bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Analysis of Distributed Compressed Air Energy Storage under Different Air Storage Chamber Models
Authors: Wang Kangxiang , Zhu Chuang , Du Xili , Di Yanqiang , Chen Laijun
Published: May 2023

To address the challenges brought by geographical, climate, and user dispersion in regional microgrids, villages in northwest China for example, a distributed compressed air energy storage combined heat and power model considering the thermodynamic characteristics of air storage devices is proposed. Firstly, the architecture of distributed compressed air energy storage system based on regional microgrids is constructed. Then, considering the thermodynamic characteristics of the air storage device under constant volume and insulation, a cogeneration model of distributed compressed air energy storage is established. The model includes compression subsystem, air/heat storage subsystem, and expansion subsystem. Finally, the results of combined heat and power supply of distributed compressed air energy storage system are discussed by case study simulation in different air storage chamber models. The results show that constant volume insulation as the air storage device is the best choice, which improve the system efficiency by up to 25.6%. The research results provide a theoretical basis and decision-making reference for the application of distributed compressed air energy storage system in complex environment.
Research and application of load forecasting method for park integrated energy system based on XGBoost algorithm
Authors: Chi Kun , Li Yuan , Gao Yue , Zhao Yuyang
Published: May 2023

Load forecasting is the basis of energy management and optimal dispatching of the park-integrated energy system, and its forecasting accuracy directly affects the overall operation performance of the system. Therefore, this paper proposes a load forecasting method for the park-integrated energy system based on the XGBoost algorithm. This paper first establishes the simulation analysis model of photovoltaic power generation and electric vehicle charging and discharging in the park and then carries out the supply and demand forecast and load characteristic modeling of the park’s energy system. Finally, this paper constructs the power prediction optimization control flow based on the XGBoost prediction model and uses the mean absolute percentage error (MAPE) and root mean square error (RMSE) as two evaluation indicators. The validity of the proposed method is verified by the data of the actual micro energy system in the park.
A Combing Data-Driven and Model-Driven Methods for Renewable Energy Acceptance Capacity Assessment in Distribution Networks
Authors: Xin Haokuo , Jiang Minglei , Lu Yu , Zhang Ying , Yu Wenfang , Jin Xinlong
Published: May 2023

To accurately improve the balanced new energy distribution network capacity assessment, this paper proposes a combined data-driven and model-driven renewable energy capacity assessment method for distribution networks. Firstly, the distribution generations (DG) output data are pre-processed to construct a scenario training sample set and extract seven types of DG daily output characteristics indicators. Secondly, a scenario generation model based on a conditional generation adversarial network is proposed to realize the coupling of scenario reduction and scenario generation based on K-means++ through daily output characteristics indicators. Finally, the optimization model based on hybrid positive linear programming is proposed for distributed power supply acceptance capacity evaluation of the distribution network with the objective of maximum DG access capacity and full consideration of voltage deviation, branch current, tidal current return, and other operational constraints. It is validated by IEEE 33-bus simulation. The simulation analysis shows that the proposed method can effectively quantify the DG capacity uncertainty compared with the traditional method, and the proposed method has higher computational accuracy and efficiency than the traditional method.
Optimal Configuration Model of Energy Storage System and Renewable Energy Based on a high proportion of Photovoltaic Power
Authors: Chen Jie , Li Xuxia , Jing Yongming , Zheng Xiaoming , Deng Jiaojiao , Wang Yao , Wang Kaikai , Hu Yingying
Published: May 2023

With the proposal of the dual-carbon target, renewable energy generation cannot meet the requirements of flexible grid dispatching as traditional power generation energy. Therefore, the proposal of storage energy has become an important development direction. This paper established an optimal configuration model which is applicable to high-proportion photovoltaic power. Then, the rationality of the scheme is evaluated through complementary effects. In the end, the feasibility of the model proposed in this paper is proved by practical cases. The results show that the model can alleviate the peak shaving task undertaken by energy storage, avoid excessive allocation, and reflect the difference in energy storage allocation in various cities.
Research on Partial Discharge Detection of Switchgear Based on Ultrasonic Signal Characteristic
Authors: Zhu Xiaofeng , Lu Lizhong , Jiang Yanjin , Liu Yongshuai
Published: May 2023

With the rapid development of power systems, the switchgear, which is widely used, plays an increasingly important role. Partial discharge is one of the main causes of insulation failure of the switchgear, which is a serious threat to personal and equipment safety. In this paper, the partial discharge of the switchgear is detected based on the ultrasonic method. According to the characteristics of ultrasonic waves generated by partial discharge, a partial discharge detection method for the switchgear based on the characteristics of ultrasonic wave signal is designed. The wavelet threshold denoising algorithm is used to denoise the ultrasonic signal and draw the partial discharge phase distribution map by using the characteristics of low amplitude and wide frequency distribution of the interference signal. Finally, the improved support vector machine algorithm is used to identify and diagnose four types of discharge based on 280 groups of experimental data. By adjusting the kernel function and optimizing the support vector machine algorithm, the final recognition accuracy is more than 90%.
Coordinated planning of source load storage flexible resources for photovoltaic access to power system
Authors: Hu Jiankun , Xie Wenyan , Chen Zhijian
Published: May 2023

