bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of Estimation Accuracy of Body Motion Based on Muscle Potential Signal
Authors: Shingo Yoshino , Shoshiro Hatakeyama , Masami Iwase , Jun Inoue
Published: April 2020

The purpose of this research is to develop a man-machine interface that changes machine impedeace based on surface myoelectric potential. The impedance model of the wrist joint is constructed from the measured data to derive the moment of inertia, viscosity coefficient and rigidity of the human’s wrist joint, investigate the relationship between human joint impedance and electromyography (EMG), according to the change of EMG from the relationship, We have developed an interface to change the mechanical impedance of the robot arm. We investigate the relationship between human joint impedance and EMG, and apply the sparse modeling method to the modeling process. We have created an interface to change the mechanical impedance of the robot arm based on the model.As a result, myoelectric potential and force data have been acquired. Also, mechanical impedance has been acquired.In this study, we improve the estimation accuracy of physical motion by selecting characteristic parameters and terms using sparse modeling, which is considered to be feasible by estimating the force that occurs at the same time as the position at the time of physical movement.
Advanced Driver Assistance Based on Front-View and Rear-Side-View Scene Analysis
Authors: Cheng Hsu-Yung , Yu Chih-Chang
Published: April 2020

This paper proposes a high-performance advanced driver assistance system that analyses front-view driving scenes and rear-side-view scenes. Dense optical flow analysis is calculated for both views to extract motion information. The system performs ego-lane position identification via an effective fuzzy system and indicates if the vehicle is driving on an inner or outer lane. Extracted flow intensities are utilized as the input for deep convolutional neural networks to issue warning events. The front-view event warning system is more responsive to various types of potential approaching dangers because there is no need to detect vehicles first. The rear-side-view scene analysis provides safety check for vehicle doors. Optical flow information and neural networks are also used for rear-side-view scene analysis. The experimental results have shown that the proposed methods can effective detect events or dangerous conditions and help increase the safety of the drivers and road users.
Study on Regional Division of Air Traffic Management in Mainland China in the Future
Authors: Hua XIE , Ye WANG , Minghua Zhang
Published: April 2020

With the problems of poor coordination and frequent flight delays among major air traffic control regions in mainland China becoming increasingly prominent, a series of air traffic control reform measures are imperative. In order to meet the development need of the transition from a large civil aviation country to power one in the future, it is necessary to divide the air traffic management regions reasonably in advance. Therefore, based on the flights between the airports from 2011 to 2017, this paper combines the grey prediction algorithm with the gravity model and considers the impact of high-speed rail on the flights of civil aviation, then constructs the grey gravity prediction model. According to the forecast result of the future airport flow by the grey gravity prediction model, the flight plans of each airport are generated by using the equal proportion enlargement method. On the basis of the flight plans of each airport, the flight situation in mainland China at a certain time is simulated. According to the simulated aircraft longitude and latitude data, the optimal clustering results are obtained by using the fuzzy C-means clustering algorithm and clustering validity evaluation index. Finally, the clustering results are processed by clustering boundary recognition algorithm, the future air traffic management regional division results in mainland China are obtained. The experimental results show that the prediction accuracy of the grey gravity prediction model considering the influence of high-speed rail is better than the traditional grey prediction algorithm, and the original seven major air traffic control zones in mainland China are re-divided into three major air traffic control zones: North China, South Central China and Northwest China, which can provide reference for future air traffic control reform and development.
Adopting tree improvement into agroforestry system: a case study of introducing improved Acacia mangium in community-based forest in Pacitan, East Java
Authors: Nirsatmanto A , Kartikaningtyas D , Sunarti S , Setyaji T , Handayani B R , Surip  , Mangkuwibowo F
Published: April 2020

Tree improvement is a part of breeding development practices for producing genetically improved stock. Beyond the success on realizing the high productivity, products from tree improvement need some prerequisites for adopting in its operational, such as sitematching, fertilizer, spacing, monoculture and other silviculture practices, some of which are difficult to be fulfilled by the small grower under agroforestry system. As a result, the improved stocks are not commonly planted in small grower’s land. However, in supporting the development of productive agroforestry system, adopting tree improvement into agroforestry practices is necessary. This paper presents a case study of introducing the improved Acacia mangium in community-based forest in Pacitan, East Java. The site planting for this program was selected by considering the fact of the long history of traditional planting of Acacias in community-based forest in Pacitan accompanied with the increasing demand of the Acacias wood for home industries. The program was started at 2012 with the slogan of “planting and manage with your own available resources”. There are four main steps for achieving the goal of programs: 1) introducing improved stock through free distributing the seedling, 2) supervising and monitoring the growth and economic value, 3) establishing seed orchard, 4) autonomous on improved seed production for further replanting. After 6 years, this program revealed that while maintaining a high productivity and economic value, improved stock of A.mangium from tree improvement program could be successfully planted in smallgrower’s land under sustainable agroforestry practices with low cost of silviculture practices.
Land suitability for Persea americana as one of multi-purpose tree species at community agroforestry land in Langkat District North Sumatra Indonesia
Authors: Rahmawaty  , Frastika S. , Rauf A. , Batubara R.
Published: April 2020

