bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis on Factors Influencing Sludge Composting
Authors: Gao Tong Yu , Dong Guo Ri , Wang Yu Heng , Wang Jian Dong
Published: December 2014

This paper makes a summary of factors influencing sludge composting on based on the reference to recent literature. As one of the effective ways to deal with the sludge resources, sludge composting has been studied by many scholars, with fruitful research results in aspects of condition optimization and process. The literature reveals that the main factors affecting the success of sludge composting include filler, moisture content, carbon and nitrogen ratio, thermophilic microbial agent, heavy metals and odor control.
The Impact of China’s Passenger Turnover Quantity on Farmer Income Increase
Authors: Zhang Cong
Published: December 2014

Based on the data of passenger turnover quantity, agriculture gross production, peasant workers’ salary and rural per capita net income from 1973 to 2013 of China, this paper empirically analyzed the impact of China’s passenger person-kilometers on rural per capita net income. By build Var model, Co-integration Rank Test and Granger Causality Tests, author illustrate the relation between passenger person-kilometers and rural per capita net income. The results show that there are one way lead relations and long-run equilibrium relationship between them. The increase of person-kilometers has positive influence on rural per capita net income. We can promote the farmers' income by strengthen the construction of rural roads and planning the road network more reasonable.
Optimization Model of Bus Station Based on the Largest System Benefit
Authors: Qian Jun , Jia Fu Qiang , Liu Yuan , Wei Bin
Published: December 2014

By applying time-value theory, this article establish a optimization model of bus station based on the largest system benefit.As the model works out, design algorithm of it by using dynamic programming theory. Meanwhile combine a instance to verify the model,the model has been proved to be brief and easy with combining physically more closely and supervising some real work preferably.
Transport Practices in Metropolitan District Development
Authors: Li Cong , Wang Xian Guang , Sun Xiao Nian
Published: December 2014

In the last few decades, metropolitan districts have played an increasingly importance role in process of urbanization. To support this trend, transport, as a fundamental and strategic industry sector, should promote the development of metropolitan districts. This paper studies transport practices in metropolitan district development from varied dimensions: transport concept, transport infrastructure, administrative organization, and transport service. Corresponding to these dimensions, the representative transport practices that are closely related to metropolitan districts are investigated, which include the concept of smart growth, the intense and complex transport corridor, the interregional plan organization, and the intermodal passenger transport. Finally, conclusions are drawn and further suggestions are suggested.
The Culture of Evaluation to Improve the Airport Competitiveness of the Metropolitan City of the Strait: Analysis of Alternative Scenarios of Connection
Authors: Della Spina Lucia , Scrivo Raffaele , Ventura Claudia , Viglianisi Angela
Published: December 2014

Questo articolo illustra una proposta metodologica e una applicazione combinata di metodo Delphi e un Hierarchy Process nalytic (AHP) . Sono strumenti a supporto delle decisioni - a causa, rispettivamente gli scenari avvicinano e Multicriter ho una decisione Analisi - e hanno lo scopo di affrontare i problemi e processi in cui le scelte hanno una natura complessa e un ambito strategico. Proponiamo un processo di valutazione combinata: Delphi- multicriterio - progettato per superare alcune debolezze degli approcci alla scenari e multi-criteri, mentre il consolidamento e la convalida dall'esperienza empirica e la letteratura. Particolare enfasi è posta sul nodo della partecipazione delle parti interessate nel processo decisionale cruciale, normalmente conferiti momento tecnico e gestito da analista-decisore. Per quanto riguarda l'area di riferimento, per il ragionamento teorico e la sua applicazione ad un caso concreto, ha sarà dato risalto al problema della scelta tra scenari alternativi che collegano il miglioramento dell'aeroporto della Città Metropolitana di (Italia) competitività della Stretto.
A New Method of the Touch/Leakage Protection without Dead-Zone Considering the Phase Characteristics
Authors: Yuan Zhi Jian
Published: December 2014

After investigating the residual current protection and its major deficiencies, it is found out that the touch/Leakage current could be separated from the total residual current by the current separation technology , which is based on the phase relationship between normal residual current and touch/leakage current. A novel leakage current protection principle without protection dead-zone is proposed .The proposed method, which is put into practice on DSP , proves to be accurate and feasible in digital simulations. Compared to the existing techniques based on the residual current amplitude or its variation,the proposed method can eliminate protection dead-zone effectively and improve the reliability of protection devices drastically.
Modal Parameter Identification of 500kV SF6 Current Transformer Based on Natural Excitation Method
Authors: Zhang Qian , Lu Zhi Cheng , Sun Yu Han , Zhong Min
Published: December 2014

