bluuebunny/crossref_metadata_2025 huggingface dataset:
Using a mixture of vinasse-contaminant and H3PO4 as an efficient electrolyte for high performance flexible carbon nanotube-based supercapacitors
Authors: Mendoza R , Rodriguez-Gonzalez V , Zhakidov A A , Cherepanov S , Mtz-Enriquez A I , Oliva J
Published: May 2021

The elimination of vinasse contaminant generated by the tequila industry and other alcoholic beverages is of current interest because millions of liters are produced every year and it cannot be released in the environment due to its low pH and high content of organic material. As an effort to reuse/recycle such a contaminant, we report the use of a mixture of vinasse-contaminant + H3PO4 as the electrolyte for flexible supercapacitors (SCs), which are made with carbon nanotube (CNT) electrodes. We obtained a high capacitance value of 679.7 F g−1 in the devices made with both electrodes of CNTs. When the Ag/TiO2 nanoparticles are added in the SC anode, the capacitance is enhanced to 1852.8 F g−1, which is among the highest values reported so far for flexible CNT based SCs. We also compared the performance of the SC made with vinasse to another made with a conventional electrolyte of PVA/H3PO4 and found that the capacitance and energy density values of this last device were 1.2 times lower. All the devices made with CNTs, Ag/TiO2 and vinasse + H3PO4 stored charge by redox reactions and the redox centers were: oxygen vacancies, carboxylic groups, Ag0/Ag2+ and Ti3+/Ti4+ ions. Thus, the vinasse contaminant is a feasible electrolyte for supercapacitors.
Flavor triangle of the diffuse supernova neutrino background
Authors: Tabrizi Zahra , Horiuchi Shunsaku
Published: May 2021

Although Galactic core-collapse supernovae (SNe) only happen a few times per century, every hour a vast number of explosions happen in the whole universe, emitting energy in the form of neutrinos, resulting in the diffuse supernova neutrino background (DSNB). The DSNB has not yet been detected, but Super-Kamiokande doped with gadolinium is expected to yield the first statistically significant observation within the next several years.
Since the neutrinos produced at the core collapse undergo mixing during their propagation to Earth, the flavor content at detection is a test of oscillation physics.
In this paper, we estimate the expected DSNB data at the DUNE, Hyper-K and JUNO experiments which when combined are sensitive to all different neutrino flavors.
We determine how well the flavor content of the DSNB will be reconstructed in the future, for a Mikheyev-Smirnov-Wolfenstein (MSW) scenario as well as a neutrino decay scenario. A large fraction of the flavor space will be excluded, but the heavy-lepton neutrino flux remains a challenge.
Possible bump structure of cosmic ray electrons unveiled by AMS-02 data and its common origin along with the nuclei and positron
Authors: Zhang Pei-pei , Qiao Bing-qiang , Liu Wei , Cui Shu-wang , Yuan Qiang , Guo Yi-qing
Published: May 2021

The local pulsar and its progenitor, SNR, can together accelerate the positron, electron and nuclei to very high energy. The famous excesses of positron(nuclei) above 20(200) GeV possibly come from such kind of local source. This hints that the primary electron should also hold “excess” above 200 GeV, synchronously accelerated along with the nuclei. The recent precise measurement of sharp dropoff at 284 GeV of positron by AMS-02 experiment takes chance to study this expected electron excess. In this work, the spatially-dependent propagation with a local source is used to reproduce the spectrum of positron, electron and proton. When considering the dropoff at 284 GeV of positron, a sharp bump structure for primary electron above 284 GeV is required to fit the total spectrum of positron and electron. Then we systematically study the common origin of the excesses of positron, electron and nuclei from Geminga pulsar and SNR. Those excesses can be reproduced under this unified single-source model. Lastly, we hope that the fine bump structure can be observed to support our model by AMS-02 experiment in future.
Characterizing Atmospheres of Transiting Earth-like Exoplanets Orbiting M Dwarfs with James Webb Space Telescope
Authors: Gialluca Megan T. , Robinson Tyler D. , Rugheimer Sarah , Wunderlich Fabian
Published: May 2021

A number of transiting, potentially habitable Earth-sized exoplanets have recently been detected around several nearby M dwarf stars. These worlds represent important targets for atmospheric characterization for the upcoming NASA James Webb Space Telescope (JWST). Given that available time for exoplanet characterization will be limited, it is critically important to first understand the capabilities and limitations of JWST when attempting to detect atmospheric constituents for potentially Earth-like worlds orbiting cool stars. Here, we explore coupled climate-chemistry atmospheric models for Earth-like planets orbiting a grid of M dwarf hosts. Using a newly-developed and validated JWST instrument model—the JWST Exoplanet Transit Simulator—we investigate the detectability of key biosignature and habitability indicator gaseous species for a variety of relevant instruments and observing modes. Spectrally resolved detection scenarios as well as cases where the spectral impact of a given species is integrated across the entire range of an instrument/mode are considered and serve to highlight the importance of considering information gained over an entire observable spectral range. Our results indicate that detectability of gases at individual wavelengths is overly challenging for JWST but integrating the spectral impact of a species across the entire wavelength range of an instrument/mode significantly improves requisite detection times. When considering the entire spectral coverage of an instrument/mode, detections of methane, carbon dioxide, oxygen and water at signal-to-noise ratio 5 could be achieved with observations of several tens of transits (or less) for cloud-free Earth-like worlds orbiting mid- to late-type M dwarfs at system distances of up to 10–15 pc. When compared to previous results, requisite exposure times for gas species detection depend on approaches to quantifying the spectral impact of the species as well as underlying photochemical model assumptions. Thus, constraints on atmospheric abundances, even if just upper limits, by JWST have the potential to further our understanding of terrestrial atmospheric chemistry.
Processing and analysis of freeform implants obtained by additive manufacturing from MRI data
Authors: Piratelli-Filho A , Arencibia R V , Silva-Junior J F
Published: May 2021