Persea americana or commonly call as alpukat in Indonesia is one of Multy Purpose Tree Species (MPTS), found in agroforestry land in Langkat District, North Sumatra. This study aimed to map the distribution of land suitability for P. americana in Langkat District, North Sumatra, Indonesia. This research was conducted by survey method to collect soil samples based on land unit in the field. Land unit was obtained from overlay some maps (land use map, soil map and slope map) using Geographic Information System (GIS) in the research location. There were ten land units in the study area. Land suitability was evaluated based on the matching method. The GIS also was used to map the distribution of land suitability. The results showed that the actual land suitability classes for P. americana were moderately suitable (S2) and marginal suitable (S3). Moderately suitable with area 11.20 ha (0.1%) in Land Unit 8. This area has limiting factor in water avaibility (wa), root zone medium (rc), and erosion hazard (eh). Marginal suitable is located in several places, i.e. Land Unit 1, 4, 5, 6, 7, and 9 with wa was limiting factor (10,022.88 ha; 88.96%); Land Unit 2 and 10 with wa and rc were limiting factor (926.48 ha; 8.22%); and Land Unit 3 with wa, rc and eh were limiting factor (308.19 ha; 2.73%).
Morpho-anatomical adaptation of lesser yam (Dioscorea esculenta) on different planting pattern and relative light intensity in Java community forest
Authors: Sawitri  , Primananda E , Budiadi
Published: April 2020

Lesser yam (Dioscorea esculenta) is traditionally cultivated as a valuable crop species in a various planting pattern of teak-based agroforestry (AF) system in Watubonang village, Sukoharjo District, Central Java. Different planting pattern contributes to various light intensity which is associated with plant morphological and anatomical changes and directly affect to yam tuber production. Research site was selected by mean of purposive sampling method with three yam planting patterns, i.e. yam monoculture (Y), yam in trees along border (TAB) and yam in full teak trees (T-Y), in three replicates of 20 m x 20 m plots. In each plot, four subplots were established to investigate relative light intensity and take leaf samples. Changes in morphological and anatomical characteristics of yam to different planting pattern and relative light intensity (RLI) were studied, including leaf size, leaf color, tendril and internode length, chlorophyll content and stomatal density. The result showed that RLI were significantly different among planting pattern (Y: 78.66%, TAB: 66.94%, T-Y: 34.05%). Planting pattern and interaction between planting pattern and RLI significantly affected yam morphological and anatomical characteristics (of leaf size, tendril & internode length, and stomatal density) at P < 0.05. Leaf size, tendril and internode length increased with decreasing of RLI in TAB, but opposite adaptation was found in T-Y planting pattern. Higher RLI resulted in reductions of chlorophyll a and chlorophyll b content, and therefore increased of chlorophyll a:b ratio. Leaf color of yam grown under high RLI (Y) were light green, while those grown under shaded condition with relatively low light intensity (TAB, T-Y) were dark green that may related to the foliar chlorophyll content. Hence, a trend of decreasing stomatal density was found associated with lower RLI (Y: 35 stomatal/mm2, TAB: 25 stomatal/mm2, T-Y: 19 stomatal/mm2). Approximately 50-60% of RLI is suggested to be an optimum intensity for yam cultivation to support yam tuber production. Agroforestry practice by applying pruning and managing planting density are needed to reach the optimum light.
Silvicultural and economic aspects on combination of vegetatives (Falcataria moluccana-Sorghum bicolor L.) and terrace methods in the different slope lands
Authors: Karyati  , Santoso A E , Syafrudin M , Karmini
Published: April 2020

The vegetative and mechanic methods are soil and water conservation technology to prevent surface run off and soil erosion as well as protect soil nutrient. The study objectives were to know silvicultural and economic aspects on combination of vegetatives between Falcataria moluccana (sengon) and Sorghum bicolor L. (sorghum) and terrace methods in a steep slope (>25-45%) and a very steep slope (>45%) lands. The silvicultural parameters measured were healthy plant, survival rate, stem diameter, and height increments of sengon trees and sorghum’ yield. The economic aspect was analyzed to calculate the cost, revenue, and profit of the application of sorghum as intercropping plants in vegetative method. The healthy plant of sengon and sorghum reached 80-89% (good), survival rate of sengon reached 80-89% (good) and sorghum reached 90% (very good), stem diameter and height increments of sengon trees reached 2.90 cm year−1 and 2.06 m year−1, and the height increment of sorghum was 45.55 cm month−1 in the steep slope (>25-45%). In the very steep slope (>45%), healty plant of sengon and sorghum were 70-79% (moderate) and 80-89% (good), survival rate of sengon and sorghum was 80-89% (good), stem diameter and height increments of sengon were 2.43 cm year-1 and 1.73 m year−1, and height increment of sorghum was 33.05 cm month−1. Total cost, total revenue, and profit of the vegetative (sengon and sorghum) and terrace methods combination in the steep slope (>25-45%) were Rp9,181,128.47 ha−1cs−1; Rp1,800,000.00 ha−1 cs−1; and (-)Rp7,181,128.47 ha−1cs−1, respectively. In the steeper ground (>45%), this application expended total cost as much as Rp9,181,128.47 ha−1cs−1, total revenue as much as Rp650,000.00 ha−1cs−1, and profit as much as (-)Rp8,531,128.47 ha−1cs−1. Although sorghum was not profitable economically as intercropping plant in agroforestry system (sengon-sorghum) in different slope lands for short term, the method combination between vegetative (sengon-sorghum) and terrace techniques could useful to soil and water conservation as well as environmental aspect for long term.
Species test of Mulberry plants on agroforestry land for silk yarn quality improvement in Bali
Authors: Sasmita N , Purba J H , Komara L L , Yuniti I G A D
Published: April 2020