In this paper the feasibility of natural excitation method which uses cross-correlation function instead of impulse response function of the response to identify the modal parameter of 500kV SF6 current transformer was discussed .Four different algorithms were used to extract the modal parameter of 500kV SF6 current transformer with the measured cross-correlation function obtained by natural excitation method. The results of modal parameter identification using natural excitation method and experimental modal analysis were compared in the experimental way.
Regulation Right Trading Considering DSM in Shanghai Power Grid
Authors: Liu Dun Nan , Zhao Yan , Li Lei , Liu Rui Zhi , Xu Yu Jie
Published: December 2014

With the implementation of energy-conservation power generation dispatching, power grid will lose some peak regulation capacity, and changes of load demand characteristic will further increase the difference between peak and valley load of power grid, especially in the Shanghai grid, primarily thermal power units. Its peak regulation capacity will be obviously insufficient, and the problem will become increasingly prominent. This presents a new topic for Shanghai power grid in the power generation market: Under the premise of meeting the customers’ need, how to provide a fair competitive environment that encourage power plants to participate in power peak regulation actively, and then lead the grid to safe, high quality and fairly competitive virtuous cycle.
A New Variant Harmony Search Algorithm with Random Mutation Strategy
Authors: Zhao Xiu Hong
Published: December 2014

Harmony search (HS) algorithm is a good meta-heuristic intelligent optimization method, which has been paid much attention recently. However, intelligent optimization methods are easily trapped into local optima, HS is no exception. In order to improve the performance of HS, a new variant of harmony search algorithm with random mutation strategy (HSRM) is proposed in this paper. The HSRM uses a random mutation strategy to replace the pitch adjusting operation, and dynamically adjust the key parameter pitch adjusting rate (PAR). Experiment results demonstrated that the proposed method is superior to the HS and recently developed variants (IHS, and GHS) and other meta-heuristic algorithm.
Crane Location Optimization Method for Substation Construction
Authors: Li Wen Jiang , Leng Zhou , Jia Chuan Guo , Lu Peng , Liu Yan Xing
Published: December 2014

Generally, a substation involves a great many components, i.e., electrical equipment and precast elements, of large dimension and weight. Its lift planning has a major impact on construction sequence, scheduling, budgeting and safety. An optimization method for the scenario of single-cane-multiple-lifts is presented, mainly considering the objective to minimize the number of crane relocations. The method starts with identifying possible location zones by means of the constrained work envelope strategy and the grid traversal algorithm. Later, it adopts the multiple-target integer programming method to minimize the number of location zones that can lift all components, and then to maximize the total number of components that the available zones can lift including duplication. For each optimized zones, it checks the optimal location by means of the traversal algorithm, considering the minimum of the sum of the weighted load factors for all components. To avoid spatial interference, an automatic simulation is done by means of which any missing interference can be checked manually. Lastly, a case study is done to demonstrate the validity and practicality performance of the method.
Mine 3D Geological Interface Modeling by NURBS Technology
Authors: Yang Zhen Xing , Zhou Jian Jun
Published: December 2014

It is imperative for 3D modeling of mining or underground engineering to precisely and efficiently describe various interfaces, which is also the precondition for 3D visualization of underground engineering. NURBS (Non-Uniform Rational B-Splines) curve and surface technology are introduced in the paper. With help of analyzing 3D geologic structure of Laohutai mining area and comprehensive treatment of surfaces of tunnels and geologic structures. 3D geological surfaces of mining area are built which is the base of building complex 3D geologic modeling.
3-D Geological Modeling of Complicated Underground Engineering by B-Rep and NURBS
Authors: Zhou Jian Jun , Yang Zhen Xing
Published: December 2014

In order to obtain 3-D geological modeling and visualization of complicated underground engineering, a 3-D geological visualization modeling based on data structures of B-Rep and NURBS is proposed. Through comprehensive analysis of common data structure for describing the space topology in the field of computer graphics, rapid establishment of accurate topological relation of 3-D geological models for underground engineering in complicated geological conditions and cavern groups is achieved. And the high-quality geometrical data and topological relation information for the geological visualization of slope engineering are provided. By taking a large coal mine as an example, the 3-D visualization model with many functional applications based on geological information is given, which provides a basic platform for the realization of 3-D digital management.
Experiment on Incipient Motion of Different Clay Content Sediment
Authors: Xiao Hui , Li Yan
Published: December 2014

Based on 8 group sediment samples of the median diameter between 0.0084 mm ~ 0.067 mm and the clay content between 1% ~ 40%, carried out the incipient condition test under current action and wave action respectively in laboratory, the results show that: sediment incipient condition increases with decreasing the median diameter and increasing the clay content; while the clay content is more than 10%, the incipient condition increases significantly with increasing the compactness of bottom sediment; the results can provide the reference for the engineering construction.
Load Effects Analysis of High-Pile Pier Skid-Way Quay while Offshore Platform Loaded to Barge Whose Deck Elevation Adjusted by Aided Jacks
Authors: Sun Bai Shun , Liu Hong Biao
Published: December 2014