This work introduces the processing steps for manufacturing implants in substitution of human body parts based on additive manufacturing. The parts were designed with data from Magnetic Resonance Imaging (MRI) of a defective cranium and the deviation analysis of the cranial implants was carried out to characterize the process. At the initial stage, the results of MRI exam of a defective patient’s skull were downloaded from internet in DICOM format. Next, segmentation was applied to separate the soft tissues from the bone one of the MRI data. The cranium bone CAD model was created and implemented in a 3D printer to manufacture the part in polymeric material. The produced part was measured in a 3D laser scanner to collect a surface cloud of points and the quality was evaluated by comparing data points with CAD model. Descriptive statistical analysis was applied to determine the behavior of the deviations. A statistical filter was proposed to remove the outliers using the boxplot graph and the filtered sample was analyzed again to define the statistical parameters of the implant surfaces. The proposed methodology is recommended to characterize the deviations of cranium implants manufactured by additive manufacturing and the determined deviations allow the execution of cranial surgeries with a minimal intervention of the surgeon.
Analysis of Myoelectric Signals to Prosthesis Applications
Authors: Morais B S , Nogueira S L , Russo T L , Santos G L , Salazar L F G , Montagnoli A N
Published: May 2021

This work presents a myoelectric system measurement incorporated in an arm band device, particularly designed for application in upper-limb myoelectric prosthesis with pattern recognition-based sEMG control. For this particular use, specifications such as low cost, high sampling frequency, size and weight, may be observed. Moreover, it is introduced an acquisition protocol to evaluation of the myoelectric signal in daily activities.
Virtual instrument for estimation of HVAC and HVDC test parameters according to IEC 60060-1:2010
Authors: Oliveira Yuri Reis , Silva Márcio Thelio , Barbosa Carlos Roberto Hall
Published: May 2021

High and ultra high voltage tests are commonly carried out to determine external and internal dielectric performances of electric power equipment. The standardization of these tests in different laboratories is obtained by following the standards with the requirements necessary to perform the tests. Among such requirements, the test voltage parameters must be measured within acceptable uncertainties. For a correct analysis of the test and presentation of the results it is necessary that the measuring system and the instrument used be able to estimate all parameters according to standard IEC 60060-1:2010, depending on each type of voltage and test, AC, DC or impulse. However, simpler conventional instruments, such as multimeters, are not capable of measuring and indicating all parameters required by current standards. Thus, dedicated instruments and software are needed, capable of performing the analysis of these parameters within the acceptable uncertainty limits. The use of software or measurement algorithms for voltage impulse testing is already described in IEC 61083-1 and -2 standards. Specifically, part 2 presents the reference waveforms used for the validation of the software used in the tests. Similarly, IEC 61083-4 is being developed for high voltage AC and DC tests, with standard waveforms for validation of the measurement software. The objective of this work is presenting the HVAT AC-DC virtual instrument developed in LabVIEW environment, capable of estimating the required AC and DC test parameters of the ABNT NBR IEC 60060-1:2013 standard and analyzing the robustness of such a virtual instrument through low and high voltage tests.
Evaluation of salbutamol in pure form and pharmaceutical formulations using spectrophotometry and green nonionic surfactant of cloud point extraction
Authors: Thani M Z , Dadoosh S A , Abdullah A M , Fahad A S , Fahad Y S , Faraj F L
Published: May 2021

The purpose of the study was to identify a quick, simple and sensitive spectrophotometric technique for the assessment of salbutamol (SAL). The proposed approach depends on SAL’s azo-coupling reaction with BEN. The orange color of the reaction product was analyzed at λmax (480 nm) against a blank solution. It was obeyed to beer-lambert show over concentration between (2.5-17.5 mg.L−1) with LOD (1.283 mg.L−1), LOQ (4.234 mg.L−1) and molar absorptivity (12922.74 L.mol−1.cm−1). The procedure revealed high sensitivity for assessment of chosen drug. The new cloud point extraction technique was also successfully utilized for the extraction of pharmaceutically pure SAL drug, (also known as 2-[4-(2,4,4-trimethylpentan-2-yl) phenoxy] ethanol), was selected as green extraction solvent due to its properties and structure. The influence of various parameters, such as the kind and volume of surfactant, salt, temperature and incubation time on the CPE of salbutamol was investigated in detail and a set of perfect conditions was established. A correlation coefficient (R2) was 0.9914 for the calibration curve was obtained. The LOD, LOQ and molar absorptivity were 0.041 mg.L−1, 0.12 mg.L−1 and 47024.61 L.mol−1.cm−1, respectively. We believe that our suggested method is rapid, very convenient, and cost effective for the determination of salbutamol drug in the various samples.
Role of Caspase-3, IL-1β and oxidative stress in Iraqi women with breast cancer
Authors: Al-Musawi A K , Al-Rubae’i S H N , Mahdi M F
Published: May 2021

