bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal performance of naturally stratified water storage tank in a power plant: a comparative study
Authors: Han Yuchen , Bai Ning , Wang Han , Li Jinghao , Zhang Jinyi
Published: March 2021

Thermal storage is one of the key technology in the transformation of thermal power flexibility. A model of naturally stratified water storage tank is established, and CFD analysis of heat release process is made. As can be seen from experimental results in a power plant, in the thermocline thickness in the tank increased from 0.43 m to 0.66 m, with an average hourly thickness of 0.06m, which has well agreement with the CFD analysis results. The effective height of the tank is 29.836m, from which we can calculate that its thermal storage efficiency is as high as 96.7%.
Impact of DG on short circuit current detected by protection
Authors: Gong Jing
Published: March 2021

DG (distributed generation) access causes the change of current detected by the protection, and then affects the sensitivity of the original protection. In order to solve the problem, the influences of DG capacity, DG access location and short-circuit location on short circuit current are analysed in this paper. When the DG capacity and grid-connected position remain unchanged, the unit current method is used to solve the short-circuit current by solving the transfer impedance. The relationship between the change of short circuit position and the impact degree of DG is discussed in detail, and the calculation formula of extreme point is derived. When the DG capacity and short circuit location remain unchanged, the impact of DG grid-connected position on the upstream and downstream current is analysed. The characteristic curve of the impact of DG position change on protection current detection is given, and the impact of DG grid-connected position on protection sensitivity is explained clearly. The conclusion provides an important reference for the selection of DG grid-connected position and the calculation of relay protection in distribution network with DG.
Analysis and design of energy storage capacity of AC-DC hybrid power distribution unit with energy storage to improve the reliability of power grid
Authors: Zhao Haibo , Zhang Zhi , Hu Ende , Li Qi , Zhao Guopeng , Zhang Youbo , Wang Dong
Published: March 2021

Based on the development of AC-DC distribution network, a new AC-DC distribution device with energy storage structure is designed in this paper. This paper first analyzes the existing AC-DC power distribution equipment and network reliability assessment methods. On this basis, the design is put forward, the energy storage link is placed at the DC high voltage side. The constraints of energy storage as an critical load backup power supply are defined and the mathematical model is established. In this paper the timing Monte Carlo method is used to calculate the reliability of the device and the power grid. The model in this paper can be applied to a variety of distribution network structure and energy storage scenarios, with high accuracy. It is concluded that the AC-DC distribution unit has remarkable effect in improving reliability.
Power flow calculation of AC / DC hybrid distribution network considering energy router
Authors: Rong Xiuting , Zhang Hui , Jia Chenyiyang , Zhao Jie , Ma Gaoyuan , He Yuqin
Published: March 2021

Energy router (ER) is the key equipment in the construction of AC / DC hybrid distribution network in the future. Based on the characteristics of AC and DC ports and topological structure of ER, a steady-state model of ER with multi ports access was established, and a power flow model of AC / DC hybrid distribution network considering ER was constructed. Newton Raphson method combined with alternating iteration method was used to solve the problem. IEEE-33 was selected to calculate and compare the circular distribution network considering ER and the traditional AC distribution network. The results show that ER can improve the voltage level of nodes and reduce network loss in hybrid distribution network.
The application of ultrasonic phased array technology in wind turbine blade defect detection system
Authors: Zhang Ningning , Bian Wentong , Pan Binbin
Published: March 2021

Start The working environment of wind turbines is complex and harsh. If the early damage of blades is not found in time, it may develop into mechanical failure under bad working conditions. Once an accident occurs, the consequences will be serious. In this paper, we study the non-destructive testing of ultrasonic phased array technique in the application of wind turbine blade defect detection, and analysis all kinds of common defects of blade production stage. According to these defects, the corresponding test device is selected, and the fault library is accumulated through defect test blocks. The original data of blade ultrasonic detection were identified, compared and finally the defect type was determined.
Optimal power and energy sizing of compressed air energy storage in distribution network using multiparametric programming
Authors: Chen Fan , Guo Zhongjie , Lin Qiyou , Xue Xiaodai , Xie Yuguang , Mei Shengwei
Published: March 2021

As a new type of mechanical energy storage, compressed air energy storage (CAES) has attracted wide attention in recent years. This paper studies the optimal sizing problem of CAES in power distribution network (PDN). CAES plays a role in shaving the peak and filling the valley at demand side and thus reduces the operation cost of PDN to purchase electricity from the main grid. A multi-parametric linear programming (MP-LP) model is formulated where the power and energy capacities of CAES are regarded as parameters; the parameterized optimal value function (OVF) provides a graphical tool to describe the impact on operation cost of CAES configuration, which helps determine the planning strategy in a visual manner. The visualized results reveal not only the optimal solution, but also some useful information, like the sensitivity of operation cost to parameters. Case studies conducted on the IEEE 33-bus distribution system verifies the effectiveness of the proposed method.
Phase delay solution based on instantaneous reactive power theory
Authors: Zhao Mengzhen , Zhang Jie , Zhang Xin , Zhou Wandong , Xu Anfei
Published: March 2021