The vertical bearing capacity calculation and security evaluation methods of high-pile pier skid-way quay while large offshore platform moving to barge whose deck elevation adjusted by aided jacks are researched by the theoretic analysis and numerical calculation method. Based on the study, the load effects of 6000ton skid-way quay are acquired under the offshore platform weight and jacks load caused in the process of large platform moving to the barge whose deck elevation adjusted by aided jacks, the security of skid-way is assessed, and the security measures of skid-way structure which should be taken during moving platform are proposed. The analysis of simulation results shows that the bearing capacity of skid-way in vertical meets the requirements of design under the jacks load and platform weight by using uniform pressure to compute. The 6000ton skid-way quay is secure while large offshore platform loaded to barge whose deck elevation adjusted by aided jacks. The conclusions above can provide the experience for the security evaluation of high-pile pier skid-way structure and the optimization of procedure to load the large offshore platform on barge whose deck elevation adjusted by aided jacks.
Research on the Stress-Strain Law of Abutment Approach Embankment Filled with Liquid Fly Ash
Authors: Li Hong Liang , Jin Can Zhang , Yang Chun Feng , Gao Heng Nan
Published: December 2014

Because of the narrow condition of bridge approach embankment, the large compacting machines can not use in the embankment construction. The differential settlement between abutment and approach embankment was easy to produce. Coupled with the the structural differences of the abutment and embankment, how to ensure abutment stable and prevent bridge head bump has been an engineering roadblock in the abutment approach embankment filling engineering. The key factor to solve the problem of the roadblock is reducing the horizontal thrust of embankment on abutment and the difference in settlement between road and bridge. Test results showed that liquid fly ash is a new lightweight value material of self-compacting, which has higher strength, stiffness and smaller density. Using liquid fly ash as the bridge-approach embankment filling material can effectively reduce the horizontal thrust of embankment on abutment and decrease its own settlement deformation. ANSYS computational analysis showed that when we use liquid fly ash filling the bridge approach embankment, the horizontal thrust of the same position will increase with the increase of the filling height, and the value is lesser than the horizontal thrust of soil filling subgrade. Pavement settlement increases with the filling height increasing, but it is significantly less than the general soil filling subgrade.
Sea Cliff Stability in Tibau do Sul, Brazil
Authors: dos Santos Jr. Olavo Francisco , de Freitas Neto Osvaldo , Severo Ricardo N.F. , Scudelari Ada
Published: December 2014

The city of Tibau do Sul, a popular tourist destination in Rio Grande do Norte state, is famous for its sea cliffs, which reach a maximum height of 50m. However, mass movements are causing them to retreat. The aim of this paper is to study mass movements and their causes on the coast of Tibau do Sul, in order to better understand cliff dynamics and assess the constructive potential of the surrounding land. Field work was undertaken to characterize the area and analyze slope stability using the Hoek and Bray method [1]. The effects of height, inclination and ground cohesion were analyzed for stability.
Study Impact on Water and Sediment from Nansha Harbor
Authors: He Jie , Chen Jing
Published: December 2014

The construction of a series of docks in Nansha harbor would lead to the increase of the sediment silting in harbor basin, and the forecast for the amount of the sediment silting is a necessary work to do. The numerical model through verification shows that the source of suspended sediment is from the south of the harbor area, the thickness of sediment silting along the harbor has the characteristic ‘low in the north and high in the south’, and the sediment silting in phase IandII basin will be declined after construction. Those characteristics will be a good suggestion for us to design the planned harbor.
The Calculation on Discharge Capacity of the Porous Pipe
Authors: Jin Jin , Liu Huan Fang , Du Tao
Published: December 2014

The porous discharge flow tube has been widely used in agriculture, water supply and drainage, ventilation, chemical and other fields. Flow characteristics directly affect the flow uniformity of the porous tube, thereby affecting the efficient use of it. The theoretical analysis and experimental study on the capacity of the porous tube’s discharge (flux of water) have the important project value and theoretical significance. In this paper,the total flow calculation formula is derived by the knowledge of hydraulics, the relation of discharge discount rate is calculated through dimensional analysis and the average single hole discharge formula is established based on some experimental data. The results of the test data and engineering data showed that the formula results and the test results are quite identical.
Analysis of the Surface Structure Variability of Capital Airport Road
Authors: An Yan Qing , Liu Wei Hui , Yang Qiang
Published: December 2014