A coordinated planning method of source load storage flexible resources for photovoltaic access to the power system is proposed to improve the operation stability and economy of the power system. The basic operation characteristics of PV-connected power systems are analyzed from the perspectives of power flow, voltage, and frequency. According to the analysis results, a resource coordination planning model is built to determine the cost, the lack of flexibility to adjust the cost, and other objective functions. On this basis, the corresponding constraints are proposed and solved by the ant colony algorithm to achieve flexible resource coordination planning. The experimental results show that compared with the existing methods, the proposed method has a higher confidence level of flexibility requirements, indicating that it has a higher energy storage and regulation capability.
An EHV Transformer Fault Diagnosis Method Based on Acoustic Perception and Sparse Autoencoder-BNCNN
Authors: Xu Mingkai , Lv Xuebin , Li Cong , Zhang Faye , Liu Chunming , Liu Minghui , Zhang Yilan , Jiang Mingshun
Published: May 2023

The EHV transformer is one of the core transmission equipment of China’s EHV/UHV transmission system, and its reliability directly affects the operational stability of the power grid. In the long-term operation process, affected by sudden short-circuit, resonance, and aging, it will produce faults such as loose winding, loose iron core, inverted discharge, and shim block shedding. Most of the methods for transformer fault diagnosis need off-line monitoring and cause some damage to transformer equipment. At present, the use of transformer acoustic signal for diagnosis and identification is in the initial stage, and there is still room for improvement in the accuracy of fault diagnosis, and how to classify the unbalanced data samples also deserves attention. Therefore, an EHV transformer fault diagnosis method based on acoustic perception and sparse autoencoder-BNCNN is proposed in this paper. Firstly, the sparse autoencoder is trained to ensure the processing ability of the network on imbalanced data. Then, the high-step CNN network is optimized using the BN layer, the data is fed into the improved CNN network for feature extraction, and the classifier outputs the fault diagnosis results. Finally, the transformer acoustic data are processed, and the dataset is formed to evaluate the performance of the proposed method. The experimental results show that the proposed method not only improves the accuracy substantially compared with other methods but also has the ability to handle imbalanced data.
Multi-objective Collaborative Optimal Dispatching Method for Active Distribution Network Based on Improved Genetic Algorithm
Authors: Lin Zhengchong , Tian Qidong , Mei Peng , Lin Zhixian , Lin Zhangsheng , Zhang Chen
Published: May 2023

New energy connected to the grid reduces the environmental pollution caused by the combustion of traditional fuels, so it is of great practical significance to vigorously develop renewable energy for the development of a distribution network. The system composition and operation structure of the active distribution network and the traditional distribution network are roughly the same. The main difference lies in the control mode of the two. By changing different control modes to adjust the operation mode, the main task of the active distribution network optimal dispatch is to improve its economy and power quality, but it is easy to fall into local optimum and slow convergence. In this paper, the traditional genetic algorithm is improved. The multi-objective co-generation system is mathematically modeled to construct the optimization objectives. The economic benefit of the co-generation system is maximized. The fluctuation of the output power following the load is minimized, and the requirement of carbon emission minimization is met. Through optimal control technology, the reasonable action of a variety of control equipment can be achieved. The voltage can be prevented from exceeding the limit. The multi-objective coordinated regulation ability can be improved, which is significant in practical engineering and intelligent control.
Improved double-ended traveling wave ranging technology for DC distribution cable lines
Authors: Liu Zhong , Zhang Kaixin , Zhang Junyan , Shi Shenxing , Liu Hengmen , Dong Xinzhou
Published: May 2023

This paper analyses the main factors affecting the accuracy of double-end traveling wave ranging for high precision fault ranging on cable lines in DC distribution networks, and points out that the double-end traveling wave method for DC segmented cables based on uniform wave velocity is the main source of fault ranging errors. Then, an improved double-end traveling wave ranging method based on the refined wave velocity of segmented cables is proposed. Based on the linear relationship between the fault traveling wave time difference and the fault location at both ends of the cable, the measured cable segmental wave velocity is used to form a ranging function to derive accurate ranging results. PSCAD simulation experiments demonstrate that the proposed method significantly improves the segmental cable fault ranging accuracy.
Power flow analysis of 110kV power supply system based on PowerWorld
Authors: Wen Huixian
Published: May 2023