Mulberry plants are tested on agroforestry land because of its well adaptation. The agroforestry model is a combination of sengon (Falcataria moluccana) and mulberry (Morus sp.) plants. The selected mulberry plants consisted of three species, namely M. alba, M. cathayana and M. nigra. The study objective was to determine the best mulberry species leaves as silkworm feed to produce quality cocoons on agroforestry area in Bali. The test was carried out in a complete randomized design (CRD) with the species treatment of M. alba, M. cathayana and M. nigra. It consists of three replications each. Each replication consists of 100 silkworms. The variables observed in this study were cocoon quality and thread/fibber including the percentage of larvae which become a cocoon, the percentage of normal cocoon, cocoon weight, cocoon skin weight, ratio of cocoon skin and fiber length. The results showed that the maintenance rendement (%) was M. alba (70%), M. cathayana (62,0) and M. nigra (60,5), weight of cocoon (g), was M. alba (1,47), M. cathayana (1.53) and M. nigra (1.41), Weight of filaments (mg) namely M. alba (30,12), M. cathayana (25,35) and M. nigra (26,25 ), and the rolling strength of silk thread, namely M. alba (97.45), M. cathayana (74.11) and M. nigra (69.27). M. alba, M. nigra and M. cathayana mulberry leaf species grown from agroforestry patterns can be used to feed silkworms. The mulberry cropping pattern type both monoculture and agroforestry did not show a significant difference in the silkworm cocoons quality and quantity. The highest maintenance rendement is silkworm fed by M. alba, second is M. cathayana and third M. nigra. M. nigra and M. cathayana compared to M. alba did not show significant differences in cocoon weight, cocoon skin weight, percentage of filaments and rolling strength of silkyarn.
Development of cloud-based bioacoustics monitoring system for supporting Integrated Pest Management in agriculture production
Authors: Nugroho A P , Purba S , Pratomo Y B , Hadi S , Suputa  , Utami S S
Published: April 2020

Integrated Pest Management (IPM) is a conception or way of thinking about Management of Plant Pests with a multidisciplinary ecological approach to managing pest populations by utilizing a variety of compatible control tactics in a coordinating management unit. Acoustic signals produced by insects can be used as a source of information about their presence and behaviour. Problems encountered in observing acoustic signals produced by animals in the context of integrated pest control are supporting equipment factors that can facilitate data acquisition, data management, and species identification based on audio recordings (species identification). The objective of this study is to design microcomputer-based bioacoustics monitoring system that is integrated with the cloud. In more detail, the specific objectives are (1) Designing microcomputer-based bioacoustics monitoring system as a supporter of data acquisition systems with cloud integration features, (2) Testing the performance of a bioacoustics monitoring system for field observations. Bioacoustics monitoring system based on a microcomputer with cloud integration has been developed to support the implementation of integrated pest management. The developed system uses a raspberry pi as a central processing unit in local for data acquisition systems that are connected to the cloud using the Internet connection. As a result of the laboratory-scale test in indoor and outdoor setup, the system could record sample insect sound (Katydid and Cricket) clearly for both conditions, although noise from environment also appears in data analysis affecting the insect identification in future utilization.
Gall rust disease incidence of Falcata (Paraserianthes falcataria (L.) Nielsen) in Falcata – based agroforestry systems in Misamis Oriental, Philippines
Authors: Palma R A , Tiongco L E , Canencia O P , Boniao R D , Florida E J , Dagonio J Y
Published: April 2020