Because the airport road surface is directly under the aircraft repeated taking off and landing, the airport road surface should have a good overall structure, high strength, good performance of anti overload fatigue. Under the long action of aircraft, road surface has been damaged. coupled with rising large wide body aircraft and air traffic, airport of old pavement disease gradually increased, the use of a sharp decline in performance, airport pavement performance directly affects the safty of the plane running. Through the research of the capital airport runway to central structure parameters, pavement on the basis of the findings, the distribution of the pavement structure parameters variability is analyzed, and the pavement damage condition of objective evaluation; combined with the drilling core sample laboratory test data and aviation business volume data, scientifically on the pavement damage character analysis, and provides a reference for future similar engineering treatment.
Analysis on the Effect of Expressway Horizontal Curve Radius on the Driver's Visual Features
Authors: Xiao Tian , Sun Ji Shu , Geng Xiao Ting , Jin Can Zhang
Published: December 2014

The driver's visual features is crucial for traffic safety. The horizontal curve radius has a significant effect on the driver's visual features when driving on the expressway curve sections, which include the eye gazing scope, eyeball moving speed and so on. Through the measured data of the eye tracker system, the relationships between the horizontal curve radius and operating speed,eye gazing scope or eyeball moving speed and other traffic and visual features were studied systematically. The influence law of horizontal curve radius on the driver's visual features and their calculation formula was obtained. These achievements were beneficial to determine the expressway horizental alignment that ensure driver's visual comfort and improve the comfort and safety of highway driving. Meanwhile it can provide us some supplementary and reference for the specification.
Construction Technology Research Expressway Soft Long Pile Lakes
Authors: He Mei Yan
Published: December 2014

Currently, bored pile been widely applied in the current road and bridge construction, But its construction technology in complex geological case is still not perfect. In view of this, this paper carried out a high-speed Lakes viaduct extraordinary pile foundation construction project. For the analysis of the technical difficulties in the construction process, explore get the corresponding key construction technology, and it relates to the accident and its approach are summarized, study drew long pile construction technology Lakes geological conditions under soft silt and clay, solve the long holes bored pile into the lake silt soft clay under geological conditions, verticality control and other technical problems, can provide reference for similar projects.
Reinforcement of Railway Switch with Longitudinal and Cross Beams
Authors: Liu Yu Sheng , Gao Hui
Published: December 2014

Reinforcement with longitudinal and cross beams is one of the frequently employed methods for reinforcement of railway. Regarding the special case of box culvert going rightly under the railway switch, this paper conducts feasibility analysis of the reinforcement method by numerical simulation with the assistance of finite element software. It offers important theoretical guidance for similar railway switch reinforcement projects.
Plate Load Test Applied to Detect Bearing Capacity of the Miscellaneous Fill Subgrade Reinforced by the Dynamic Compaction
Authors: Zheng Ming , Yang Jian Ming , Li Zi Long , Zhou Ming Hui
Published: December 2014

In view of the dynamic compaction method to reinforce the miscellaneous fill subgrade plate load test, the consolidation of the miscellaneous fill characteristic value of subgrade bearing capacity is between 160~326 KPa, and foundation coefficient K30 value is between 122~229 MPa/m. The degree of miscellaneous fill reinforced roadbed compaction is located in between 94.8%~ 99.0%,which is detected through the sand filling method . Plate load test can be used as one of the evaluation index of highway roadbed performance.
Sustainability Assessment on a Case Study of Using In Situ Cold Recycling Materials in Road Maintenance
Authors: Zhu Bao Lin , Tian Miao Miao , Cao Yan Hua
Published: December 2014

The case ‘Using in situ cold recycling for carriageways in an urban environment within the North of Essex’ was chosen as a sustainability assessment example in this paper. The purpose of this paper is to assess the sustainability of the case above, to specific its impacts on environmental, economic and social aspects, and obtain a result of the assessment. Firstly the background of the case will be introduced, and the impacts and assessment will then be discussed. The result of the assessment will also be presented in the final part.
The Dynamic Response of Large Longitudinal Slope of Asphalt Road Pavement under Heavy Impulsive Load
Authors: Li Yan Chun , Xin Yuan Yuan
Published: December 2014

In order to conduct a further investigation of the causes of damages in large longitudinal slope of asphalt road pavement under actual heavy load, a three-dimensional finite element model was established by ANSYS finite element software. Through applying impulsive load in this model, the variation of the strains of large longitudinal slope of asphalt road pavement under different conditions was obtained and the influence of gradient on the dynamic response of large longitudinal slope of asphalt road pavement was analyzed. The results show that the strains of large longitudinal slope of asphalt road pavement increased with the increase of load times. Flexure tensile strain and shear strain were similitude with the change tendency of the increase of overloading rate but the data increased significantly. The transversal shear strain increased with the increase of gradient.
Analysis for Influence of Structural System on Nonlinear Seismic Response of Cable-Stayed Bridge
Authors: Chen Bai Ben , Feng Zhong Ren , Wang Xiong Jiang
Published: December 2014