With the growing global interest in various economic and environmental benefits of the power system, it is essential to ensure the safe and stable operation of the power grid. The optimal power flow calculation method is studied using the PowerWorld and Newton-Ralfsnn methods. The results calculated by the Simulator LP OPF function are compared with the manual calculation of the 110 kV power supply system grid. After optimization, the total cost is saved by 623.05 ¥/h. The simulation results can directly and vividly reflect the power distribution and optimize the power supply and distribution power flow.
The research on data acquisition and processing method of photovoltaic special metering protection unit based on LMS adaptive filtering
Authors: Fu Zhaohui , Chen Zhiru , Kong Hongwei , Jiang Guixiang
Published: May 2023

In order to solve the problem of synchronous acquisition of multi-parameter data of photovoltaic special metering protection unit and reduce the noise pollution of sensor data, this paper designs a multi-parameter data acquisition system of photovoltaic special metering protection unit; The system uses RN7326 and SWM32F103R chips as the main and auxiliary microprocessors, and designs a scheme of multi-sensor signal filtering and interface resource acquisition; The standardized data communication protocol is studied and designed to realize the synchronous data acquisition of multiple sensors; Finally, the LMS (Least mean square) based on adaptive filtering method is used to reduce the noise of multi-parameter data. In this paper, the temperature sensor pt100 is taken as an example to conduct temperature acquisition and filtering processing experiments. After data filtering, the noise above 1Hz is basically eliminated, and the noise pollution is effectively reduced when the noise amplitude is less than 1Hz, and the accuracy of sensor data is improved.
Research on the seepage mechanism and influencing law of shale oil fracturing
Authors: Zhang Yanyu , Wang Yue , Sun Xiaofei , Xu Long , Sun Yuxin , Xia Anlong , Dong Mingzhe
Published: May 2023

In order to clarify the characteristics of oil and water seepage during shale oil fracture, the tight reservoir in Jimsar Basin, Xinjiang Province was an example to get the characteristics of two-phase seepage between fracturing fluid and shale oil during fracture through the core experiment during injection. Effects of initial water saturation, viscosity ratio of oil to water, injection pressure, core permeability about imbibition displacement efficiency of fracturing fluid were systematically studied by using an improved one-dimensional core displacement device from Xinjiang tight sandstone artificial core under indoor conditions. The research results show that under constant pressure of 1 MPa, initial water saturation of the core is 43%, permeability is 0.12 md, and oil-water viscosity ratio between shale oil and fracturing fluid is 3:1, drive efficiency about fracturing fluid was about 23.5%. At the same time, results indicated at certain injection conditions, when initial water saturation increases, the permeability gradually decreases, and the viscosity ratio of oil to water gradually increases, the lower drive efficiency of fracturing fluid was, the worse its effect is. This conclusion could be used in the process of shale oil tight reservoirs.
Short-term Electricity Load Forecasting Based on TPE-optimized CNN-BIGRU-Attention
Authors: Wang Wenhui , Xi Caiping
Published: May 2023

To fully exploit the time series characteristics of the electricity load data and further improve the prediction accuracy for the intelligent dispatch of the power grid, this paper proposes a combined model of short-term electricity load forecasting based on the Bayesian optimization algorithm (TPE) optimized convolutional neural network (CNN) — bi-directional gated recurrent network (BiGRU) — Attention mechanism (Attention). First, the data are pre-processed by normalization and removal of missing values. Then, a CNN-BiGRU-Attention prediction model is built and the TPE algorithm is used to determine the hyper-parameters. Finally, the trained model is used to complete the load prediction. This paper takes a region of China’s electricity load data as an example for seasonal forecasting, and experiments show that the model in this paper has stronger adaptability and higher forecasting accuracy compared with CNN, GRU, CNN-GRU, and CNN-BiGRU networks.
A Cross-Domain Authentication and Authorization Model for New Power System Based on Trust Management
Authors: Li Wei , Xu Huiyan , Zhang Jiyu , Zhou Yandong , Wu Jiao , Li Shu
Published: May 2023

The access of new power service terminals brings about a new demand for cross-domain and cross-system security access. Therefore, this paper proposes a cross-domain authentication and authorization model for a new power system based on trust management, which is realized through the cooperation of certificate authority, authentication module, authorization module, and trust management module. Firstly, the model proposed in this paper includes a cross-domain authentication method, which realizes authentication between domains by issuing and verifying tokens for terminals with sufficient trust. Secondly, the model includes an authorization method based on attribute and trust value, which realizes the authorization of the terminal through attribute policy and trust evaluation. Finally, a trust value calculation method for terminal cross-domain access is included in the model. In this paper, the proposed model and method are simulated to demonstrate the correctness and effectiveness of the model. The experimental results show that the model has the advantages of universality, efficiency, and ease of management, and the terminal can access resources safely and efficiently across domains.
Cooperative Fault Ride Through Strategy for Paralleled Grid-Tied Converters
Authors: Ma Chunyan , Duan Qing , Sha Guanglin , Wang Haoqing
Published: May 2023