Falcata – based agroforestry systems in eastern part of Misamis Oriental is affected by gall rust disease caused by Uromycladium tepperianum (Sacc,) considered as one of the most destructive disease. The objectives of this study at Misamis Oriental, Northern Mindanao were to (i) determine the status of gall rust disease incidence in selected eastern municipalities and city of Northern Mindanao, and (ii) determine the factors and its relationship with gall rust disease. The sampling intensity was 10% or 1,000 m2 of one hectare at each site. Twenty temporary sample plots per municipalities and city were identified and assessed with a total of 140 plots. Each plot contained 15-70 trees for observation. Gall rust disease incidence per municipalities and city varies ranging from occasional to very common. Across site the incidence is considered common (25->50%). Elevation, spacing and age were associated with reduction or increase in gall rust disease incidence in these parts of Northern Mindanao.
Run off prediction by using small plots at teak forest, dry land and settlement areas in Pitu village, Ngawi, East Java
Authors: Kusumandari A , Pratiwi I , Widiasmoro S
Published: April 2020

Erosion is the process of soil movement from one place to another. The different amount of erosion that occurs in every land-use is caused by the difference of land cover in every land use. The purpose of this study is to find out the amount of erosion, the value of runoff and runoff coefficients, the correlation between rainfall and runoff, also the correlation between runoff and erosion which occurred in three different land use types. This research was conducted in Pitu Village on 3 different land uses, first in the teak forest land-use, second in yard land use, and third in the agriculture field land use. Small plots of 22 m × 4 m were applied to determine the erosion and the value of runoff. SeXI-FS software is used to describe the diagram profile of vegetation condition in each land use. The data were analyzed by using linier regression to determine the correlation between rainfall thickness and runoff, also the correlation between runoff and erosion using Sigma Plot software. The result shows that the largest runoff occured in settlement land (averaged: 95.96 mm) and the smallest runoff in dry land (11.85 mm in average). The largest runoff coefficient occurs in settlement land (averaged: 0.22) and the smallest runoff coefficient in dry land (averaged: 0.025). The runoff coefficient for each type of land use is included in the low category. Rainfall depth has a positive correlation with runoff. The greater the rainfall depth, the greater the runoff produced.
Communities conservation activities to support sustainable land use of upstream Merawu Watershed
Authors: Hobo K B R , Suryatmojo H , Ngadisih
Published: April 2020

Land use in the upstream Merawu watershed is dominant with agroforestry and intensive agriculture. Poor land management and conservation might lead to land degradation and affect the function of land use in the upstream area. This study aims to find out the community conservation activities which support and maintain the function of land use as a recharge area and protect the downstream. We used a qualitative method in the form of interviews at two locations representing dominant land use in the upstream Merawu watershed, agroforestry in Leksana Village, and intensive farming in Penanggungan Village. We analyzed the data descriptively, supported by field observation and literature studies. We found that the form of conservation activities and its triggers in land management were different. Leksana’s community tended to do the agroforestry system, combined with terracing, contour strip cropping, organic mulch, and organic fertilizer as their local wisdom to maintain the land function. Penanggungan community’s conservation activities were based on the crops they grow, mostly potato, that needed to be planted perpendicular to the slope, using plastic mulch and chemical substances. They believe that the agroforestry has a negative impact on their crops while crop rotation and manual plowing using hoe are their remaining conservation activities to maintain the land function. The results prove that Leksana’s community is still considering conservation activities in their land management while Penanggungan’s community is not, due to the crops’ needs and economic factors.
The application of numerical simulation coupled flow and geomechanics in the study of geology-engineering integration
Authors: Ma Junxiu , He Xiaodong , Yu Huiyong , Chen Ang , Yang Shengfeng , Li Yunzhe
Published: April 2020

The low-permeability reservoir is mainly featured by small reservoir pore, tight, fine throat, high filtration resistance, and low oil productivity. After several years of working to recover hydrocarbons from these reservoirs effectively, it has been proven that creating complex fracture networks by multi-stage fracturing is one of the most efficient ways to enhance production. However, several factors affect the development of the complex fracture networks, and the in-situ stress is the most significant one. Low in-situ stress anisotropy [1] increases the possibility of creating complex fracture networks with hydraulic fracturing. In order to compensate for the in-situ stress anisotropy, based on the application of a numerical model coupled flow and geomechanics, this research analyzes the variation of in-situ stress and suggests arranging a sequence of horizontal well deployment. In addition, the research predicts the dynamic productivity coupled flow and geomechanics. From the results, this research concludes the dynamic change regularity of in-situ stress and the impact of difference well deployment, which is beneficial to optimize horizontal well deployment and fracturing design [2].
Performance evaluation of a novel viscosity-reducing agent for heavy oil
Authors: Liu Guoliang , Li Xuening , Zhang Fusheng , Liao Gongqing , Li Yikun , Sun Jianghe , Zhu Zhuoyan
Published: April 2020