According to the theoretical detection method of instantaneous reactive power, the paper proposes a harmonic current detection method based on the combination of synchronous rotating coordinate system and PI control. This method adds PI adjustment after the filtering link to accurately track the current amplitude, realizes zero error control, and performs phase compensation on the rotating coordinate system to compensate the fixed phase delay time of the filter, so as to achieve the accuracy of the harmonic detection link. The analysis of the experimental results shows that the improved harmonic detection method is equally effective under the three-phase symmetrical load and three-phase asymmetrical load. Under three-phase symmetrical load conditions, the improved harmonic detection method reduces the THD of the grid current by 0.72% compared with the original method. Under three-phase asymmetrical load conditions, the improved method reduces the THD of the grid current by 0.11% compared to the original method.
Research on the hybrid energy system of electric vehicle
Authors: Zhou Shiqiong , Sun Jing , Kang Longyun
Published: March 2021

In order to solve the negative problems of environment and energy caused by fuel vehicles, the application of new energy sources in the field of automobiles has gradually become the focus of attention. A hybrid energy system of electric vehicle was studied, which is composed of ultracapacitors(UCs), solar panel (namely PV) and lead-acid battery set. Through the research, it was found that the maximum power tracker can track the maximum power point of the solar panel, and the ultracapacitors with high power density and the battery with high energy density can be complementary by each other, shorten the discharge time of high current and improve the dynamic performance of the vehicle.
The impact of load transfer on transmission and distribution costs
Authors: Gan Zishen , Jing Zhaoxia
Published: March 2021

This article analyses the impact of the load transfer on the transmission and distribution costs from the N-1 security check of the distribution network and the total supply capacity, and proposes a capacity expansion planning model for the distribution network to obtain the best investment time for the generator, and then further studys the impact on the cost of transmission and distribution after the expansion of the distribution network.
Study on rural electrification policies and demonstration projects in China
Authors: Li Min , Zhang Xuan , Zhao Guan , Ma Junhua , Meng Hao , Xu Shuangqing , Yan Xing , Wang Lei , Huang Wenrui
Published: March 2021

This study aims to further promote rural electrification, optimize the rural energy structure, eliminate poverty among farmers, improve the rural energy efficiency, and achieve an overall well-off and rural revitalization strategy. Shouguang City of Shandong Province, is one of the largest vegetable distribution centres in China and has good policy conditions. This paper examines four types of rural electrification demonstration projects in Shandong Province We have extracted the “Shandong Shouguang Model” with standard construction mode, advanced application technology and complete local policies. The “Shandong Shouguang Model” includes “Four Ones”: “One Platform”, “One Model”, “One type of business” and “ One set of standards” for rural electrification construction, and provided Cost-price and Investment-tax relief policies for rural electrification development across the country. Replicated experience. Promote the achievement of 100% energy cleanliness and 100% end-energy electrification through the construction of Zero-carbon emission demonstration zones and Net-zero energy consumption.
Optimal operation of a multi-energy hub for minimal energy usage cost
Authors: Liang Jianquan , Huang Rui , Wang Panbao , Zhang Jian , Sun Wei , Xu Dianguo
Published: March 2021

This paper proposes a management model of a Multi-Energy Hub (MEH), which is an essential part in the Energy Network. Energy Hub (EH) is a collection of various energy conversion devices and energy storage elements. It can be regarded as the transmission node in the Energy Internet. In this paper, an EH containing Combined heat and power (CHP), electrical heat pump, electricity storage system and heat storage system is studied. In this paper, a new EH model is proposed which is different from the modelling method based on the original EH concept. The proposed method focuses on the practical application field. The optimal model and management of the proposed EH components focusing on the minimal energy usage cost is modelled as a mixed-integer non-linear optimization problem calculated by General Algebraic Modelling System (GAMS) software. Also, in order to be closer to the practical application, the electricity storage system optimization has been considered. The battery life loss is equivalent to the daily energy storage loss cost. The simulation results show that the proposed model is more economical than the traditional model and the maximum depth of discharge (DOD) has less influence on the battery life. However, value of maximum DOD effects the operational cost.
Environmental information disclosure of textile and garment enterprises
Authors: Shao Pengfei , Li Yiyi , Yao Lei
Published: March 2021

As the government, society, public and other stakeholders pay more attention to environmental protection, enterprise environmental information disclosure has gradually become a hot issue in theoretical research. Textile and garment industry is an important part of China‘s national economy, but in its development process, there are very serious environmental pollution problems and governance difficulties. In this paper, the textile and garment industry listed enterprises as the research object, through the investigation of the environmental information disclosure of annual reports, independent reports and other four years from 2015 to 2018, set up the rating scale, analyze the current situation of environmental information disclosure, explore the existing problems, and put forward corresponding measures to improve, so as to make up for the ecological environment weaknesses of China‘s textile and garment industry as soon as possible.
Development and prospect of lignite burning power generation in circulating fluidized bed boiler
Authors: Xin Shengwei , An Fengxia , Bai Jiliang , Han Ping , Zhang Peng , Duan Caili , Hao Qianjun , Cao Peiqing , Wang Hu , Gu Congyang
Published: March 2021