Parallel systems are the trend of the grid-tied converters, which can improve the transmission power. Under fault conditions, the operation of the converter needs to be switched safely to ensure no disconnection. The cooperation between multiple converters can better cope with fault conditions and support the grid voltage. This paper proposes a coordinated fault ride through strategy. This strategy can ensure that the converters transfer the required reactive power into the grid according to their ability, and calculates the current feasible region. The residual capacity is used to transmit photovoltaic power within the current feasible region. Thus, the converters can operate within the safety region and help to restore the grid voltage. Simulation results verify the correctness of the proposed strategy.
Current Situation Analysis for the Integration and Detection Methods of the Primary and Secondary Switch
Authors: Jin Cuicui , Yue Yang , Meng Qinglin , Zhang Chunhui , Yao Ying , Zu Guoqiang
Published: May 2023

The distribution equipment is core to intelligent distribution and directly determines the reliable operation of distribution networks. The primary and secondary integrated switchgear is an integration of the traditional primary switch, sensor, and secondary controlling terminal. It is influenced by temperature, pressure, electromagnetic interference, etc. To guarantee the quality of the primary and secondary integrated switchgear which is accessed to the power grid, the inspection outline of the primary and secondary integrated switchgear in the State Power Grid includes the structure and configuration, appearance inspection, insulation resistance test, power frequency voltage withstand test, and lightning impulse test.
Analytical Method for Nonlinear Vibration of PLL-type Grid-connected Converter
Authors: Xiong Jiawang , Ye Hua , Pei Wei , Kong Li
Published: May 2023

In recent years, large-scale renewable energy equipment has promoted the development of grid-connected converters. Among the existing grid-connected converters, PLL-type grid-connected converters are in an unshakable position in the business. As a key device, PLL also plays an irreplaceable role. However, due to the nonlinear characteristics of PLL itself, traditional linear methods cannot be used for more in-depth research, and the existing methods do not systematically obtain the approximate analytical solution of this kind of nonlinear model. Therefore, based on the PLL-type grid-connected converter model, this paper introduces the nonlinear vibration theory to obtain the approximate analytical solution of the model. Specifically, the dynamic model of a PLL-type grid-connected converter system is obtained through the inherent characteristics of the components. Then the normal perturbation and the averaging method are introduced to derive the approximate analytical solution of the model. Finally, the correctness of approximate analytical solutions is verified through experiments, and the application scenarios of the method are summarized.
Design of Power Grid Equipment Life Cycle Management System Based on RFID
Authors: Lei Chuanli , He Yuqing , Chen Liang
Published: May 2023

The conventional life cycle management system of power grid equipment has the disadvantage of time-consuming information processing when it manages a large amount of information. Therefore, the design of the power grid equipment life cycle management system based on RFID is proposed. Referring to the overall architecture of the system, the hardware equipment required by the system is defined, and the electronic tag card and information reader are designed to complete the hardware design of the system with the radio frequency identification technology RFID as the control core of the system. On the basis of the hardware, according to the basic functions of the system, the software part is designed. The design of the power grid equipment life cycle management system is realized combined with the system hardware. The application performance of the designed system is verified by the system test, and the results verify that the information processing time of the designed system in equipment management is shorter, which can effectively improve management efficiency.
Stability Constrained Two-Stage Robust Optimization Model for Microgrid Economic Dispatching
Authors: Chen Wei , Han Yuqi , Liu Fang
Published: May 2023

With the development of high penetration renewable energy, the power system has faced a big challenge of low inertia and weak frequency support. This paper proposed a two-stage robust mathematic optimization model with three layers to cope with the uncertainty in microgrids considering inertia and frequency constraints. The controllable generators in the microgrid were modeled, including gas turbine, energy storage, and demand response. The uncontrollable photovoltaic and wind turbine are described with an uncertainty set that can be observed by weather forecasting errors. Second, the economic dispatching model considering inertia demand constraint can reasonably arrange the startup and shutdown plan of units, decrease the frequency change rate after disturbance, and improve the inertial response ability of the system. Finally, the case study results show the effectiveness of the proposed model.
Optimization Design of Voltage Stabilization Based on Three-Phase Rectification, APF and PWM Technology and Its Application in Grid-connected Transmission
Authors: Lin Zheping
Published: May 2023

Aiming at the problems of voltage fluctuation and harmonics in photovoltaic grid connection, the improvement of a three-phase rectifier circuit is proposed, and the results are verified by MATLAB simulation. At the same time, this paper also puts forward the application of a three-phase four-wire three-level parallel APF structure and Three-term rectifier PWM rectification technology. By compensating harmonic current generated by APF and controlling the switching state of the inverter by PWM, the bidirectional flow of electric energy can be realized, and the harm of harmonic and voltage fluctuation of photovoltaic grid connection can be solved.
A Calculation Method of the Hosting Capacity of Distribution Network based on Optimal Power Flow
Authors: Zhao Zhiyu , Zhao Tianqi , Ma Zhihao , Wang Zesen , Xie Huan , Li Xuan
Published: May 2023