Heavy oil has high viscosity, high content of resins-asphaltenes and poor fluidity, which makes it difficult to produce. In the early research, a novel viscosity-reducing agent with high molecular weights and various active groups was synthesized in the laboratory. Ion composition analysis of wastewater and heavy oil viscosity test of Jincai 27 well were carried out. The emulsifying and viscosity reducing properties of a novel viscosity-reducing agent for heavy oil under low shear condition were evaluated by water content change of emulsion phase and viscosity reduction rate. The results showed that under 50 °C and low shear (10∼20s−1) condition, the viscosity-reducing agent solution had a fast emulsifying speed for the heavy oil. The O/W emulsion with good emulsion stability formed after about 60min shear. The viscosity reduction rate for the heavy oil was above 90%. The emulsion micrographs showed that the emulsion was highly dispersed and the particle size was uniform with diameter of 2 microns or even lower. The viscosity value of viscosity-reducing agent solution with concentration higher than 1200 mg/L could reach 25.0mPa.s under 8.0s−1 shear rate and 50°C, which indicated that it had a certain thickening property. Artificial core flooding experiments showed that viscosity-reducing agent flooding could increase heavy oil recovery by more than 10% compared with water flooding.
Characteristic analysis and prediction technology of cooling, heating and power load in energy internet town of Xiongan New Area
Authors: Hou Lei , Yang Bo , Jia Na , Wang Zichi , Zhang Zhengwen , Zhang Yajie
Published: April 2020

Xiongan New Area is another important new area after Shenzhen Special Economic Zone and Shanghai Pudong New Area. According to the development strategy of high-point positioning of the new area, providing safe, reliable, clean and economic modern energy system for Xiongan New Area is one of the important tasks in the construction of the new area. In the process of establishing and optimizing the energy system, reliable data of energy consumption and load characteristics should be obtained first. This paper analyses the types of buildings in the new area and the local climate and meteorological changes, and takes into account the energy consumption of various internal and external factors. Based on this, the different climate conditions of different buildings in a year are discussed. The load characteristics of thermal and cold power are analyzed. Finally, a prediction method of thermal and cold load data considering climate and meteorological information, typical structural parameters of buildings, internal and external disturbances is established.
Research and application of key commissioning technologies for new generation of 300Mvar large synchronous condenser
Authors: Li Ming , Zhao Binchao , Liu Yibin , Xing Haiwen , Zhang Ting , Gao Wenlong
Published: April 2020

As the new generation of 300 Mvar large synchronous condensers have gradually been produced and installed in China, research on the commissioning technologies before being formally put into operation is particularly important. This paper mainly takes the view of the difference between synchronous condenser and the traditional large generator especially in the following respects of startup mode, over-excitation performance, and grid-connection mode. The commissioning technologies of electrical system, oil system, chemical system and monitoring system are put forward in detail. Furthermore, innovative achievements such as the optimization design of protection configuration and hot water flow method for checking the water circuit within the stator winding, along with the new type of apparatus for magnetization test of stator core are present. The commissioning technologies have been applied in Yi’nan converter station, which all successfully went into pre-operation after the commissioning work been completed, contributing a lot to the security of regional power grid.
Iterative model coupled with experimental procedures to determine flow rate in a closed natural circulation circuit
Authors: Bello Solomon , Gao Puzhen , Bilal Ashhar , Ahmed Nisrene M , Lin Yuqi
Published: April 2020

A set of simplified iterative model coupled with experimental procedures has been derived to aid in computing the flow rate of a closed rectangular NC Circuit at low pressure/low power steady state condition. The approach involves partitioning the NC loop into different pressure loses segments depending on the associated factor, thereafter the various pressure drops in each segment is determined with applicable mathematical correlations. The iterative model allows for varying of the outlet temperature, at a predetermined Heating Power (Decay Heat) and inlet temperature such that the flow rate is determined when the pressure drops equals to the driving force

(

Δ

P

drive

=
Σ
Δ

P

loss

)

. The model was applied in computing the flow rate of the NC loop considered based on the assigned parameters with results validated with experimental data showing good agreement. Microsoft excel was employed in the computation procedures to allow for simplicity and easy comprehension.
Discussion on the measures of achieving the sub-wet bulb temperature by evaporative cooling
Authors: Bai Yanbin , Yang Lizhong , Zheng Song , Huang Xiang
Published: April 2020

On the basis of introducing the wet-bulb temperature which is lower than the outdoor air temperature and achieved by the indirect-direct evaporative cooling technology, this paper argues that the sub-wet bulb temperature can be used to characterize the air and water-out state parameters of the equipment, and the sub-wet bulb efficiency can be used to characterize the degree to which such equipment can go below the wet-bulb temperature. Moreover, this paper also introduces the typical equipment of China and foreign countries which uses indirect-direct evaporative cooling technology to achieve the sub-wet bulb temperature. The sub-wet bulb efficiency of the foreign indirect-direct evaporative cooling equipment is 106%. According to test results, the sub-wet bulb efficiency of the indirect-direct evaporative cooling air handling units in China is 117%; the sub-wet bulb efficiency of surface pre-cooling evaporative chillers is 115%, and the sub-wet bulb efficiency of tubular pre-cooling evaporative chillers is 120%. Therefore, the analysis results show that the sub-wet bulb temperature and sub-wet bulb efficiency can be used to directly characterize the air/water-out state parameters of such equipment.
Study on deacidification process of waste internal combustion engine oil under the action of ultrasound
Authors: Gong Jing
Published: April 2020