At present, direct-combustion of lignite for generating electricity is a meaningful way to utilize lignite. The development status of lignite power generation and lignite CFB boiler technology is introduced in this paper. From the aspects of combustion stability, boiler efficiency and pollutant discharge, the technical and economic comparative analysis of lignite power generation technology of pulverized coal boiler and CFB boiler is carried out. As a result, CFB boilers burning lignite have more advantages than pulverized coal boilers in combustion stability, boiler efficiency, and pollutant emission reduction. The development of 600-1000MW ultra-supercritical CFB boiler units burning high moisture lignite is feasible and has certain strategic advantages.
A novel approach to evaluate the benefits of price-based demand response in the unit commitment problem
Authors: Wang Huiji , Yue Hao , Zheng Yanan
Published: March 2021

Price-based demand response (DR) has been widely accepted as playing an important role in the reliable and economic operation of the power system. There are different ways to quantify the electricity consumption experience (i.e., comfort) of customers, which can be divided into positive and negative benefits, that is to say, there is no unified method to evaluate the positive or negative benefits of DR. Based on the self-elasticity and cross-elasticity of price elasticity of demand (PED), this study first addresses a novel approach to evaluate the positive and negative benefits of price-based DR with the consideration of customers’ electricity consumption experience. Then, a unit commitment (UC) model considering priced-based DR is built to analyse the influence of priced-based DR on the power system operation, which is linearized into a mixed integer linear programming problem. Finally, the propose method and model are verified the effectiveness through analysing the influence of self-elasticity and cross-elasticity on the power system operation in the IEEE RTS79 system.
The research of source-load transaction mechanism based on blockchain
Authors: Sun Yong , Chen Yongquan , Li Dexin , Lu Hengcong , Li Baoju , Liu Chang , Lu Wen
Published: March 2021

With the development of distributed renewable energy and the energy Internet, the cost of distributed energy participating in traditional power transactions continues to rise, and there is an urgent need for more reasonable transaction mechanisms and efficient information technology to improve the efficiency of distributed energy transactions. The characteristics of blockchain technology are in line with the transaction needs of distributed renewable energy, and it has development potential in energy transactions. Based on blockchain technology, this paper designs a source-load transaction mechanism in which the virtual energy medium is the equivalent of the intermediary. This mechanism can avoid the problem of credit asymmetry between buyers and sellers. We design from three aspects: transaction, payment, and settlement, and verify the actual application. The results show the feasibility and effectiveness of the transaction, provide a new way for multi-frequency and small transaction volume of new energy transactions, and provide new solutions for the consumption of new energy such as photovoltaics and wind power.
XLPE cable health assessment based on Relief-F feature weighted FSVM
Authors: Wu Xiaohuan , Liu Yang , Wang Liqun , Ren Xinzhuo , Tan Xianjun
Published: March 2021

For the cross-linked polyethylene (XLPE) cable health status assessment process, there are noise data for each feature parameter and the importance of each dimension feature is difficult to determine, which leads to deviations in the cable status assessment results. An XLPE cable health assessment algorithm based on Relief-F feature weighted fuzzy support vector machine is proposed. The Relief-F algorithm is used to calculate the importance of each dimension feature. The feature quantity that is weakly related to the evaluation of the health status of the XLPE cable is deleted. Furthermore, the fuzzy support vector machine is used to evaluate the health status of the XLPE cable, which gives the noise data a smaller degree of membership and reduces the influence of the noise data on the evaluation results. Experimental analysis shows that this method can accurately assess the health status of XLPE cables. It can provide a reference value for relevant departments to carry out cable maintenance and replacement work and save the human resources, and material resources required for maintenance and replacement of cables.
Local feeder automation under mode of customer power supply priority
Authors: Yan Lijuan , Ou Shifeng , Li Kewen , Chen Qianyi , Chen Shaonan
Published: March 2021

The local feeder automation method (LFA) is applied in the single side power distribution system. The protection and re-closing of substation outgoing line are used to coordinate with the time limit characteristics of voltage-time type switch to isolate fault and recover power supply automatically. The access of small hydro-power (SH) makes the distribution system present multi power pattern. In this paper, based on LFA considering SH access, in order to achieve the goal that SH can operate in isolated network with load after fault, LFA under the mode of customer power supply priority (LFAUP) with adaptive opening time for switch is proposed. When the fault point is located on the grid side of the quasi power balance switch (QPBS) and the isolated network is on its load side, the switch can automatically isolate all types of short circuit fault from the load side without residual voltage locking (also known as X locking). When the power of the isolated network is balanced, the loads in which will not get power failure. Simulation results show LFAUP advanced in the paper is correct and feasible.
Research on change detection of high resolution remote sensing image based on U-type neural network
Authors: Li Congyi , Kong Xiangbing , Wang Fuling , Wang Yinan , Zhang Mengxuan
Published: March 2021