With increasing and massive photovoltaic (PV) connected to the distribution network(DN), there will be two-way power flow in traditional DN. As one indicator to measure the maximum amount of active power that certain bus of distribution network (DN) can be injected, the hosting capacity of DN is to be a research hotspot. This calculation method of hosting capacity of DN is presented based on optimal power flow (OPF)model and commercial solver. Based on the branch power flow equation with relaxation method, the maximum active power of renewable energy source (RES) that can be injected to DN is calculated precisely. An improved IEEE 33 buses case validates the correctness of the proposed calculation model.
Failure analysis of the sewage pipeline on a shale gas platform
Authors: Chen Yanjun , Tang Li , Wang Qiliang
Published: May 2023

The wall thickness of the sewage pipeline on a shale gas platform is seriously reduced. In order to explore the specific reasons for the pipeline failure, this paper carried out analysis by means of macroscopic inspection, mechanical property test, chemical composition analysis of base metal and corrosion product analysis. The analysis results show that the site of this pipeline corroded most seriously is at 5 o ′clock and 12 o ′clock near the outlet, and the corrosion of liquid accumulation containing CO2 is the main reason for the serious failure of the inner wall of this pipeline. This paper explores the specific reasons for the failure of the sewage pipeline on a shale gas platform, and provides a reference for the corrosion prevention of the sewage pipeline.
Granularity reconstruction and characterization of silicon carbide micronized powders
Authors: Wang Jialin , Liu Shikai , Song Zhijian , Han Bibo , Wu Haocheng
Published: May 2023

Water glass and silica-alumina sol were used as adhesives, uniformly mixed with silicon carbide powder. The effects of binder, binder concentration, sintering temperature, and sintering process on the granularity reconstruction of SiC powders were studied in detail. The results show that when water glass is used as the binding agent, vacuum sintering can effectively inhibit the oxidation of silicon carbide, and suitable granulation and sintering samples are obtained at a concentration of 5%. When silica-aluminum sol is used as the binding agent, it is discovered that the increase in engagement can effectively increase the particle size, and the best effect is achieved at a concentration of 10%. Both systems of binding agents can successfully bind silicon carbide micronized powder, enlarge silicon carbide particles, and accomplish the goal of Granularity reconstruction.
Research on warping optimization of automobile mesh based on artificial intelligence algorithm
Authors: Shan Zhi
Published: May 2023

Automobile mesh is a typical large plastic part prone to warping deformation in the manufacturing process, which seriously affects the quality of products. The traditional method is to find the optimal combination parameters to reduce warping deformation in the forming process through repeated trial or mold flow analysis with high cost. In this study, An optimization method based on an artificial intelligence algorithm is proposed to optimize the warping deformation of the automobile mesh. In the optimization method, artificial intelligence regression algorithm-support vector machine regression was used to establish the nonlinear function relationship (prediction function) between the molding process parameters and the warpage of automobile mesh, and the performance of the prediction function was optimized by a genetic algorithm. The optimized prediction function was taken as the fitness function, the warping value was regarded as the fitness value, and genetic algorithm is used again to obtain a set of optimal process parameters and minimum warpage values. Finally, the reliability of the optimization method is verified by the modal flow analysis software.
Effect of Hydrophobic Silica Particles on Mechanical Properties of Bromobutyl Rubber (BIIR)
Authors: Gui Chen , Hou Jianan , Wang Kai , Gao Qun , Zheng Kang-Sheng
Published: May 2023

Silica is one of the most important reinforcing fillers in the rubber industry. As an excellent reinforcing agent, it can endow rubber with higher tensile strength, elongation at break, elasticity, heat resistance, tear strength, etc., and is widely used in rubber products. BIIR has good air tightness, fatigue resistance, aging resistance, chemical resistance, and good processing performance, so it is widely used in tires and other industries. In this paper, three hydrophobic nano-powder materials, silica airgel, hydrophobic fumed silica and hydrophobic precipitated silica, were added to BIIR during rubber mixing and vulcanization. The effects of three nano-powder materials on the physical and mechanical properties of BIIR were compared. The results show that all three hydrophobic silica nano-powder materials can effectively improve the mechanical properties of BIIR, among which silica airgel has the most significant enhancement effect on the mechanical properties of BIIR. The tensile strength of 40% airgel-reinforced vulcanized rubber can be increased from 2.42MPa to 5.84MPa. The 100% constant tensile stress can be increased from 0.34MPa to 1.04MPa, while the tear strength is high (19.07N/mm), the hardness is extremely high (89HA), and the thermal conductivity is as low as 0.13439 (W/m·K).
Design of High Sensitivity Cellulose Filter Paper-based SERS Flexible Substrate for Testing Harmful Rust of Bronze Ware
Authors: Zhang Yahui , Li Pengyang , Zheng Xiongbiao , Zhou Sheng , Huang Xia , Chen Jiachang
Published: May 2023