For different structural system of cable-stayed bridge, the dynamic characteristics have obvious difference under seismic load. Dynamic time-history analysis of earthquake was applied, and the EI Centero seismic wave with modified peak acceleration was chose as the earthquake acceleration time-history input. As Jiangsu Siyang special-shaped single tower cable-stayed bridge for engineering background, considering geometric nonlinear of structure, the differences of dynamic characteristics of cable-stayed bridge structures were gained under two different situations. The single longitudinal seismic ground motion was chose under the first situation, while the longitudinal, lateral, and vertical seismic ground motion are introduced. For floating system, the displacements are the largest and the inner forces are the smallest. For rigid frame system, the displacements are the smallest and the inner forces are the largest. The others are not much difference. Comprehensively, semi-floating system has better performance under seismic load.
Construction Monitoring Technology for Large-Span PC Continuous Box-Girder Bridge with Corrugated Steel Webs
Authors: Liu Zhao Cai , Hou Lin Jie , Chang Can Hua , Zhou Chong Hui , Wan Shui
Published: December 2014

Through the construction monitoring of a large-span bridge which is a single box single room PC continuous box-girder bridge with corrugated steel webs, suitable methods are summed up. Finite element simulation was combined with field measurements data to calculate the model elevation of construction. By adjusting and control the model elevation, the linear shape of the bridge met the design requirements. By collecting strain data of the key sections of the bridge, abnormalities that may exist could be detected timely so that early warning could be made and construction safety and quality could be ensured.
Sensitivity Analysis on the Influence Factors of Mid-Span Deflection for Continuous Rigid Frame Bridge
Authors: Jiang Tian Hua , Ai Li , Chen Lei , Xu Hong
Published: December 2014

The common problem of continuous rigid frame bridge is excessive mid-span deflection. The three factors of excessive deflection including vehicle loads, structural rigidity and prestressed loss are discussed on the case of a three spans continuous rigid frame bridge. Midas Civil is applied to analyze the sensitivity of mid-span deflection for these factors. The results indicate that the deflection is increasing with the increase of vehicle loads or the decrease of structural rigidity or the increase of prestressed loss. Furthermore, mid-span deflection is the most sensitive to the change of prestressed loss.
Technology of Precasting and Installing for Integral Segment in Composite Girder Cable-Stayed Bridge
Authors: Du Song , You Xin Peng , Peng Cheng Ming
Published: December 2014

The main bridge of Quanzhou Bay Sea-Crossing Bridge is a composite girder cable-stayed bridge with span arrangement (70+130+400+130+70) m and with double pylongs,separated decks.It’s the first time to using the dry joints assembly in composite girder cable-stayed bridge,the technology of precasting and installing for integral segment is introduced.
Temperature Field and Thermal Stresses due to Solar Radiation in Concrete Water-Conveying Box Bridge
Authors: Mao Song He , Liu Fu Sheng , Wang Xin Yuan
Published: December 2014

The reasons that the differences in temperature distributing and thermal stresses are produced in water conveying Box Bridge under solar radiation are analyzed in this paper. By FEM software ANSYS, temperature field and thermal stresses are simulated. Results indicate that temperature distribution in water-conveying concrete box bridge due to solar radiation is very complex. Temperature changes in the top plate are the most severe, followed by web-plate, with the bottom slab minimum. The actual temperature distribution can be approximately considered as conic curve. Under solar radiation considerable thermal stresses are produced in concrete box bridge both along the longitudinal and transverse direction and their value exceed tensile strength of the concrete. Therefore, thermal stresses under solar radiation must be considered in the design of water-conveying box bridge and temperature reinforcing bars should be appropriately added to the structure.
Cellulolytic Enzyme Lignin Efficiently Blended with Polycaprolactone: Thermal, Mechanical Properties and Morphological Evaluation
Authors: Ouyang Wen Zhu , Huang Yong
Published: December 2014