The change detection of high-resolution remote sensing images has always been a research difficulty and hot spot, which has a great application demand in land use change and ecological environment monitoring. U-type neural network can train a better model with less samples, and has good experimental effect in medical image segmentation, but it is rarely used in remote sensing image change detection research. In this paper, the U-type neural network is used to detect the change spots in GF-1 image of Yuzhou City, Henan Province, and compared with FCN, SegNet and Siamese-CNN. Experimental results show that the F1 score of U-type neural network model are 0.699 and 0.66 respectively, which are better than the other three methods, and the omission is lower, which is closer to the label map. Therefore, it is feasible to use U-type neural network for change detection of high-resolution remote sensing images, and it can have high detection accuracy.
Fire frequency analysis and prediction based on back propagation neural network model and Long-Short Term Memory model
Authors: Hu Xinyue
Published: March 2021

It is reported that there have been many fires in many places this year. This article wants to explore the factors affecting the occurrence of fires and make predictions to prevent the occurrence of forest fires. The correlation between forest indexes and fire frequency in Fujian, Guangxi, Heilongjiang, Hunan, Sichuan, Yunnan and Zhejiang provinces was analyzed based on forest indexes and fire frequency prediction in seven provinces from 1998 to 2018. According to the six relevant indexes of seven provinces in 20 years, the Pearson correlation coefficient between them and the number of fires was analyzed to find the correlation between the variables. The Grey system theory Model (GM (1, 1)) was established to predict the six related index values. The BP neural network model was established based on the historical and the predicted values were substituted into the Back Propagation (BP) neural network model to predict the number of fires. Then, a prediction model based on Long-Short Term Memory (LSTM) was constructed through deep learning library Keras, and the predicted value was substituted into the model to predict the number of fires. Zhejiang Province and Hunan Province were taken as examples to compare the accuracy of the two models’ predictive values. It was found that the LSTM model had better fitting effect, and the LSTM model was finally used to predict the number of future fires. The forest ecological risk identification and prediction system based on Graphical User Interface system (GUI) was developed, the phase space reconstruction of one-dimensional data with time series characteristics was carried out, and the high-dimensional data were trained by using fuzzy neural network to realize data prediction and evaluation. This prediction can be applied to the forest prevention and control departments, and the annual fire situation can be predicted based on historical data, so as to prevent and reduce losses in advance.
The mechanism of NAPL layer formation in a microfluidic device with dual-permeability: experiments and numerical simulation
Authors: Wang Xiaopu , Wang Xu , He Tianhao , Li Yan , Hou Lianjie
Published: March 2021

In-situ remediation is an important technique for non-aqueous phase liquid (NAPL) contamination remediation in soils. Understanding the formation and distribution of NAPL contaminated layers in heterogeneous soils is essential to propose cost-effective remediation methods. Therefore, a two-dimensional microfluidic device with dual permeability zones was designed to simulate the soil-groundwater system and experimentally investigated the formation process of the NAPL contamination layer. Numerical modeling of phase field coupled with laminar flow was used to simulate the distribution of NAPL in soil-groundwater system, and the formation of NAPL contamination layer under typical groundwater flow rate and wetting angle was evaluated. The NAPL in the low permeable zone formed a stable contamination layer, while the NAPL in the high permeable zone was washed out to varying degrees and mainly resided in the junction of high-low-permeability regions of the chip, with residues of 42.2% and 23.3% in the chip high permeable region at groundwater velocities of 6.17 m/d and 10.16 m/d, respectively, the numerical simulation results were consistent with the experimental observations. This retention was diminished in the high permeable zone as the NAPL-to-wall wetting angle increased. In addition, when the contact angle was increased from 33° (lipophilic) to 108° (hydrophilic), the residual NAPL content in the high permeable zone decreased from 48.86% to 28.22%. This paper provides a reliable visualizable experimental platform for the study of NAPL pollution formation at micro-scale in heterogeneous groundwater system, and lays a foundation for the subsequent optimization of the remediation strategy.
Recent advances in g-C3N4-based photocatalysts for reduction of CO2
Authors: Li Fangqin , Sun Chenhao , Ren Jianxing , Wang Guanjun , Chen Mengping , Sun Haijie , Wang Ze , Li Henan
Published: March 2021

The key to reduce the concentration of CO2 in atmosphere by using the photocatalytic reduction method lies in the development of low-cost, stable, and environmentally friendly photocatalysts. Given that g-C3N4 has the advantages of non-toxic, no metal elements, narrow band gap, good thermal stability and so on, analysis shows that this is a very potential photocatalyst. However, at present, the photocatalytic efficiency of pure g-C3N4 is limited by small specific surface area, low visible-light utilization efficiency and high recombination rate of photogenerated charge carriers. In this review, we report the methods for improving photoactivity of the g-C3N4, for instance, loading precious metal cocatalysts, earth-abundant metal cocatalysts and non-metallic cocatalysts. Finally, the issues that should be paid attention to when further studying the photoreactivity of g-C3N4 and its future research directions are discussed.
Study on degradation of reactive brilliant red X-3B by three-dimensional biofilm electrode reactor
Authors: Liu Shentan , Xue Hongpu
Published: March 2021