Surface-enhanced Raman scattering (SERS), a simple, highly sensitive, and fast analytical method can be used to detect corrosion components on the surface of bronze ware, a difficult problem. The silver mirror reaction is suggested for depositing precious metal nanoparticles on cellulose filter paper in order to create a quick, easy, and low-cost approach for creating SERS substrates. After an 8-minute deposition time, optical microscopy and scanning electron microscopy (SEM) revealed a uniform dispersion of precious metals on cellulose filter paper. To examine the SERS characteristics of the substrate, copper chloride oxide, the main ingredient in the damaging rust of trace bronze ware, was used as the probe molecule. The findings show that cellulose filter paper with a uniform distribution of precious metals achieves the best SERS performance. The flexible substrate enables effective trace analysis of damaging rust on bronze surfaces.
Comparative Analysis on Microstructure and Properties of Welding Joints of Q350EW and Q355GNH Weathering Structural Steel
Authors: Guo Shibin , Liu Zijing , Su Yunhai
Published: May 2023

High weather-resistant steel has excellent weather resistance, mechanical properties, weather resistance, superior economy, and other characteristics and is widely used in high-speed rail trains. Due to the shortage of corrosion-resistant elements such as Ni and Cr in China, weathering steel with Cu+high P as the main component is widely used. This paper aims to study the mechanical properties of the newly developed material Q350EW weathering steel welded joint and compare it with the traditional Q355GNH material. The microstructure of the welded joint of Q350EW and Q355GNH was observed by optical microscope (OM) and field emission scanning electron microscope (SEM). The tensile properties, hardness, impact properties at different temperatures, and fatigue strength of the two sheets of steel were tested. The results show that the grains in the weld zone of the two steel sheets are fine and equal. The tensile properties of the two sheets of steel meet the applicable standards. The hardness distribution of the Q355GNH welded joint is more uniform than that of Q350EW. The impact toughness of the Q355EW welded joint at -40 °C does not meet the standard requirements. The fatigue limit of the Q355EW welded joint is slightly lower than that of the Q355GNH welded joint.
An Evaluation of crushing performance of a Boride layer formed on high strength wear resistant steel
Authors: Fu Yuzhu , Tong Weiping
Published: May 2023

Boronizing treatment on the surface of wear-resistant steel can both improve the hardness and abrasion resistance of the surface layer and reduce the difference between the hardness of the boride layer and substrate, which can also greatly improve the crush performance and effeciently prevent the occurrence of brittle and fragile boronizing layer in the service process. In this paper, a boride layer without impurities was fabricated on the surface of high strength wear resistant steel (HSWRS) by solid powder boronizing treatment. The boriding behaviors of the HSWRS sample, including phase composition, microstructure, micro-hardness, wear resistance and crushing performance were investigated in comparison with those of 45 carbon steel borided at 1050 °C for 5 h. The results showed that the treated HSWRS was covered by a homogeneous boride layer. The boride layer was mainly composeded of Fe2B, V2B3, CrB2, MC, M2C. The highest micro-hardness value of the boride layer was about 1525 HV and the hardness took on gradient distribution from the surface to the center, and finally reduced to the hardness of the substrate. Compared to the borided 45 carbon steel, the boriding samples exhibit a similar surface toughness, but improved crushing performance.
Study on Microstructure and Properties of Mechanical Vibration-Assisted MIG Welded Joint of Aluminium Alloy Car Body
Authors: Gou Weijie , Wang Lihong , Zhao Liquan
Published: May 2023

The aluminium alloy MIG welding of car body has problems such as joint softening and porosity in the weld, which directly affects the welding quality of the body structure. In this study, mechanical vibration was introduced into the aluminium alloy MIG welding process as an external excitation by improving the joint microstructure and performance of aluminum alloy MIG welding. In the research process, optical microscope and scanning electronic microscope were used to observe the microstructure of the joint, observe the size of grains, detect the number of pores, test hardness, take tensile test, and study the influence of frequency of external vibration excitation on weld forming, pore distribution, microstructure and mechanical properties. Studies have shown that mechanical vibration can effectively refine the weld grain, reduce the number of weld pores, increase the penetration depth, improve the strength and hardness of the joint, and improve the welding quality of aluminum alloy. And with the increase of vibration frequency, the grain size and number of pores of the weld gradually decrease, and the penetration depth and tensile strength and hardness of the joint gradually increase.
A worm-inspired robot based on origami structures driven by the magnetic field
Authors: Jin Yuchen , Li Jing , Liu Shiyang , Cao Gongqi , Liu Jianlin
Published: May 2023

