected design requirements.
The Establishment of a Drilling Rate of Penetration Prediction Model Based on GA-BP
Authors: Qi Li , Wei Zhang , Cong Xie
Published: May 2021

The prediction of ROP is the key to optimization and control of drilling engineering. The lack of application of actual engineering data in existing theoretical models makes it difficult to meet field requirements. This paper establishes a new model for predicting ROP, which combines artificial intelligence algorithms and neural networks. First, the wavelet filtering method is used to reduce the noise of the measured data the measured data at the drilling site, and the input parameters of the ROP prediction model are optimized according to the mutual information correlation analysis to reduce the model redundancy. Secondly, the genetic algorithm (Genetic Algorithm) is used to optimize the initial weights and thresholds of the BP neural network, thereby establishing a new ROP prediction model. The final results show that GA-BP has stronger convergence and search ability and better calculation accuracy.
Field Test of Vibration Wave Attenuation Coefficient Model in Casing Medium
Authors: Zhang Xiaobin , Yang Quanzhi , Xu Feiyan , Li Wenhong , Li Weifeng , Hou Yunyi
Published: May 2021

The casing string is a very good down-hole signal transmission channel due to its rigidity which means it can reduce attenuation in vibration wave propagation. Based on elastic mechanics theory, we obtain the wave equations of vibration propagating in the free casing, analyze the transmitting law of the vibration wave in the well fluid-casing-cement system and found that the attenuation of the vibration wave is mainly caused by the energy absorbed including the well fluid, the casing and the cement ring. Based on the attenuation factors which affect the wave propagation, we get the vibration wave attenuation coefficient model and calculate the relative attenuation coefficients in different casing strings. By detecting and analyzing the drilling plug signal in the second spud, the field test results prove the feasibility of long-distance transmission and the low attenuation of vibration wave in the casing string, and get the attenuation coefficient of casing size 9 5/8, which is similar to the simulation result.
Real-time monitoring and early warning of well leakage based on big data analysis
Authors: Yingzhuo Xu , Liupeng Wang , Yang Zhang , MingZhen Li
Published: May 2021

In petroleum drilling engineering operations, complex lost circulation accidents not only affect the efficiency of drilling operations, but serious lost circulation may cause wellbore failure. The occurrence of lost circulation accidents is affected by various factors such as formation conditions, engineering parameters, and operating dynamic parameters. The conventional focus of lost circulation research is to analyze the mechanism of lost circulation, but the data such as engineering parameters and operating dynamic parameters when lost circulation occurs are insufficiently utilized. At present, the field of drilling engineering has accumulated a large amount of historical drilling data, and the complicated occurrence of lost circulation accidents often has regional statistics. How to use big data technology to establish the correlation model between lost circulation and parameters, reason and analyze the main influencing factors of lost circulation, then use the established correlation model comparative analysis. After the data model comparative analysis, it can make different specifications of responses and early warnings for data anomalies with different weights, so as to reduce the impact on drilling operations while avoiding lost circulation accidents.
DOA Estimation Based on Average Processing of Redundant Virtual Array Elements for Coprime MIMO Radar
Authors: Zhang Yule , Hu Guoping , Zhu Mingming , Zhan Chenghong , Zhao Feilong , Zhou Hao , Zhao Fangzheng , Yue Shijie
Published: May 2021

The redundant virtual array elements formed by the sum and difference coarray (SDCA) are always discarded in the existing DOA estimation methods, which could cause effective information loss and poor performance. In this paper, a new technology based on average processing of redundant virtual array elements is proposed for coprime MIMO radar direction of arrival (DOA) estimation. Then, Toeplitz matrix reconstruction based on MUSIC algorithm is employed to validate the effectiveness of the proposed technology for DOA estimation.
The Mathematic Model Study of Optimum Align Method in Compass
Authors: Weifeng Li , Xiaolong Yu , Yan Wang
Published: May 2021

In this paper, based on the study of the characteristics of horizontal well designed by optimum align method in compass software, we speculated that, the optimum align method is one kind of space circular arc method. Therefore, we built a horizontal well track design model based on spatial arc curve optimization alignment hypothesis. The orbit design problem of horizontal wells is transformed into the problem solving of multiple linear equations with trigonometric functions. If the kick off point, the target point and the dog leg degree of the first and second inclined sections are determined, the solution of the track parameters of the horizontal well is unique, and the track parameters of the horizontal well can be calculated accurately. The model result is the same as the optimum align method in compass program. Therefore, the algorithm essence of Compass Optimum Align design method is to solve the problem of multiple linear equations based on the optimal alignment of arc curves in space.
Multi-classifier Combined Anomaly Detection Algorithm Based On Feature Map In Underground Coal Mine
Authors: Fu Yan , Cui Zemin , Ye Ou
Published: May 2021

The detection of abnormal activities in deep learning is of great significance for preventing the occurrence of abnormal disasters in mine production. As the underground scenes of coal mines are characterized by much noise and uneven light, the traditional manual feature extraction method has little obvious effect in the underground and low accuracy of anomaly detection. To solve the above problems, a feature extraction method combining CNN+LSTM is proposed. Secondly, the obtained features are matched by graph structure. Finally, multiple classifiers are used to classify the features before and after matching. In this paper, experiments are carried out in coal mine dataset and UCSDped1 dataset respectively, and comparisons are made with some classical algorithms. Experimental show that the algorithm achieves high recognition accuracy in different abnormal event datasets.
Prediction of Submarine Pipeline Corrosion Based on the Improved Grey Prediction Model
Authors: Gao Jianfeng , Hao Bin
Published: May 2021