The treatment of azo dyes by three-dimensional biofilm electrode reactor (3D-BER) has the characteristics of fast decolorization, high mineralization efficiency and less sludge production and has broad application prospects. The 3D-BER was constructed by filling granular activated carbon (GAC) as a third bipolar electrode in the cathode chamber of conventional BER, and it greatly improved the degradation property of reactive brilliant red (RBR) X-3B. The effects of dye concentration, operating voltage, hydraulic retention time (HRT) and nitrate content on the stability of the experiment were investigated. The results reveal that azo dyes were first decomposed into aromatic amines such as aniline at the cathode, however, the amine substance was difficult to be biodegraded in the anaerobic cathode area, and then the decomposition products of aromatic amines reached the anode region and were further metabolized. Moreover, the water samples were analysed by FTIR and UV-Vis analysis. It was noted that the double bond of the azo dye was broken and degraded into aromatic amines, which were further effectively degraded.
Pyrolysis kinetics of filter mud from sugar mills
Authors: Liang Yong , Liu Faqiu , Liu Lei , Xiang Min , Zhou Shaoji , Zhao Zhengang
Published: March 2021

In order to facilitate the possible reuse of filter mud from sugar mills as boiler fuels or producing biochar that involves pyrolysis process, thermogravimetric analysis (TGA) was emploied to analyze the pyrolysis kinetics of it. In TGA tests, filter mud were heated from 30 °C to 800°C at different heating rates (5, 10, 15, 20, 25 and 30 °C/min) in the atmosphere of nitrogen, and the relevant parameters of kinetics were performed by methods of Flynn–Wall–Ozawa (FWO) and the Kissinger–Akahira–Sunose (KAS). The results shown that the average activation energy analyzed by FWO and KAS were 322.28 and 321.93 kJ/mol, the average enthalpy were 289.04 and 288.24 kJ/mol, the average Gibbs free energy were 207.87 and 208.01 kJ/mol, respectively, the pre-exponential factors varied in the range of 1022–1039 s-1.
Residual life evaluation of 12Cr1MoVG steel for main steam pipeline
Authors: Tang Ping , Huang Shengpeng , Tian Wei , Ling Zhangwei , Jin Nanhui , Li Feng
Published: March 2021

12Cr1MoVG steel is a commonly used steel for boiler main steam pipes. With the increase of service time, the material’s endurance performance is deteriorating. In this paper, the performance analysis of the 12Cr1MoVG steel main steam pipe which has spheroidized and deteriorated after 70,000 hours of service in a power plant was carried out, and the residual life of this pipeline was evaluated. According to the evaluation, the residual life of the pipeline is more than 100000 hours.
Fault diagnosis model of refrigeration system combining Boruta and LightGBM methods for energy saving
Authors: Li Zhengfei , Hu Kuan , Chen Huanxin , Liu Qian
Published: March 2021

Energy consumption of HVAC system accounts for a large proportion of building energy consumption, and it is necessary to improve the energy efficiency of the system to achieve the purpose of energy saving. Once the HVAC system malfunctions, the energy efficiency of the system will decrease, resulting in unnecessary energy waste. Aiming at common failures of refrigeration systems, this research proposes a fault diagnosis model combining Boruta and LightGBM methods to diagnose faults in time. The results show that compared with other three tree-based models, this optimized LightGBM model can not only efficiently diagnose the refrigerant charge amount faults of the VRF system, achieving a fault diagnostic accuracy of 97.52%, but also can be transplanted to other systems for fault diagnosis, thus effectively avoiding unnecessary energy waste caused by those failures.
Review on polymer flooding technology
Authors: Li Xuening , Zhang Fusheng , Liu Guoliang
Published: March 2021

In this paper, the research status of polymer flooding in China and abroad in recent years is reviewed, as well as the mechanism and application of polymer flooding are described. The research progress of several commonly used polymer flooding agents are introduced, including biopolymer, temperature and salt resistant monomer polymer, hydrophobic associating polymer, cross-linked polymer, comb polymer and star polymer. Based on the analysis of the properties, advantages and disadvantages of these flooding polymers, some suggestions are given for the problems existing in the current application of the polymer flooding technology. Also, suggestions of research direction of polymer flooding agent in the future are shared.
Numerical simulation of gas wells in different types of carbonate reservoirs
Authors: Dong Jiaxin , Shi Wen , Xu Mengya
Published: March 2021