With the rapid development of origami technology, worm-inspired origami robots have attracted tremendous interest owing to their colourful locomotion behaviours, such as creeping, rolling, climbing and obstacle crossing. In the present study, we aim to engineer a worm-inspired robot based on knitting process with paper, which could realize complicated functions associated large deformation and exquisite locomotion patterns. At first we fabricate the backbone of the robot by using the paper-knitting technique. The experiment shows that the backbone of the robot can endure significant deformation during the tension, compression and bending process, and this feature ensures it can achieve the desired targets of motion. Next, the magnetic forces and torques under the actuation of permanent magnets are analysed, which are just the driving forces of the robot. We then consider three formats of motion on the robot, i.e. the inchworm motion, the Omega motion, and the hybrid motion. Typical examples for the robot fulfil desired tasks are given, including sweeping obstacles, climbing the wall and delivering cargoes. Detailed theoretical analyses and numerical simulations are performed to illustrate these experimental phenomena. The results show that the developed origami robot is equipped with such characteristics as lightweight and great flexibility, which is sufficiently robust in various environments. These promising performances shed new light on design and fabrication of bio-inspired robots with good intelligence.
Phytoplankton responses to increasing Arctic river discharge under the present and future climate simulations
Authors: Park Jung Hyun , Kim Seong-Joong , Lim Hyung-Gyu , Kug Jong-Seong , Yang Eun Jin , Kim Baek-Min
Published: May 2023

In recent decades, the unprecedented rate of Arctic warming has accelerated the high-latitude landmass hydrological cycle, leading to increased river discharge into the Arctic Ocean. This study elucidates the role of Arctic river discharge, which was the large model uncertainty in the Coupled Model Intercomparison Project 6, for the phytoplankton responses in present-day and future climate simulations by adding fresh water into the model. In the present-day climate simulation, additional river discharge decreases the spring phytoplankton biomass. Freshening of Arctic seawater facilitates freezing, increasing sea ice concentration in spring and eventually decreasing phytoplankton due to less availability of light. On the other hand, in the summer, phytoplankton increases due to the surplus of surface nitrate and the increase in the vertical mixing induced by the reduced summer sea ice melting water. In the future climate, the plankton response to the additional freshwater input is similar to the present-day climate. Nevertheless, the major phytoplankton responses are shifted from the Eurasian Basin to the Canada Basin and the East-Siberian Sea, mainly due to the marginal sea ice zone shift from the Barents-Kara Sea to the East Siberian-Chukchi Sea in the future.
Bundle theoretic descriptions of massless single-particle state spaces; how do we perceive a moving quantum particle
Authors: Lee Heon
Published: May 2023

Recently, a bundle theoretic description of massive single-particle state spaces, which is better suited for Relativistic Quantum Information Theory than the ordinary Hilbert space description, has been suggested. However, the mathematical framework presented in that work does not apply to massless particles. It is because, unlike massive particles, massless particles cannot assume the zero momentum state and hence the mass shell associated with massless particles has non-trivial cohomology. To overcome this difficulty, this paper suggests a new framework that can be applied to massless particles. Applications to the cases of massless particles with spin-1 and 2, namely photon and graviton, will reveal that the field equations, the gauge conditions, and the gauge freedoms of Electromagnetism and General Relativity naturally arise as manifestations of an inertial observer’s perception of the internal quantum states of a photon and a graviton, respectively. Finally, we show that gauge freedom is exhibited by all massless particles, except those with spin-0 and 1/2.
Near-field formation of the UCA-based OAM EM fields and short-range EM power flux profiles
Authors: Ilić Andjelija Ž , Trajković Jelena Z , Savić Slobodan V , Ilić Milan M
Published: May 2023

Orbital angular momentum (OAM) multiplexing is a recently considered solution for enhancing wireless and free-space optical communications channel capacity, whether implemented separately or in combination with existing multiplexing techniques. The theoretically infinite number of paraxially propagating and mutually orthogonal OAM modes is expected to increase the channel capacity. However, the orthogonality for different OAM modes has been shown to decrease for far link range distances, and the paraxiality of the OAM beams is not very good for small radiating sources. Based on the current knowledge, OAM beams are most likely to be used for short-range communications. Many models of the electromagnetic (EM) fields carrying the OAM neglect the fact that the OAM beam sources could be electrically large or introduce other approximations that are appropriate for far-field analysis only. An in-depth analysis of the short-range properties of OAM EM fields is still lacking. To address this problem, we propose the use of the infinitesimal (Hertz) dipole method customized for the analysis of the OAM EM fields. This technique can model the positioning and basic radiation properties of separate antennas or antenna sub-arrays that are the building blocks of OAM arrays exactly and efficiently. Similar modeling can represent the OAM sources for free-space optical communications. We focus here on the uniform circular antenna arrays and provide an in-depth analysis of what can and cannot be expected, in the best case, in their utilization. We assume low losses, which is a common assumption for many methods, except for computationally much more demanding full-wave simulations. The obtained results indicate the need to simultaneously optimize the transmission of all planned OAM modes and allow estimates of the link distances that could provide adequate OAM wave reception in various cases.
Experimental evaluation of daylighting performance and energy output of building-integrated photovoltaic (BIPV) panel in Bandung, Indonesia
Authors: Tresna D.N.A.T. , Hermawan I.M. , Mangkuto R.A. , Pradipta J. , Jamala N. , Paramita B. , Atthaillah
Published: May 2023