In this study, cellulolytic enzyme lignin (CEL) was blended with polycaprolactone (PCL) by twin-screw extrusion and injection molding. The thermal, mechanical properties and the morphology of the PCL/CEL blends were investigated as a function of CEL content. The results showed that the CEL in the blends acting as nucleus accelerated the crystallization of PCL when CEL was not more than 10 wt%, but retarded PCL to crystallize with more CEL addition. Thermogravimetry analysis (TGA) revealed that the thermal stability of the PCL/CEL blends was almost unaffected by increasing CEL content. Mechanical test showed that, although the elongation at break and the impact strength were decreased, the strength and the modulus of the PCL/CEL blends were significantly higher than those of the neat PCL. Scanning electron microscopy (SEM) observations indicated that the CEL and the PCL were in good miscibility and there was a good adhesion at the interface of the CEL filler and the PCL matrix, suggesting that CEL could be potential filler used in PCL-based materials to reduce the cost of the friendly material, whereas increased its strength and modulus.
Electromagnetic Parameters Extraction of Electronic Current Transformer Based on Finite Element Modeling
Authors: Liang Xiao Bin , Tang Fan , Wu Jie , Zhen Wei
Published: December 2014

Electronic current transformer is one of the key equipment of intelligent substation and has a direct impact to the correct operation of relay protection devices. In order to accurately establish the dynamic response model of electronic current transformer, it is needed to extract electromagnetic parameters of Rogowski coil, which is the electromagnetic coupling part of electronic current transformer. This paper builds the electromagnetic parameters model and extracts the electromagnetic distribution parameters of Rogowski coil based on the finite element method, then we use the equivalent method to calculate the lumped electromagnetic parameter. At last, comparing with the experimental results, a good accuracy of the simulation results based on finite element method is presented.
Effects of Silage Additives on Biogas Production of Hybrid Penisetum
Authors: Xu Ran , Zhang Bao Yi , Yang Fu Yu
Published: December 2014

This study investigated the effects of silage additives on the anaerobic digestion performance of hybrid penisetum to produce methane. Specifically, we evaluated the effects of adding lactic acid bacteria (0, 1.0×105, 1.5×105, 2.0×105 cfu.g-1) and cellulase (0, 0.01, 0.02, 0.03 g.t-1) during ensilage for 45 days on biogas production of hybrid penisetum. The silage additives lactic acid bacteria (1.0×105cfu.g-1, 2.0×105cfu.g-1) and cellulase (0.03g.t-1) had a positive effect on the anaerobic fermentation performance of hybrid penisetum silage. The hybrid penisetum amended with 0.03 g.t-1 of cellulase showed the best biochemical methane potentials, with a methane yield of 218.15lN kg-1 ODMadded. The results of this study clearly demonstrate that type and concentration of additives influence biogas production by silage.
Characteristics Simulation of Ultra-High Frequency Electromagnetic Wave Excited by Equivalent Partical Discharge Mathematical Model in GIS
Authors: Xu Guang Ke , Zhang Wei Wei , Zhu Zhen Hua , Wang Nan , Zhao Fu Qiang
Published: December 2014

UHF electromagnetic waves radiated by PD in GIS can range from several hundreds of MHz to several GHz. FDTD method is usually used to simulate the characteristics of the UHF electromagnetic waves. Compared with the traditional ideal Gaussian pulses in simulation, one equivalent PD mathematical model based on the actual measure PD sources was considered to simulate the propagation characteristics. Time domain and frequency domain spectrum of signals excited by the two PD sources were studied to analyze the propagation characteristics. It can draw the conclusions that each insulator detect leads to each electromagnetic and its time domain and frequency domain spectrum. So it is recommended to use equivalent PD mathematical model to simulator the propagation characteristics.
Problem Analysis and Solutions in Transformer Field Verification
Authors: Wang Jin Liang , Xu Jia Heng , Jing Hui , Yuan Wang
Published: December 2014

Many error abnormities and verification difficulties appear in high voltage transformer field error tests. Field verification is with site and duration limit, so it is important to timely solve problems and complete tests. Field practical problems and solutions are expounded through technical analysis for technicians in the presented work.
Calculation of Electric Field under Overhead Lines with a Human Body Existing
Authors: Liang Zhen Guang , Li Can , Jiang Yu Ze
Published: December 2014

In the paper, electric field under overhead lines with human body existing is studied. The mixed method coupling finite element method with charge simulation method is constructed. Linkage of the finite element method domain and the charge simulation method domain is done by use of surface charge at interface. A simplified model with basic figure of human body is used. Calculation results show that human body has distortion effect on electric field nearby. Electric field at region very close to human body is greatly enhanced, while there’s little influence at region far away from the body. Head and upper side of human body play main roles of induction.
Static Characteristics Analysis for Induction Motors
Authors: Wu Ying Jun
Published: December 2014

This paper analyzes the static characteristics of induction motor. The models, as well as typical parameters, of induction motors for stability analysis are introduced. The slip-voltage curve, active power-voltage curve, and reactive power-voltage curve are obtained for analyzing possible operating states. According to the number and the stability of operating states, induction motors are classified to three kinds.
A Complete Decoupling PI Control of UPQC in α-β Coordinate System
Authors: Luo Zhi Qun , Han Wei We , Wan Jian Ru , Huang Shao Lun
Published: December 2014