The geological conditions of carbonate reservoirs are complex, and there are multi-media of pores, vuggy, and fractures with different scales. The macroscopic Heterogeneity of carbonate reservoirs is very strong, and the difference between wells is very large, which leads to the great difference in the production of different types of reservoirs and the difficulty in product evaluation. It is also difficult to forecast the production capacity and to determine the policy of developing technology. In this paper, by using the actual data of the Moxi area, the reservoir types of Moxi area are defined, and the production performance of different types of reservoirs are revealed. By using the integration of unconventional geological modelling and numerical simulation software Untog, the geological models which can reveal the geological characteristics of different types of reservoirs are established, and the numerical simulation study is carried out. The contribution of different media to the well production is revealed, the larger the pore size, the higher the recovery degree. Higher the proportion of large-scale pore, the higher the gas well production, and higher the well recovery.
Optimization design and application study on a high temperature resistant borated polyethylene shielding material
Authors: Li Xiaoling , Yu Ming , Xu Xiaohui , Wu Rongjun
Published: March 2021

This paper carried out an optimization design and application study on a high temprature resistant borated polyethylene shielding material, according to the nuclear power plant source characteristics and special protection requirements. The composition of borated polyethylene shielding material was optimized based on the genetic algorithm and Monte Carlo methods, then it was realized by blending modification and graft copolymerization to improve the high temperature resistant, shielding and mechanical properties. Finally, comprehensive properties such as mechanical, neutron shielding, irradiation resistance and high temperature resistance experiments were verified with the ordinary borated polyethylene and polypropylene. Those just proved the optimized borated polyethylene shielding material has excellent performance comparatively, especially it could keep complete structure in a high temperature environment up to 190°C during 48 hours, meeting the requirements of radiation protection safety for nulear power plant completely.
Analysis of Q-switched effect of LiF: F2
- crystal in long pulse width solid state laser
Authors: Sun Yan
Published: March 2021

LiF: F2
-crystal is used as Q-switched crystal in a pulsed adjustable laser system to realize passively Q-switched dynamic laser output. The output laser waveform is a series of sub-pulses, the width of the sub-pulses is nanoscale, the repetition frequency is 3.3kHz, and the average power is relatively high. In this paper, the characteristics of experimental law are analyzed. Combined with the metastable energy level characteristic of LiF: F2
-crystal, the reason why the long pulse width laser can output pulse train is explained.
Effect of Long-Distance Earthquake from Philippines and Sulawesi to Sabah Region
Authors: Harith N S H , Tongkul F , Adiyanto M I , Rizalman A N
Published: March 2021

Sabah is known for its active earthquake activities, especially in Ranau, Kudat and Lahad Datu areas. The effects of local earthquake can reach M
W
6.0. Furthermore, Sabah was also hit by earthquakes from neighbouring countries such as Sulawesi and Philippines. These countries produce highly active earthquakes that can reach as high as M
W
8.6. The increase in the frequency of earthquakes is one of the concerns of the Sabah government for the safety of its people because most people live in concentrated areas near the coast. This study shows the effects of major earthquakes from the Philippines and Sulawesi which have been recorded between 1900 to 2020 and analyzed in terms of peak ground acceleration (PGA). The eastern region of Sabah is adopted in the analysis for the effect of long-distance earthquakes, as these areas are close to both countries. The analysis uses standard seismic hazard assessment procedure with compilation magnitudes greater than M
W
5.0. In the final analysis, it is shown that the effects of large earthquakes from both countries are relatively small compared to the effects of local earthquakes.
The effects of particle breakage and shape on the strength parameters of sandy soil
Authors: Youventharan D , Rokiah O , Mohd Arif S
Published: March 2021

Many laboratory and full-scale studies found that pile foundation is a reliable structure that has a long-term durability. This aspect makes it favourable when construction is in an area like the coastal where granular materials are normally in great scale. Generally, method used for the installation of pilling such as the drop hammer method will involve high energy to drive a single pile into the ground. Hence, the soil particles may undergo serious physical changes that will affect the engineering properties of soil used in the design work. The main aim of this research is to know the impact of pile installation work on sand particles. To understand the impact of sand particle breakage to the soil strength, an actual soil breaking mechanism simulated in the laboratory by using an automated soil compactor where the sand samples were crushed using 500 and 1000 times of blows respectively. The behaviour of sand were then analysed using a series of test which are; sieve analysis, specific gravity, relative density and the shear box test in order to measure the engineering properties of the sand. Mackintosh probe test was conducted in-situ to identify the undrained shear strength of sand and to correlate the cohesion of the sand with laboratory testing. This research confirmed that particle breakage has a significant influence with sand shape and therefore its strength changes with crushing impact.
Performance of asphalt mixture incorporated with tin ore tailing
Authors: Yuan L , Masri KA , Ramadhansyah P J , Razelan I S M , Norhidayah A H , Mohd Warid M N
Published: March 2021