Breast Cancer is caused by malignant tissue cells and has become one of the world’s biggest medical problems. The goal of this research was to determine the serum concentration of markers of oxidative stress that play an important role in the multiple factors involved in breast cancer development, growth, and invasion. Serum of 90 women patients (45 breast cancer and 45 benign breast tumors) and 42 healthy individuals as control group were used in this study. Serum level of MDA, PC, 8-OHdG, IL-1β and Caspase-3 were measured by ELISA. Highly significantly increased levels (p<0.01) of MDA, PC, 8-OHdG, IL-1β and Caspase-3 were found in breast cancer and benign breast tumor when compared to healthy controls. The MDA and Caspase-3 level are considered strong parameters to diagnose and detection for breast cancer using the ROC curve. High lipid peroxidation is a significant risk factor for breast cancer and the activation of apoptosis and pro-inflammatory activity may be due to elevated levels of IL-1β & Caspase-3 in breast cancer cells. Nonetheless, lipid peroxidation and Caspase-3 are major factors in breast cancer growth and progression.
Research on control strategy of electric vehicle under braking state based on fuzzy control
Authors: Shi Yuanlin , Lu Xiuhe , Zhang Tao , Zheng Ruize
Published: May 2021

Aiming at how to improve the efficiency of pure electric vehicles in the process of braking energy recovery and security problems, this paper takes brake laws ECER13 curve and ideal braking force distribution curve as constraint conditions, to design a kind of input is braking intensity z, battery SOC charge ratio, output for mechanical brake than kp, electric braking is larger than that of ki fuzzy control strategy, and with the fuzzy control strategy as the core to establish the model of regenerative braking, this model embedded in the ADVISOR of pure electric vehicles in the model, and the simulation under the condition of circulating CYC_UDDS. The results show that under the fuzzy control strategy, the effective recovery rate of regenerative braking energy increases by 5.4%, and the energy utilization rate of the vehicle increases by 1.9%.
Design of Half-bridge Bidirectional DC-DC Converter Control Loop
Authors: Cheng Huan , Guo Yingna , Ma Zhao , Bai Sisi
Published: May 2021

In recent years, the direct current (DC) microgrid system has received extensive attention from industrial and academic circles worldwide. As an essential part of the DC microgrid, the bidirectional DC-DC converter can realize the bidirectional flow of energy according to the needs of the DC microgrid. In this paper, the half-bridge bidirectional DC-DC converter is taken as the research object, and the double closed-loop feedback control loop of the converter in the charging and discharging mode is designed based on the intermittent and fluctuating characteristics of distributed generation. Besides, a simulation model is built using MATLAB to analyze the operation of the converter in different modes and the control effect of the double closed-loop feedback control loop. The results verify the effectiveness and feasibility of the proposed control method.
Exploration and application of small well spacing development management mode in oilfield
Authors: Zhuo Wang
Published: May 2021

The oil field enters the stage of ultra-high water cut development, especially after the third infilling, the well spacing is small. The water injection advances quickly, the water cut rises quickly, the control of natural decline becomes more and more difficult. According to the traditional oil field development management method, the oil field steady production difficulty will increase continuously. Therefore, we must constantly explore new methods of oilfield development to improve the quality and benefit of oilfield development.
Study on the law of Ultrasonic Wave Plugging
Authors: Yuzhen Liu
Published: May 2021

In the Chang Yuan area of Daqing oilfield, the field test of ultrasonic oil layer removal is carried out in the oil layer with different physical properties, different dynamic conditions and different water quality conditions. We evaluated the overall effect of ultrasonic remove near wellbore plugging, the system of technology parameters and reservoir static parameters, the dynamic parameters and quality of production of ultrasonic lift effect of near wellbore blockage, and ultrasonic, chemical plugging effect comparison. The test results show that the field parameters, static parameters of the reservoir and the dynamic parameters of production all affect the effect of ultrasonic plugging. The total processing time is longer, the better; layer selection priority Portuguese group two and senior group; under the same conditions, priority maximum permeability and small coefficient of variation, a small number of small, high strength injection layers; reservoir pollution, ultrasonic plugging treatment sooner the better. The initial injection efficiency of the two ways of chemical agent and ultrasonic wave is close, and the effective period of the plugging well is longer than that of acidizing well. Under the condition that the production cost of oil field is more and more precise, ultrasonic plugging and unmoving string, short construction time and long effective period can be used as a conventional plug removal method in oilfield application.
Research on calibration test technology of Multi-component force sensor
Authors: Liu SIbo , Qin Haifeng , Liu Yonglu , Chen Wei
Published: May 2021