Aiming at the existing strong coupling problem of UPQC model in synchronous rotating coordinate system, in order to realize the control process easily and accomplish the complete decoupling, two-phase coordinate system α-β was introduced to the complete decoupling PI control of voltage and current compensation unit. According to the corresponding mathematical model, the topology map of voltage and current compensation unit was gained. Direct single closed-loop control method was used, meantime, parameter was set and the structure chart of PI control unit was designed. Finally, the effectiveness and feasibility of the control method is proved by Matlab/Smulink simulation and hardware experiment.
Analysis of PCC Point Harmonics Caused by Nonlinearities of Grid-Tied PV Inverters
Authors: Zhao Yong , Yang Zi Long , Cao Du Feng , Wang Yi Bo , Xu Hong Hua
Published: December 2014

Renewable energy are usually connected to the power grid through an inverter. As the penetration level of such inverter-based distribution generation resources increases, PCC point harmonics become an important concern for grid stability and power quality. In this paper, the PCC-point harmonics in a parallel-inverter-based photovoltaic station were measured and some significant characteristics of such harmonics were presented. These harmonics are stationary; the voltage and current waveforms are lower frequency, power correlation and inter-harmonic. And these harmonics are 3-phase symmetric and contain 3rd and 6th harmonic components. The transitions of the PCC harmonic occurrence and vanishing are instantaneous. The analysis indicates that the PCC harmonics are not produced by the resonances related to the linearities of PV inverters but the inverter nonlinearities are the primary reasons. The strategy to eliminate the PCC point harmonics are proposed in this study.
Harmonic Characteristic Analysis of Five-Phase Space Vector PWM
Authors: Yu Fei , Xiang Dong
Published: December 2014

Pulse modulation width (PWM) of multi-phase inverter is the key technologies of ships electrical propulsion. In this paper, theories and realization of space vector PWM (SVPWM) for five-phase inverter is analyzed. The proposed SVPWM adopts two adjacent large voltage vectors to composite the reference voltage vector and this method have advantages of easy to realize. Theoretical waveform and harmonics of five-phase inverter output voltages under the proposed control method are deduced. The analysis shows that there are very large third harmonics in the inverter output voltages and currents. The total harmonic distortion (THD) is large also, and changes small with the modulation index. Simulation and experiments certify the conclusions.
Selective Depolymerization of Sulfuric Acid Pretreated Wheat Stalk under Microwave-Irradiation
Authors: Fang Jun Ji , Zhao Wei , Zhao Chen , Zhou Kai Xuan , Lei Qiang , Zhao Jing , Ren Ya Ping , Chen Shang Long , Liu Dan , Sheng Chen
Published: December 2014

The optimum conditions for selective depolymerization of wheat stalk under microwave-irradiation were determined by orthogonal experiments. Sulfuric acid was used as pretreated reagent. The liquid product (bio-oil) was examined by the gas chromatography/ mass spectrometry (GC/MS). The analysis of GC/MS of bio-oil indicated that furfural and butyrolactone were the main components, whose relative contents were 60.9% and 45.8% under its optimum conditions, respectively.
Torrefaction of Biomass: Effect of Temperature on the Properties of Liquid and Gaseous Products
Authors: Chen Deng Yu , Li Qian , Chen Yong , Sun Yan , Sun Xiu Ling
Published: December 2014

The torrefaction of rice husk was performed in a laboratory-scale torrefaction reactor at different temperatures (200, 230, 260, and 290 °C) for 30 min. It was found that the decomposition of hemicellulose was the direct reason for changes in the fuel properties of solid products after torrefaction. As the torrefaction temperature rose from 200 °C to 290 °C, the yield of torrefied rice husk decreased gradually from 97.47% to 67.03%, whereas the yields of liquid and noncondensable gas products increased from 2.01% to 15.67% and from 0.52% to 17.30%, respectively. Liquid products contained water and a small amount of acetic acids. CO2 and CO were the main gas products of rice husk torrefaction.
Smart Grid Control Technology of Multi Diesel Generator Set
Authors: You Wei , Wu Lian Hua , Yuan Yin Nan , Xi Guan Nan
Published: December 2014

In this paper, the application status of diesel generator set and the purpose and advantages and disadvantages of its parallel operation are summarized in brief. Grid connected operation of multi diesel generator are analyzed mainly. The necessary conditions of grid connected operation, the safety and special protect environment of grid operation, as well as the foreign and domestic development status of grid connected control technology are presented. Finally the development direction of grid diesel generator is pointed out, and the concept of smart grid is proposed.
Model Research on the Whole Industry Chain Value Analysis of Strong and Smart Grid
Authors: Zou Yi , Xu Xiao Hu , Wang Yang , He Bo , Huang Han
Published: December 2014