Internal combustion engine oil must be replaced periodically because it deteriorates during use, owing to the formation of oxidized species, particularly organic acids. The oil can be regenerated by removing the acids through alkali washing and neutralization. However the neutralization forms soaps that can cause significant emulsification that decrease the rate of acid removal. We have found that the washing process can be enhanced by using ultrasound, which produces strong shock waves and cavitation that increase the rates of diffusion and mass transfer, leading to an increased rate of deacidification. Our experiments show that a binary base composed of 58 wt% alum and 1.8 wt% diethylamine works well at a deacidification temperature of 50 °C, ultrasonic power of 800W, deacidification reaction time of 18 min. The extent of deacidification can be as high as 88% at 1.5 h.
Research on visualization technology for abrasion of flow guide device in denitrification system based on Tabakoff model
Authors: Ma Lin
Published: April 2020

In order to obtain the abrasion condition of the internal guide device of denitration system reactor intuitively, based on the particle missing model and takeoff wear model, the gas-solid two-phase flow field in SCR reactor is simulated by ANSYS-CFX calculation software, and the fly ash movement track and wear rate distribution of guide plate are visualized. The simulation results show that through the combination of particle missing model and Tabakoff wear model with CFX software, we can directly see the general wear distribution of the guide device in the flue. The wear rate distribution is mainly affected by the particle size of fly ash, and the wear rate value is mainly affected by the mass concentration. By verifying the field flow field test data and checking the wear and ash accumulation of the guide plate, the technical effectiveness is verified, which provides a technical means for the guide device to prevent wear and blockage.
The comparative analysis of two injection modes and recharge capacity estimation for a radial well in the loess area of China
Authors: Zhang Xuezhen , Huo Aidi , Wang Jucui
Published: April 2020

This study is focused on the theoretical substantiation and practical application of the radial well recharge. Two semi-empirical equations were derived for the estimation of the recharge capacity and clogging coefficient of the recharge well, respectively. Two injection modes were applied to analyze the relations between the recharge capacity, water level, and flow rate. Two methods were used to calculate and verify the recharge capacity and clogging coefficient, with a brief analysis of their variation laws. The recharge capacity of the radial well was found to increase with the injection flow, with the following gradual saturation during two injection stages. The recharge capacity increased with the recharge flow, while the clogging coefficient of the second stage was higher than that of the first stage, and exhibited a different variation pattern. The results obtained strongly indicate that the pumping and recharge are hydrological processes, which differ from each other by their physical essence. The available calculation methods based on the pumping theory were found to overestimate the recharge well flow by more than six times. The refined semi-empirical equation provides a more realistic estimation of the recharge capacity of radial wells.
Chainsaw location finding based on travelling of sound wave in air and ground
Authors: Jubjainai Phumpichet , Pathomwong Sittichai , Siripujaka Poom , Chiengmai Na , Chaiboot Anek , Wardkein Paramote
Published: April 2020

Deforestation is a major problem in the world because it affects to temperature and increasing carbon dioxide. In this research, it is therefore proposed that the sound signal inspection of chainsaw which take place from deforest activity and localize the position of deforesting by using the sound signal detection of chainsaw that travels in two mediums are in the air and soil and find the time difference which two waves in both medium travel to the observer or the detector. The correlation operation is used to determine the time difference to calculate the distance between the sound source and the observer and find the direction of the sound source by rotating the microphone to get the most magnitude of sound and take the direction and distance to specify the location of the loggers. Which the proposed system is low complexity and energy-saving and can move easily. From the system test, it was found that the accuracy was 95%.
Fault diagnosis of photovoltaic system based on machine learning model fusion
Authors: Guo Xingke , Na Zhixiong , Ma Dayan , Lu Yudong , Luo Xin
Published: April 2020

With the reduction of non-renewable resources, the energy issues become more and more important and urgent. Distributed photovoltaic power stations not only provides more energy with flexible deployment, but also proposes a possibility of how to fully use the solar energy with a better efficiency. Although a distributed photovoltaic power station has many advantages and great potential, it is not easy to be operated and maintained. In recent years, the applications of machine learning in multiple fields make it possible to do the fault diagnosis of photovoltaic systems more efficiently. This paper designs a full processing system to realize the function of real-time fault diagnosis specially for distributed photovoltaic power stations, which includes the data processing, an online system to give the result of real-time diagnosis, an offline system to retrain models, and a fusion model of several machine learning algorithms. The data processing and performances of different models in this problem are introduced in detail. The fusion model that proposed in this paper acts much better than single models. Hence, the fault diagnosis system could be used in the operation and maintenance of distributed power stations.
An energy management model for isolated microgrid community considering operation flexibility
Authors: Ren Zhichao , Wang Xi , Ye Qiang , Cheng Chao , Li Huaqiang , Zhang Zhiwen
Published: April 2020