Multi-component force sensor is a common force measurement instrument that can perceive all six force values and torque values in space. It is mainly used in aerospace, equipment manufacturing and other fields. At present, the calibration of multi-component force sensor is mainly carried out in professional measurement laboratory with special measuring equipment. In the field of measurement and control, the stress condition of multi-component force sensor is very complex, and the sensitivity obtained by calibration test often has certain deviation from the sensitivity of multi-component force sensor under actual load condition. This paper analyzes and tests the common problems of the multi-component force sensor in the actual measurement, control and calibration test. The test proves that the combined loading and loading order and loading position of the multi-component force sensor will affect its sensitivity output. It is necessary to pay attention to the related influence in the use of multi-component force sensor and design the calibration scheme according to the specific loading situation.
Application of Frequency Domain Dielectric Response Method in Intelligent Location of Oil Paper Insulation Bushing Damp Fault
Authors: Wu Jing , Zhang Shaoming
Published: May 2021

Oil paper insulating bushing is widely used in 500 kV and above power transformers. In order to quantitatively study the influence of water content on the dielectric spectrum of oil paper insulated bushing, HN model was used to fit and analyze the dielectric spectrum parameters of oil paper insulated bushing with different water content. The experimental results show that HN model can be used to evaluate the wettability of oil paper insulation, but the evaluation range of wettability of oil paper bushing with complex insulation structure is not clear. The results show that the relaxation time constant decreases with the increase of water content, and has a linear relationship with the change of water content; the difference between high frequency dielectric constant and static dielectric constant increases with the increase of water content.
Procedures for Identifying Mutual Inductance of Three-Coil Structure for Wireless Power Transfer in Electric Vehicles
Authors: Liu Peizhou , Gao Tiande , Mao Zhaoyong , Liang Bo
Published: May 2021

Mutual inductance identification of the wireless power transfer (WPT) system is of great significance for improving the system performance. In this paper, a novel mutual inductance identification method for WPT in electric vehicles with three-coil structure is proposed based on the information measured from the primary and relay coils. The method deduces the influence of misalignment on mutual inductance of three-coil WPT system in electric vehicle application scenarios from a new perspective. The results show that the mutual inductance between primary and secondary coils, and the mutual inductance between relay and secondary coils can be estimated at one time by way of index according to the relationship between their ratio and themselves. Experimental results show the correctness of the proposed mutual inductance identification method.
Measurement method of adjacent harmonics or interharmonics based on Gaussian radial basis function frequency domain approximation
Authors: Guo Cheng , Duan Ruimin , Zeng Ye
Published: May 2021

Interpolated FFT method based on window function is a common method to measure harmonics or interharmonics in power systems. When the frequency resolution is insufficient or the main lobe of the window function is wide, the spectrum of adjacent harmonics or interharmonics may have aliasing of the main lobe, and it is difficult to accurately measure the parameters of harmonics or interharmonics. This paper proposes a modeling method for adjacent harmonics or adjacent interharmonics. The Fourier transform (FT) of the Gaussian function is still a Gaussian function. According to this feature, after adding a Gaussian window in the time domain and calculating the FFT spectrum, the real and imaginary parts of the aliased spectrum are decomposed into a series of linear superpositions of Gaussian radial basis functions (RBF). The center of the RBF is the frequency of the harmonic or interharmonic, and the amplitude and phase can also be calculated by the superposition coefficient of the RBF. The simulation verifies the effectiveness of the method.
Research on Power Demand Response of A Certain Area Power Grid for New Energy Consumption
Authors: Zhang Yi , Wu Yifeng , Zhang Feng , Cai Jianqiang , Li Yang , Tang Lv
Published: May 2021

With the rapid growth of new energy installation scale, new energy consumption is facing more and more pressure and challenge. Based on the characteristics of a certain provincial power grid, this paper starts from the point of view of promoting clean energy consumption, guiding electric heating load and other adjustable loads to optimize electricity consumption, relieving peak-shaving pressure of power grid, and strengthening the emergency regulation ability of the certain power grid, the power demand response of provincial power grid is designed and realized. This mode and methods have universal application value for provincial power grid with high proportion of new energy installation.
Operation control strategy of load aggregator based on new energy consumption in power grid
Authors: Jiang Mingjun , Wang Xiang , Dai Fengjiao , Xu Lanlan , Wen Xin , Shen Rendong
Published: May 2021

Managing the scattered small and medium-sized load by the existing ternary market model of regenerative electric heating is difficult. In this paper, the load aggregator is introduced on the basis of the traditional ternary market, transforming the existing ternary market model into the quaternary market transaction mode of new energy, power grid, load aggregator and regenerative electric heating users. The coupling relationship of four parties’ interests is studied for the win-win solution limited by the goal of obtaining the maximum income and assuming the minimum risk. A case of Northeast China is carried out and the results show that the maximum profit point is 0.5 yuan/kWh, 0.3 yuan/kWh and 0.1 yuan/kWh respectively.
Digital Twin of Beam Pumping Unit Control and Analysis
Authors: Ren Shuang Shuang , Shen Fei , Zhang Xiang Yang , Feng Chao Min , Luo Hong Wu
Published: May 2021