Building energy use contributes up to 40% of total global energy use and increases by 8-10% every five years, encouraging the development of technology-based renewable energy sources. Building-Integrated Photovoltaic (BIPV) is a potentially relevant application of integrated PV in buildings which, it provides electricity cost savings, and increases the architectural attractiveness of a building. In contrast to conventional PV installations on building roofs, vertical PV installations are significantly influenced by the building orientation and the transparency of the PV. Study and analysis were conducted to implement BIPV windows in tropical climates using experimental measurement methods in energy output and indoor daylighting in four cardinal directions. This research was done by modelling a simple 2 × 2 × 1 m3 room with a PV solar window glazing made of Monocrystalline silicon 105Wp, placed on the roof of CADL Building, Institut Teknologi Bandung, Indonesia, for four days. The measurement results indicate that South is the most recommended orientation for installing BIPV windows for tropical areas in Bandung with the performance indicators for energy output = 564 Wh, DA300 = 100%, UDI250-750 = 93%, UDI100-3000 = 100%, and UDI>3000 = 0%. In contrast, West and East orientations are not recommended because of the significant difference in energy output and illuminance in the morning and the afternoon.
Analysis of Thermal Environmental in Buildings with Water and Landscape Elements as Microclimate Modifiers in Hot and Humid Tropical Climates
Authors: Hamdy Muhammad Awaluddin , Hamzah Baharuddin , Wikantari Ria , Mulyadi Rosady
Published: May 2023

Thermal conditions in buildings are influenced by climatic conditions and are determined by the thermal performance of the building itself. The thermal condition is caused by the transfer of heat flow between the environment and the building. This study aims to analyze the value of temperature, humidity, solar radiation, and wind speed with the presence of the water element as a modifier of the microclimate in the building as well as thermal comfort for the adaptation of visitor behavior. The research focus is on the water element and the sensation of the thermal environment with public building objects. Field research based on ASHRAE 55 2020 and ISO 7730 standards. Four environmental parameters were measured, namely temperature, humidity, solar radiation, and air velocity. Data were obtained through field measurements using quantitative methods through analysis of the Predicted Mean Vote (PMV) thermal comfort index, Predicted Percentage of Dissatisfied (PPD), and Standard Effective Temperature (SET). The data is processed using a statistical approach and then simulated with 2-dimensional numerical data using the Thermal Comfort Tool (CBE) software after which it is compared with the thermal comfort index. PMV, PPD, and SET are generated and refer to the ASHRAE 55-2020 standard. Meanwhile, the sensation of the thermal environment based on behavioral adaptation was analyzed based on the results of the questionnaire answers using the thermal sensation vote (TSV). The results show that the analysis of the thermal environment in the context of the microclimate in the building, thermal comfort as well as water and landscape elements are important potentials that can provide positive values, improve quality, and maintain microclimate stability at the building scale and regional scale and need to be controlled and taken action. adaptive in buildings such as setting water elements and ventilation systems in buildings to provide a passive cooling effect on buildings.
Optimizing Bamboo as an Alternative Building Material to Respond Global Architectural Challenges
Authors: Hildayanti Andi , Wasilah
Published: May 2023

Construction industry sector is allegedly second contributing to global warming. Use of non-renewable materials a certain period of time will be exhausted and effects to environmental damage. Indonesia is rich in natural resources, including building materials, it is necessary to make a breakthrough in the realm of architecture to compensate for building this phenomenon. One possessed abundant natural materials in Indonesia is bamboo, then the chance of this study will be explored in more depth about optimizing the use of bamboo. Bamboo is flexible and strong. Indonesia has abundant availability of bamboo material, but not many architects use this material in their building designs. Bamboo grows very quickly and can be used continuously, which does not have to be produced regularly. Bamboo should be an important consideration to become the main material for durable infrastructure. Application of ecological material which is fulfilment of aspects on concept green building into a topic that continues to be studied by researchers or practitioners. Bamboo meets criteria as an alternative to application of ecological materials. Various potentials of bamboo are good elements of strength, fast growing, low energy, and materials protecting the earth’s ecosystem including economic improvement. The bamboo constraint is getting undermined by the development of modern technology. Bamboo materials can be used as ecological materials with breakthroughs in terms of modernization of bamboo utilization in the industrial context. Bamboo sustainable with happening of harmony of bamboo raw materials with culture to the current of technological progress. In order to reduce the effects of global warming and sustainable ecosystem for the future generations.