Tin Ore tailings (TOT) are waste generated from tin mining activities, which not only occupy lots of land, but also result in severe pollution to the surroundings. Many studies by researchers exploring better ways to increase the usage of industrial by-products in order to ease disposal problems preserve natural sources and save the environment. In this study, 1%, 3% and 5% of TOT are incorporated with ACW14 mixture in accordance to JKR 2008. 5% optimum bitumen is used for all samples. Marshall Mix design test is conducted to determine the volumetric properties, stability and flow. Moisture susceptibility test conducted to determine the indirect tensile strength in dry and wet samples. Generally, the stability values increases with the percentage of TOT increased.
Resilient modulus prediction of nano-silica modified porous asphalt using Finite Element Analysis
Authors: Al-Akhshar A M , Masri K A , Ramadhansyah P J , Norhidayah A H , Mohd Warid M N , Yaacob H
Published: March 2021

Repetitive traffic load is the most important factor influencing porous asphalt (PA) performance. The performance of asphalt is mostly influenced by the loading magnitude of heavy vehicles. In order to improve the service performance of PA under heavy traffic conditions. the decrement of stiffness is one of the failures that occur on the PA which mainly caused by the repeated load from a large number of different types of vehicles which leads to reduce the characteristic of PA in terms of stiffness and durability. Moreover, to enhance the performance of PA against the stiffness reduction an additive material used to increase the strength of the PA called Nano-silica particles. Thus, the aim of the study to investigate the resilient modulus of Nano-silica modified PA and develop a finite element analysis FEA model to predicate the resilient modulus. In this study, three different Nano-silica contents 0%, 2% and 4% by weight of PA mixture were investigated. To achieve this, a finite element model was developed and simulated by using ABAQUS 6.14 software for the PA samples to predict the resilient modulus performance. A comparative study was done among the unmodified and modified PA mixtures considering the resilient modules value. The result showed that Nano-silica is recommended as an additive in PA mixture, as the result of the modified PA mixture with 2% of NS was 4357Mpa while the unmodified was 3001Mpa. Thus, the addition of NS to PA mixture Capable in increasing the strength and quality of asphalt mixture.
Spatial-Temporal Change in Vegetation Cover and Climate Factor Drivers of Variation in the Haihe River Basin 2003-2016
Authors: Li Jingwen , Su Zhipeng , Jiang Jianwu , Chen Wenda , Yu Na , Li Xu , Xie Jiali , Wei Jingshan
Published: March 2021

In order to study the correlation between the annual dynamic change characteristics of vegetation and climatic factors in Haihe River Basin in recent 14 years. The MODIS / NDVI data from 2003 to 2016 were used to extract the vegetation coverage of the Haihe River Basin. driver of NDVI changes in the Haihe River basin. The one-dimensional linear regression was used to analyze the trend of temporal changes of vegetation in the Haihe River Basin, and the trend analysis and correlation analysis of vegetation climate change were performed by combining the data of precipitation and temperature meteorological data from 2003-2016 in the Haihe River Basin. The study shows that the overall vegetation cover in the Haihe River basin is relatively high, and the cover type is mainly high, and the NDVI increases significantly at the rate of 0.021/10a; the spatial vegetation change trend in the Haihe River basin is mainly improvement, accounting for 94% of the basin area; climatic factor correlation analysis shows that precipitation is the main factor influencing the change of NDVI in the Haihe River basin.
Study on the Circulation of Agricultural Products Based on Cloud Computing from the Perspective of Rural Revitalization Strategy
Authors: Zeng Yitang , You Meihong
Published: March 2021

The construction of modern circulation system of agricultural products is an important content to promote the prosperity of rural agricultural industry and the implementation of rural revitalization strategy. In practice, the main modes of agricultural products circulation include wholesale market type, agricultural super-docking type, farmers market type and network platform type, each mode has its own advantages and disadvantages. From the perspective of the implementation of rural revitalization strategy, there are still some problems in the circulation of agricultural products at present, such as high circulation cost, facilities are backward, professional brokers is in the ascendant, the level of information service is low, fund shortage. At the same time, there are some new trends, such as high growth to high quality development, orderly circulation system of agricultural products under national macro-control, efficient, safe, healthy, green and intelligent ecological development, "pyramid" agricultural product market system with Chinese characteristics, and so on. It is necessary to speed up the circulation of agricultural products based on cloud computing from six aspects: innovative trading mode, innovative supply and demand mode, innovative distribution mode, innovative organization mode, innovative product brand and innovative operation mechanism, so as to lay the foundation for realizing the strategy of rural revitalization.
Study on the Compressive Elastic Modulus and Poisson’s Ratio of Tobacco Main Veins
Authors: Yu Jie , Chu Jinkui , Li Yang
Published: March 2021

Mechanical properties of the tobacco main veins are basic parameters for the design of tobacco leaves harvester. And the compressive elastic modulus and Poisson’s ratio of tobacco main veins are related to the contact force between the tobacco leaves and the harvesting tool, which is an important design parameter for tobacco leaves harvester. In this work, lateral compression tests were carried out on tobacco main veins. And the force-displacement equation during lateral compression was derived based on the Hertz contact theory. Then the compressive elastic modulus and Poisson’s ratio were obtained by the method of piecewise nonlinear fitting. The fitting results of Poisson’s ratio are in the range of 0.33 to 0.56. The fitting results of the compressive elastic modulus are in the range of 1.30MPa to 3.07MPa. And the compressive elastic modulus increases with the increase of strain.
Submillimeter Crack Detection Technology of Eggs Based on Improved Light Source
Authors: Chen Haokang , Ma Jia , Zhuang Qiangjian , Zhao Shuaitongze , Xie Yuanliang
Published: March 2021