The software model of beam pumping unit was built through the physical simulation pumping unit lifting system in the Internet of Things laboratory, and the lifting model was updated after mutual verification to form the digital twin system of oil and gas production lifting. Based on the digital twin of beam pumping unit and the real-time data of oil and gas production, the whole process of oil and gas lifting process production is formed, and a flexible closed-loop control method based on the digital twin is obtained. The method is based on the detailed and in-depth analysis of the whole movement, which selecting the load as the monitoring physical quantity, and improving the system efficiency. The method is to change the maximum and minimum load, reduce the input power and improve the system efficiency under the condition of maintaining a certain output. By comparing and analyzing the indicator diagram of oil well production before and after the flexible control, the flexible control method based on digital twin reduces the loss of mechanical operation and saves the consumption of electric energy, so that the efficiency of the pumping unit’s lifting system reaches the maximum. At the same time, the control and analysis method based on digital twinning is a self-diagnosis, adjustment and control method of intelligent ecology, which is the inevitable trend of the development of intelligent oilfield.
Design and Test of Downhole Weight on Bit-Based Autodriller System for Horizontal Well
Authors: Wu Zebing , Zhang Wenchao , Zhou Kefei , Zhao Haichao , Huang Hai , Wang Jie
Published: May 2021

During horizontal well drilling, the pressure difference between the downhole weight on bit (DWOB) and the surface weight on bit (SWOB) will affect the service life of the drilling tool and the efficient production of oil and gas fields. An automatic drilling system device based on DWOB is designed. Choose the S7-200 smart PLC with good expansibility, combine the drilling rig automation principle, and use the Smart-700IE-V3 touch screen to design the human-computer interaction interface. Realize the real-time monitoring and prediction of DWOB. A large amount of test data shows that the new system not only has the advantages of the conventional automatic drilling system, but also can reduce or even eliminate the pressure difference between the surface and the bottom of the hole, achieve accurate control of the DWOB, improve bit performance, and reduce drilling costs.
Intelligent recognition of defects in vermicular graphite cast iron engine cylinder head by ultrasonic testing
Authors: Liu Qingyi , Jiang Ailong , Fang Duo , Zhang Chengqiang , Liu Zenghua , Liu Zehua , Guo Yanhong
Published: May 2021

To detect and intelligently identify the defects of the vermicular cast iron cylinder head, defective casting samples were made corresponding to each type of the actual defects. We setup the ultrasonic testing system to examine the defective samples. The detected defect signals were processed to obtain the characteristic spectrograms of the defects, which were further sorted and classified into a sample database. An algorithm based on a convolutional neural network was proposed to identify the defects intelligently. A convolutional neural network model was established. The network structure and parameters were optimized. It shows that a neural network with 3×3 convolution kernel dimension, 3 convolution layers, 20 convolution kernels in each layer and a learning rate of 0.0005 can effectively identify the spectrograms of the defects. The results show that the identification accuracy of the proposed algorithm is 97.14%. The model meets the practical requirements of cylinder head defect detection. The detection efficiency has improved significantly.
Fuzzy Control Strategy of Relief System for Extra-High Pressure Test Equipment
Authors: Xiao-hui Liang , Yu-de Fan
Published: May 2021

To realize accurate super-high hydraulic pressure curve control of relief system for isostatic pressure test equipment, a method of designing fuzzy control strategy, including theoretical analysis, modeling, designing fuzzy controller, optimizing fuzzy rules and simulation, was introduced. Precise mathematic model based on theoretical inferring and experimental computing was developed and used for studying control strategy and optimizing control rules. High-accurate controller based on fuzzy control theory was studied and fuzzy controller rules were optimized. A simulation platform composed of input variable, controller, mathematic model and output variable was obtained and successfully used for studying the control of relief process. Computer simulation and physical test experiments indict that the control precision of relief system reaches ±0.5Mpa during the pressure domain above 30MPa, the fuzzy controller strategy meets the high-accurate pressure control requirements of super-high pressure test equipment.
Research and Application of Knowledge Decision Method for Optimal and Fast Drilling in Emergency Rescue Wells
Authors: Yingzhuo Xu , Mingzhen Li , Yang Zhang , ZiXiang Yin
Published: May 2021