The isolated microgrids adjacent to each other form an isolated microgrid community, which can realize optimal resource allocation among microgrids with different source-load characteristics through energy sharing, thereby improving the economical, reliability and renewable energy utilization of regional power system operation. Aiming at the energy management problem of the isolated microgrid community, based on the multi-agent system, a hierarchical energy management architecture of the isolated microgrid community was established. On this basis, the flexibility index is introduced to evaluate the impact of renewable energy output uncertainty on system operation. A multi-objective optimization energy management strategy as well as a community layer energy allocation strategy is constructed. The linearized model is solved by the tolerant lexicographic method. Finally, an isolated microgrid community consisting of four microgrids is taken as an example to verify the effectiveness of the proposed energy management strategy.
Study on sensitivity and selectivity of three-stage current protection in distribution network with distributed generation
Authors: Gong Jing
Published: April 2020

The connection of DG (Distributed Generation) changes the topology of distribution network, which will lead to the change of current detected by relay protection, and the sensitivity and scope of protection will be affected. On the basis of introducing the setting calculation principle of three-stage current protection in distribution network, taking a 10kV distribution network with DG as a model, the influence of DG capacity change on the selectivity and sensitivity of three-stage current protection is discussed in detail when short circuit occurs in different locations such as downstream, adjacent and upstream lines. The corresponding restrictive factors are analyzed and the influence degree of DG access on the original protection is given after comprehensive comparison. It is concluded that comparing different short circuit locations, DG has the most serious impact on the stage-I selectivity of downstream protection when the short circuit occurs at DG downstream line. The conclusions in this paper are of great value to ensure the reliability of power supply of distribution network when a large number of DGs are connected to the grid.
A DC fault identification scheme for multi-terminal VSC-LVDC system based on voltage of current-limiting reactor
Authors: Wang Panbao , Sun Hongmei , Hao Xin , Su Wei , Yuan Dong , Wang Wei , Xu Dianguo
Published: April 2020

The rapid and effective identification of DC faults is one of the key technologies for the development of multi-terminal DC (MTDC) system based on voltage source converter (VSC). The DC system fault current is characterized of high increasing speed and wide influence range. At present, the peak current and the rising speed of the fault current can be limited by current-limiting circuits, which are serially connected at both ends of the DC line. In this paper, the DC fault characteristics of a three-terminal DC system with DC line current-limiting reactors are analysed. On this basis, a fast identification method for DC faults in MTDC system according to the voltage across the line current-limiting reactor is proposed. The proposed scheme can quickly identify the fault location, the fault type and the fault pole. Finally, the effectiveness of the proposed fault detection scheme is verified by simulations. The simulation results show that the proposed method is still effective when the fault resistance and fault distance change, and is able to realize the rapid and accurate detection of DC faults.
Health evaluation of urban water supply pipe network using the Bayesian method based on triangular fuzzy number optimization
Authors: Ding Xiangyi , Liu Siran , Shi Xiaolin , Chu Junying , Guo Xinlei
Published: April 2020

With the rapid increase of urbanization level in China, the accidents related to urban water supply pipe network occurred frequently due to the impacts of pipeline aging, environmental change and human factors, thus the health evaluation of urban water supply network has become one of the hot topics in recent years. Related researches mostly refer to qualitative and static analysis, some quantitative studies consider the influence of only one aspect on the status of water supply pipe network such as hydraulic, water quality and static structure, and cannot objectively reflect the health status of pipe network due to neglecting or simplifying the influence of internal hydraulic condition on the health of the pipe network. Comprehensively considering the influencing factors and the hydraulic mechanism during the operation process of pipe network, this study constructs a health evaluation index system for the water supply pipe network, and introduces the triangular fuzzy number theory into the traditional Bayesian water supply network health status evaluation model taking the uncertainty of model structure and data into account. Through applying the method to Yunhe county of Zhejiang Province China, some suggestions for the optimization and transformation of the regional water supply network are proposed, which can provide a basis for ensuring the safety of regional water supply and scientifically determining the renewal sequence of the pipe network.
Differentiation of digestion method for heavy metals in river sediments based on organic matter gradients
Authors: Liu Jinbao , Shen Qiu , Wei Fang , Guo Zhenni , Tian Yingjie
Published: April 2020

Heavy metal detection in river sediments is critical in evaluating heavy metal pollution levels, risk and control in these matrices. Most of existing detection methods have the disadvantage of low recovery rate and high total acid consumption. Due to continuous accumulation of metal and relative high content of organics in river sediments, this paper focused on studying differentiated digestion method of heavy metals based on organics gradient grading. Surface river sediment samples were collected from 26 different rivers and lakes within the Qiantang River basin (e.g. Hangzhou and Jiaxing). Organic matter content in these samples were tested and these samples were divided into 8 groups according to content of organic matter. This was followed by testing the effects of hydrochloric acid, nitric acid and hydrofluoric acid on the digestion of heavy metals (Cu, Zn and Ni). The optimum digestion system of heavy metals in river sediments based on organic matter gradients was established. Results demonstrated that digestion system can achieve high recovery rate (90%∼110%) and an average dectection accuracy, while total acid consumption is about 10.54 mL, which is less than that of the Chinese standard digestion method (19mL). This means that the digestion system proposed in this paper is environmentally friendly.
Birds protection and safety research of transmission lines
Authors: Liu Hui , Zhou Chao , Shen Qinghe , Yao Jinxia , Liu Chuanbin , Qi Zhao
Published: April 2020