The purpose of this paper is to provide an effective method for detecting submillimeter crack in eggs. The central idea is to enhance the crack information, because the submillimeter crack information is easy to be lost. Different from the pressure method used in previous literatures, this paper improves the light source for image acquisition. The laser light source is placed on the back of the egg, and the crack information is enhanced by the feature of high laser brightness. But the resulting problem is that stomata and eggshell edges are also noisier. To solve this problem, this paper comprehensively utilizes the characteristics of fixed threshold and adaptive threshold methods. The feature of fixed threshold is that it can select global threshold to eliminate the edge noise of eggshell with small pixels, but the stomatal noise is larger. The characteristic of adaptive threshold is that it can reduce the stomatal noise but keep the edge noise. According to the above analysis, this paper applies the two methods to obtain two result images at the same time, and performs and operates on the result image to filter the noise of egg stoma and eggshell edge, and determines whether there are cracks based on the standard of area. In the experiment, 100 eggs were tested, and the recognition of tested, cracked and comprehensive eggs reached 90.0%, 92.0% and 91.0% respectively. The innovation of this paper is to enhance the crack information in essence by improving the light source, instead of improving the recognition degree only by improving the algorithm. The comprehensive use of fixed threshold and adaptive threshold is also one of the innovations of this paper. Previous journals only improved or compared one threshold selection method, but did not make comprehensive use of their advantages.
Study on Physiological Changes of Seed Broccoli under Salt Stress
Authors: Zhou Yong , Peng Yanjie , Liu Zhong , Huang Jiao , Zheng Ying , Wang Yu
Published: March 2021

In this paper, the typical neutral salt NaCl in salt soil was used to simulate salt stress. The changes of CAT, H2O2, POD, proline, total SOD and leaf thickness of H17, a seed broccoli variety, under the concentration of 100, 200 and 300 mmol/L NaCl were detected at water sensitive stage of seed broccoli. The results showed that the total SOD activity of seed broccoli was not significantly affected, and the activity of POD was more sensitive to low salt stress (100 mmoml/L). The activity of POD remained basically stable when the salt concentration continued to increase. The activity of CAT showed a tendency to decrease first and then rise. The H2O2 and proline exhibited more sensitive to low and moderate salt concentration with a trend of rise first and fall then. The content of H2O2 and proline reached the peak at middle salt concentration (200 mmol/L). Additionally, the leaf thickness was positively correlated with salt stress concentration.
Study of retention and infiltration wells as a result of resettlement of the Batang Kuranji upper watershed
Authors: Ophiyandri T , Istijono B , Gromiko A , Hidayat B , Junaidi  , Nulrajabmil
Published: March 2021

Padang City is one of the metropolitan cities in West Sumatra Province and has six (6) watersheds, one of which is the Batang Kuranji watershed. Over the last few years Batang Kuranji watershed has experienced significant infrastructure and urban development which began with the massive earthquake of 30 September, 2009 with coastal communities, afraid of being affected by larger aftershocks having the potential of a tsunami, moving to the upper watershed. As a result, the type of land cover that was originally an infiltration area has been changing into a runoff area. The Batang Kuranji channel with a discharge (Q25) 870 m3/s may not be able to accommodate the change in discharge which can lead to flooding. This paper aims to determine changes in discharge that occur due to changes in land cover and to analyse whether the use infiltration wells and retention pond can reduce the flooding volume. Two methods to calculate runoff discharge were adopted, HEC-HMS 4.1 Modelling and Nakayasu. It was found that the peak discharged increases to (Q25) 1,037.60 m3/s. Thus, creating retention pond with a dimension of 35 hectare with a depth of 5 m and 34,246 infiltration wells can reduce the flood risk. The percentage of runoff discharge they can accommodate is 90.98% and 9.02% respectively.
Effect of lumped mass on the structural dynamic modifications of a structure
Authors: Bahari A R , Yunus M A , Rani M N A , Jasmin N
Published: March 2021

The identification of the effectdue to structural changes using modal data is very challenging in the structural dynamic modifications (SDM) study. In this paper, the aim of this studyis to identifythe effect of physical changes of a structural system based on the natural frequencies and mode shapes. A mild steel thin plate structure was used in the study. A mass was attached to the thin plate to alter the dynamic characteristics of the thin platestructure. Experimental modal analysis (EMA) and the normal modes analysis wereperformed in two stages to the thin plate structure, without mass and the mass is attached to the thin plate structure. The normal modes of the thin plate structure were obtained using finite element (FE) analysis. The results of the natural frequencies and mode shapes between the thin plate and thin plate with SDM were compared. It is concluded that the impact of structural changes due to SDM will change the modal parameters of the structure.