The efficiency of coal mine emergency rescue work is limited by the professionalism of decision-making, the efficiency of rescue team formation and the rate of resource mobilization. Knowledge sharing and inheritance have important reference meanings for improving the efficiency and success of rescue work. In order to improve the efficiency of rescue work, this article builds A knowledge base that meets the needs and research on key content[1]. This article first analyzes the knowledge engineering, knowledge representation and knowledge storage of emergency rescue well drilling; secondly, based on the analysis of the emergency rescue well work flow, it classifies the knowledge of fast drilling, and studies the knowledge expression based on ontology[2]. Construct the ontology model of knowledge and establish the knowledge base; then, in view of the shortcomings in the current knowledge retrieval, apply the full-text search to the retrieval of the fast drill-in knowledge, construct the retrieval model and design the index structure of the knowledge base, on this basis The ranking of knowledge retrieval is optimized. Finally, combine the retrieved knowledge and follow the emergency rescue process to form a set of decision-making plans. Through the application of the case study in this article, it is shown that the standardized management of the knowledge of excellent and fast drilling in emergency rescue wells is realized, the speed and quality of the acquisition of knowledge of excellent and fast drilling are improved, and the efficiency and professionalism of decision-making are improved.
Application of Downhole Camera Technology in Fault Diagnosis of Coalbed Methane Wells
Authors: Yin-hua Liu , Xue-jie Xing , Yu-bin Wang , Wan-yong Xu , Kai Liu , Yuan Lv
Published: May 2021

In the production process of coalbed methane well, due to casing damage, falling objects, sticking and other reasons, the continuous production is affected. In order to accurately identify the complex conditions of the gas well, the underground real-time camera technology can be used to diagnose the complex conditions of the underground, and provide a reliable operational basis for the next step of the overhaul construction measures. Through field application, the downhole camera technology can provide an accurate real-time picture of the gas wellbore, clearly capture the complex situation in the casing from the wellhead to the bottom of the well. It is of great guiding significance to analysis the causes of downhole faults and develop accurate repair measures.
An adaptive magnetization structure and method for low field NMR two-phase flow measurement
Authors: Li-pin LI , Rui-qiang Han , Yan-qun Huang , Huan Chen
Published: May 2021

In low field NMR multiphase flow measurement, the magnetization time and magnetization length are affected by the two-phase flow velocity and water fraction, so it is difficult to realize the complete magnetization of multiphase flow with fixed length magnet. In this paper, an adaptive magnetization structure for two-phase flow is proposed. The pre-magnetization model of the adaptive structure is established based on the magnetization theory of nuclear magnetic resonance. And parameters of the adaptive magnetization structure are determined by analyzing the influence of two-phase flow parameters such as velocity and water fraction on magnetic susceptibility. Finally, the simulation analysis shows that the adaptive magnetization structure can achieve complete magnetization effect for two-phase flow in the range of water fraction 0-36% and flow rate 0-4.66m/s, which provides the necessary conditions for the accurate measurement of NMR two-phase flow and provides a new idea for the design of NMR two-phase flow measurement sensor.
Seismic Signal Filtering based on Pseudo Wigner-Ville Distribution and Catte Model
Authors: Yanping Liu , Zheng Ma , Huiqin Jia , Jianshen Gao
Published: May 2021

In practice, there are various noises included in the collected seismic data. As a common background noise, random noise may interfere even annihilate valid signals. In view of this, it needs to adopt effective methods to eliminate random noise as much as possible. This paper proposes a filtering method that is based on pseudo Wigner-Ville distribution (PWVD) and Catte model. PWVD is a windowed form of Wigner-Ville distribution (WVD) which can make the nonlinear signal to be locally linearized in addition to weakening the influence of cross item. And the Catte model is a kind of anisotropic diffusion algorithm which can eliminate the noise while protecting the edge of image. The implementation of the proposed method is to do PWVD for the frequency modulation form of noise-containing signal and then to filter the PWVD via Catte model, at last to adopt peak search to obtain the estimation of the valid signal.
Research on a high-precision and high-resolution seismic wave signal acquisition system
Authors: Dan Wu , Hongtao Wu , Guowang Gao , Fei Wang
Published: May 2021

In oil and gas exploration, high-resolution seismic acquisition is an important research content of seismic exploration methods. In order to improve the accuracy and high resolution of the seismic wave acquisition system, a seismic wave signal acquisition system based on the 32-bit high-resolution analog-to-digital converter ADS1282 is designed in cooperation with a high-anti-interference and high-resolution piezoelectric geophone, Improve the resolution of seismic wave signal acquisition from the two aspects of seismic wave pickup and analog-to-digital conversion. The system chooses the high-performance, ultra-low power consumption Microcontroller MSP430F149 as the control core of the acquisition system, which effectively reduces system power consumption. System debugging results show that the collected data of ADS1282 is stable to 24 bits, and the consistency is good.
Image Mosaic in Visual Detection of Wellbore
Authors: Xifeng YI , Yuguo Liu , Feng Zhang , Hengchao Gao , Yugang Tian , Jianfei Wei , Zhengguo Yan , Yinchuan WU
Published: May 2021

Based on the research on the visual detection system, this paper analyzes the characteristics of wellbore video (image), proposes the key techniques of image processing, and designs the methods of image mosaic. The experiment results show that when the image correction, the perspective transform, the image registration, and image fusion are implemented, a panoramic image of wellbore can be obtained. This study provides a new perspective for the visual detection and the technology reserves for further quantitative evaluation of visual detection.
Performance analysis of a wavelet packet transform applied to concrete ultrasonic detection signals
Authors: Hu Tianyu , Zhao Jinhui , Yan Shubin , Zhang Wei
Published: May 2021