To predict the degree of corrosion and remaining life of submarine pipelines more accurately, and to prevent pipeline leakage accidents caused by the pipeline corrosion in advance, an improved grey model that applies appropriate translation and sine transformation to the original series was established. And the initial value of the time-corresponding function was optimized when the model was solved. Compared with the two grey models mentioned in the paper, the accuracy of the improved grey model has been improved, and the stability of the model was better. The result shows that the prediction result of the improved grey model is closer to the measured value.
The design of Optical Stochastic Cooling for IOTA
Authors: Lebedev V. , Jarvis J. , Piekarz H. , Romanov A. , Ruan J. , Andorf M.
Published: May 2021

The paper presents a journal version of the Design Report on
the Optical Stochastic Cooling experiment to be carried out at IOTA
ring in Fermilab later this year. It discusses the theory which
experiment is based on, beam parameters, major requirements to the
storage ring systems and technical details of the experiment
implementation.
Embedding stakeholders’ priorities into the low-emission development of the East African dairy sector
Authors: Yesuf Gabriel U , Schoneveld George C , Zijlstra Mink , Hawkins James , Kihoro Esther M , Vernooij Vera , Rufino Mariana C
Published: May 2021

A growing body of evidence shows that more intensive dairy systems can be good for both nature and people. Little research considers whether such systems correspond with local priorities and preferences. Using a mixed methods approach, this study examined the effects of three intensification scenarios on milk yield and emission intensities in Kenya and Tanzania. Scenarios included (a) an incremental change to feed management; (b) adaptive change by replacing poor quality grass with nutrient-rich fodder crops; and (c) multiple change involving concurrent improvements to breeds, feeds and concentrate supplementation. These scenarios were co-constructed with diverse stakeholder groups to ensure these resonate with local preferences and priorities. Modelling these scenarios showed that milk yield could increase by 2%–15% with incremental changes to over 200% with multiple changes. Greenhouse gas emission intensities are lowest under the multiple change scenario, reducing by an estimated 44%. While raising yields, incremental change conversely raises emission intensities by 9%. Our results suggest that while future interventions that account for local priorities and preferences can enhance productivity and increase the uptake of practices, far-reaching shifts in practices are needed to reduce the climatic footprint of the dairy sector. Since top-down interventions does not align with local priorities and preferences in many situations, future low-emission development initiatives should place more emphasis on geographic and stakeholder heterogeneity when designing targeting and implementation strategies. This suggests that in low-income countries, bottom-up approaches may be more likely to improve dairy productivity and align with mitigation targets than one-size-fits-all approaches.
Decreased soil moisture due to warming drives phylogenetic diversity and community transitions in the tundra
Authors: Scharn Ruud , Little Chelsea J , Bacon Christine D , Alatalo Juha M , Antonelli Alexandre , Björkman Mats P , Molau Ulf , Nilsson R Henrik , Björk Robert G
Published: May 2021

Global warming leads to drastic changes in the diversity and structure of Arctic plant communities. Studies of functional diversity within the Arctic tundra biome have improved our understanding of plant responses to warming. However, these studies still show substantial unexplained variation in diversity responses. Complementary to functional diversity, phylogenetic diversity has been useful in climate change studies, but has so far been understudied in the Arctic. Here, we use a 25 year warming experiment to disentangle community responses in Arctic plant phylogenetic β diversity across a soil moisture gradient. We found that responses varied over the soil moisture gradient, where meadow communities with intermediate to high soil moisture had a higher magnitude of response. Warming had a negative effect on soil moisture levels in all meadow communities, however meadows with intermediate moisture levels were more sensitive. In these communities, soil moisture loss was associated with earlier snowmelt, resulting in community turnover towards a more heath-like community. This process of ‘heathification’ in the intermediate moisture meadows was driven by the expansion of ericoid and Betula shrubs. In contrast, under a more consistent water supply Salix shrub abundance increased in wet meadows. Due to its lower stature, palatability and decomposability, the increase in heath relative to meadow vegetation can have several large scale effects on the local food web as well as climate. Our study highlights the importance of the hydrological cycle as a driver of vegetation turnover in response to Arctic climate change. The observed patterns in phylogenetic β diversity were often driven by contrasting responses of species of the same functional growth form, and could thus provide important complementary information. Thus, phylogenetic diversity is an important tool in disentangling tundra response to environmental change.
Defect-induced anticorrelations in molecular motor traffic
Authors: Schütz G M
Published: May 2021

We revisit the nonequilibrium phase transition between a spatially homogeneous low-density phase and a phase-separated high-density state in the deterministic sublattice totally asymmetric simple exclusion process with stochastic defect. We discuss this phase transition in a grandcanonical ensemble for which we obtain exact results for the stationary current-density correlations and for the average collective velocity. We identify defect-induced anticorrelations that are absent in similar boundary-induced phase transitions. The average collective velocity vanishes at the phase transition and in the phase-separated state due to its macroscopic spatial inhomogeneity.