Bird related fault of transmission line has become the main factor of line trip. The rule on bird related fault of transmission line is shown in this paper which contains monthly distribution, monthly distribution, reasons of faults and the state of reclosure, the species of related birds, time and season of the faults, environment around the towers, type of towers and insulators and flashover and burns characteristics of the faults. With regard to problems of bird related faults, several anti-bird measures and its characteristics are studied. It is suggested that anti-bird devices should be installed above jumper wires to eliminate the blind area of bird repellent.
Groundwater assessment based on analytic hierarchy process and the normal cloud model in Weinan, China
Authors: Qu Wengang , Xu Panpan , Qian Hui , Zhang Qiying
Published: April 2020

Groundwater quality is facing a grim challenge due to the development of Weinan city. A multi-index comprehensive evaluation method—analytic hierarchy process and normal cloud model are proposed to evaluate the groundwater quality of Weinan city. Seven parameters including TH (total hardness), TDS (total dissolved solids), SO4
2-, Cl−, COD, NO2
−, Mn were selected to characterize the groundwater quality. The results show that the groundwater quality level of W6 and B557 are excellent water quality (I), H32, W15, W23, and W14 are good water quality (II), only B24 is medium or average water quality (III). Compared with other methods, the results obtained by the proposed method are in good agreement with the NI method but far from SFI method. This study confirms the suitability of the Analytic hierarchy process and Normal cloud model method in groundwater quality evaluation in Weinan city, and provides a reasonable basis for decision-makers of groundwater protection and utilization in Weinan city.
Trend and abrupt analysis of Dongting Lake water level and its driving forces using Mann-Kendall approach
Authors: Dai Lingquan , Liu Haibo , Li Wei , Tang Zhengyang
Published: April 2020

In order to quantitatively describe the evolution trend of Dongting Lake water level and its driving forces, the Mann-Kendall approach is used to determine the lake water level and its driving forces, including the discharge of the Yangtze River at Yichang hydrological station, three outlets, and four rivers. The results show that the annual runoff and the runoff from September to October of the Yangtze River, the annual runoff of the three outlets have a significant downward trend, especially after the impoundment of the large reservoirs on the middle and upper reaches of Yangtze River. The Yangtze River discharge has a sudden change during the impoundment period, while the annual runoff and the runoff from September to October of the four rivers showed an insignificant decrease trend. The lake water level at Chenglingji decreased during the impoundment period of the large reservoirs slowed down, especially in September and October, so we can see that the reservoir impoundment is an important factor that decreasing the water level of Dongting Lake.
A preliminary study on the relation between camphor wood volatile matters and corrosion of museum metallic objects
Authors: Shen Jingyi
Published: April 2020

Camphor wood is a traditional storage material used in Chinese museums for repelling insects and inhibiting moulds. Since camphor wood continuously emits volatile matters, it leads to potential risks to museum collections on the other hand. Oddy test was conducted in this study to evaluate the reliability level of four different camphor wood samples for museum use. The samples were put into water and the pH values were measured in order to learn the acidity of each sample preliminarily. Modern instrumental methods including gas chromatography – mass spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy, were employed to identify the volatile matters emitted by each sample and the corresponding corrosion products, respectively. The identification results were discussed together to infer possible corrosion mechanisms and evaluate the effects of aging time and species. The results showed that compared with the Cinnamomum camphora samples, the Cinnamomum glanduliferum sample led to higher risk to the metallic objects, while the reserve of acetic acid tended to decrease along with continuous aging of the Cinnamomum camphora sample but the risk did not decline significantly.
A study on drag reduction scheme of 200MW DACCU bag filter
Authors: Lyu Yu kun , Yang Jiaxi , Wang Jiawen
Published: April 2020

The DACCU bag filter is the main equipment of pollution control in power plant. The resistance is closely related to its structure. Based on the original structure size and field measured operation parameters of bag filter, the CFD was used for numerical simulation analysis to find out the area with the largest resistance in the original model, thereby meeting the actual demand of the overall resistance reduction and flue gas uniform distribution of the bag filter. Accordingly, three successive improvement schemes were designed from three aspects of flue gas inflow derection, flue gas distribution plate’s angle and the number of distribution plates. The numerical simulation method was used to optimize to the minimum resistance to ensure the safe and stable operation of the unit. It provides a reference for relevant engineering design.