In the ultrasonic detection technology of concrete health conditions, it is difficult to identify damage features due to the complex wave synthesis of detection signals. We propose a method of applying wavelet packet transform (WPT) to decompose and reconstruct the ultrasonic detection signal from a C30 class concrete, thereby reducing noise and redundant information. We can obtain the main frequency node coefficients by wavelet packet decomposition, and reconstruct the denoised signal by the node coefficients. For analyzing the performance of this method, the extracted indices of signal-to-noise ratio, root mean square error, Pearson correlation coefficient, and smoothness are utilized and evaluated respectively. Ten simulated signals and ten actual detection signals are employed for evaluating the method. Simultaneously, the comparison with the calculation results of the empirical mode decomposition (EMD) method is created. It is shown from the experimental results that WPT has better denoising performance on the signals. Finally, an experiment of the processed signal quality assessment is constructed. The stochastic configuration network (SCN) is employed as the evaluation model for exploring the influence of the proposed denoising method on identification accuracy. The result shows that the proposed method of reconstructing the main frequency node coefficients by WPT retains useful information more effectively and improves the identification accuracy of the recognition model.
Analysis on fracturing effect of polymer flooding oil layer II1-9 in North Region I
Authors: Junhua Kang
Published: May 2021

Fracturing, as an important means to tap potential remaining oil and alleviate three contradictions, has a great contribution to the completion of production. Since the implementation of measures to increase oil and create efficiency project in 2017, the fracturing effect has been greatly improved. This paper analyzes the development characteristics and production status of the reservoir, and expounds the necessity of fracturing in this block. Taking a single well as an example, this paper analyzes two types of Wells with the purpose of low-efficiency well treatment and thick-layer well fracturing effect from the aspects of well selection conditions, development status, measure technology, measure effect and post-pressure protection, etc. providing reference for the implementation of the whole process fracturing measures in the block of the second-class reservoir.
Feature Extraction of Down-hole Drilling-plug Impact Signal Based on Empirical Mode Decomposition
Authors: Xu Feiyan , Yang Quanzhi , Wu Bin , Zhang Xiaobin , Yu Xiaolong , Wan Shoubo
Published: May 2021

For analyzing the non-stationary drilling-plug impact signal under the complicated drilling environment, use of conventional discrete Fourier Transform (DFT) has been known to be less efficient. To extract useful information contained in the drilling-plug impact signal, a new extraction method based on empirical mode decomposition (EMD) is presented. In the signal processing, EMD is used to decompose the original drilling-plug impact signal into the intrinsic mode functions (IMFs). By analyzing kurtosis and energy spectrum of the IMFs, the first three IMFs are found that contain the characteristic of the drilling-plug, and the specific frequency band of the drilling-plug impact signal is determined after power spectrum analyzing. The reconstruction drilling-plug impact signal after band-pass filter can clearly show the detailed process of the drilling-plug such as drilling the rubber plug, drilling the float collars and drilling the formation.
Ultrasonic Guided Wave Damage Detection Method for Stiffened Plates Based on Deep Learning
Authors: Shen Qing , Yue Shengyao , Lu Wei , Xu Guidong , Xu Chenguang , Xu BaiQiang
Published: May 2021

In order to solve the problem of debonding damage detection commonly exists in stiffened plates, we propose an ultrasonic guided wave damage detection method based on deep learning and conduct a numerical study of the method. The guided wave signal get from a Finite-Element-Model (FEM) is pre-processed through wavelet transform to obtain the wavelet coefficient matrix (WCM), which is input into Convolutional Neural Network (CNN) in the form of gray image to obtain the neural weights. The detection accuracy of debonding damage in the stiffened plate has reached nearly 99%.
Design of arm layered oil recovery data monitoring system
Authors: Huiqin Jia , Cheng Cheng , Ruirong Dang , Gan Li
Published: May 2021

Aiming at the different characteristics of different reservoirs between oil wells, this paper studied and designed a layered underground oil recovery data acquisition system based on ARM Cortex-A7 architecture. This system mainly consists of three parts, namely sensor, measurement circuit and data acquisition and processing. I.mx6ull is selected as the main control chip, and a data acquisition platform is built with the peripheral device AD8229 instrument amplifier. The SPI protocol and state machine are used to communicate with the downhole multi-reservoir data, and ESP8266 module is used to transmit the downhole multi-parameter data to the Alibaba Cloud server. Through the software and hardware experiment system test, it shows that the designed system has the characteristics of good real-time performance, high precision and low cost.
Simulation and Implementation of NPC three-level inverter SVPWM algorithm
Authors: Zhang Tao , Lu Xiuhe , Shi Yuanlin
Published: May 2021

Taking diode clamp type three-level inverter as the research object, the principle of SVPWM algorithm is introduced, and the relationship between SVPWM algorithm and two-level algorithm is described. On this basis, the simulation principle of two-level SVPWM algorithm is used for reference, and the three-level space vector algorithm is simulated according to MATLAB/Simulink simulation environment. Finally, the simulation results under three-level and two-level modulation show that the three-level inverter SVPWM algorithm can reduce harmonics, and the simulation experiment verifies the correctness and feasibility of the control method.
Research of Incremental Learning Algorithm for SVM Based on Class Center Diameter
Authors: Li Jinfeng , Xie Wenhao
Published: May 2021

In the learning process based on ISVM, how to effectively retain the history information and selectively discard some new training data, so as to maintain the classification accuracy and save the storage space after adding new samples every time, which is the key of the current ISVM classification algorithm. This thesis proposes a new incremental learning algorithm, that is, SVM incremental learning algorithm based on cluster diameter (CD-ISVM). This algorithm firstly calculates the two centers of the positive and negative samples, and then to build the boundary vector set by the coordinates of the two class centers. Moreover, KKT conditions are combined to filter incremental data and boundary vector set, and feedback information is provided to adjust the position of the boundary vector set. Then, the union of SV set and boundary vector set is taken as the increment set. After several increments, a classifier with strong generalization is finally trained.
A New Method of LCL Filter Parameter Design Based on Fish Swarm Algorithm
Authors: Liu Sining , Wang Wei , Zheng Ruize
Published: May 2021

Aiming at the problem that LCL filter is better than L, LC filter in filtering performance. However, the selection of parameters is more complicated, and it is prone to resonant spikes in the filtering process, this study introduces passive damping to measure its resonant spikes suppression, and combined with the attenuation of the grid-connected harmonic current of the LCL filter to measure its excellent filtering performance. Based on this, the objective function model is established, the fish swarm algorithm is adopted to optimize its parameters, and the grid-connected simulation model is found in MATLAB/Simulink. Its filtering effect is compared with the traditional method. The simulation proves that the filter after parameter optimization can effectively suppress and filter the harmonic components of the inverter output voltage compared with the conventional filtering method, and provide positive theoretical guidance for the stable grid connection of new energy power generation.
A Prediction Model for Water Absorption Profile Based on IDW-DTW-RNN Method
Authors: Zhao Xu , Fu Ju Yao , Xiong Hong Li , Yu Gao Ming
Published: May 2021

At present, many low-permeability oil fields are entering the later stages of development, and there will be problems of difficulty in water injection and poor water injection effects. Obtaining water absorption profiles and their changes can more effectively help formulate layered water injection strategies. Generally, the isotope water absorption profile method is often used to obtain the water absorption profile. This method is accurate, but the test cost is higher and the actual oil field measurement data is less. Based on the measured water absorption profile data, this paper selects 8 factors including effective thickness of oil layer, effective permeability, measure coefficient, crude oil viscosity, crude oil volume coefficient, injection-production pressure difference, well spacing, and connection coefficient between oil and water wells as the main influencing factors of the profile prediction model. Taking water injection wells data with 8 factors as input, a water injection profile prediction neural network model based on inverse distance weighting method and dynamic time warping, namely called IDW-DTW-RNN, is trained in this study. This model is applied in oil field, and the accuracy is obviously improved compared with the conventional method, which is in line with the actual development situation. It provides a scientific basis for the adjustment and optimization of the later injection-production structure of the oilfield.
Research Status and Development Trend of Water Cut Detection Methods for Crude Oil
Authors: Guowang Gao , Dasen Hou , Hua Le , Wang Fei , Li Yuanbo
Published: May 2021

Water cut detection of crude oil plays a very important role in the petroleum and petrochemical industry. At present, the existing crude oil water cut detection methods include capacitance method, conductance method, radio frequency method, Ray method, spectrum method. Firstly, the measuring principle, application conditions, advantages and disadvantages of the existing methods are summarized, and the factors affecting the measuring accuracy of the existing methods are analyzed. Afterwards, the latest development of water cut measurement technology of crude oil is mentioned, such as multi-sensor information fusion technology, tomography technology, neural network technology. With the emergence of new technology and new method, the development trend of crude oil water cut measurement technology is towards full range, high precision, intelligence, multi-parameter fusion, safety, energy saving, environmental protection and so on.
Water Body Extraction from High-resolution Remote Sensing images Based on Scaling EfficientNets
Authors: Lu Li , Qi Wen , Bing Wang , Shichao Fan , Li Lingling , Qingjie Liu
Published: May 2021

Effectively and accurately extracting water bodies from high-resolution remote sensing images is an important yet extremely challenging task due to ambiguities raised by spectral and texture similarities between water bodies and distractors such as shadows buildings, mountains and vegetations. Recent developed deep learning techniques have provided researchers powerful tools to defeat traditional hand-engineered features by learning powerful hierarchical representations, however, with a cost of very high model complexity and computational resource requirement. To conquer this issue, in this paper, we propose to build a deep learning model for water extraction based on the EfficientNet-B5. We evaluate possible variations of such design and compare them with several widely used approaches on GF-2 and Sentinel-2 satellites. Experimental results demonstrate that our model obtains much better performance than SVM and U-Net, which clearly shows the effectiveness and robustness. We hope this work will facilitate further research in this field and inspire researchers in the community to develop better models.