The smart grid has important strategic significance to lead the development of electric power industry upgrading and enhance the comprehensive benefits on economy, society and environment. Started from power generation, transmission, transformation, distribution and utilization five links of strong and smart grid, combined with the practical situation of China's electrical power system, in line with the value creation paths of demonstration projects in different links, this paper put forward the comprehensive benefit research framework of whole industry chain of strong and smart grid, and the general model for different value of whole industry chain. This paper selected two demonstration projects, “Large-scale clean energy grid connection” and “intelligent electric vehicle power charging and transportation network”, for applied analysis; further the inner logic relationship of value creation was expounded; finally the expectation on further application of the model was explained.
The Analysis of Micro-Grid Investment Income for Different Operating Modes
Authors: Yang Wen , Zhou Jian Hua , Zhang Xiao Yan , Lv Zhen Hua , Wang Ming Yao
Published: December 2014

Micro-grid gives full play to the advantages of distributed power supply by low pollution and flexible power supply form. Micro-grid has good economic benefits and social environmental benefits. Core technology of Micro-grid, policy support and grid-connected mechanism are problems encountered in Micro-grid construction and operation. Based on the analysis of development situation on the Micro-grid operation, this paper classifies the Micro-grid investors. According to the main purpose of different investors, this paper analyzes the cost structure and income structure of Micro-grid operation. And on this basis this paper proposed the corresponding optimal objective function under different Micro-grid operation modes.
Research of Loss Reduction Efficiency Based on DEA
Authors: He Xing Qi , Xian Qi Jun , Yan Ping
Published: December 2014

An evaluation system of loss reduction efficiency was established for power supply companies by using data envelopment analysis methods,and the empirical demonstration research was conducted for loss reduction efficiency of power supply companies in Sichuan.The evaluation results indicate that Institutional reform, grid construction and informationization promote the loss reduction efficiency of the power supply companies in Sichuan. However, due to the development foundation is weak, the scale efficiency is a key factor that restricts the loss reduction efficiency of the power supply companies in Sichuan, therefore, the investment must be increasing in order to improve the overall efficiency work of the power supply companies.
Effect of Carbon Sources and Fe3+ on the Growth and Lipid Accumulation of Monoraphidium sp. FXY-10 under Mixotrophic Culture Condition
Authors: Jiangwang Hao Miao , Huang Li , Yu Xu Ya
Published: December 2014

Effects of different carbon source and Fe3+ for the growth and lipid accumulation of Monoraphidium sp. FXY-10 cultured mixotrophically was studied in our present work. The final cell density was reached to 2.626 g L-1 when glucose was the only carbon source, which is 1.43-fold to sodium acetate (1.834 g L-1), far higher than sucrose (0.251 g L-1) and xylitol (0.471 g L-1), but barely grow in other culture condition. Additionally, the highest algae lipid productivity (77.45 mg L-1 d-1) was obtained in 10 g L-1 glucose group, which indicated that glucose was the optimal carbon source for growth and lipid accumulation of Monoraphidium sp. FXY-10. Nevertheless, Monoraphidium sp. FXY-10 was grew slowly in BG-11 culture medium with the absence of Fe3+. The biomass was achieved at the top with 50μM Fe3+ added. With the increase of Fe3+ concentration, it showed no variation in the growth of microalgae. The highest biomass productivity (209.87 mg L-1 d-1) was reached when the Fe3+ concentration was at 150μM while highest lipid productivity (94.05 mg L-1 d-1) reached at 50μM, which indicated that Fe3+ was one of the most indispensable trace elements for the growth and lipid accumulation of Monoraphidium sp. FXY-10.
Research on Coordinated Charging Strategy for Electric Bus Battery Swapping Stations
Authors: Su Su , Jiang Xiao Chao , Jiang Jiu Chun , Wang Wei , Huang Mei , Agelidis Vassilios G.
Published: December 2014

As a new type of transport, electric vehicles are becoming an important way to implement the energy and sustainable development of the city. Aiming at the Battery Swapping Stations (BSS) for electric buses, a strategy for coordinated charging is proposed to reduce the charging cost and decrease the load peak-valley difference of Distribution Network (DN). The load model of BSS is built based on the operation analysis of BSS and the charging data of batteries. The optimization of charging behavior imposed by the coordinated charging strategy is also presented. Finally, studies are carried out considering the Beitucheng BSS (for Beijing Olympic Games); analyses are also presented considering different number of batteries to take into account the actual configuration. Simulations show that the coordinated charging, vis-à-vis uncontrolled charging provides satisfactory results, not only reducing the charging cost but also decreasing the load peak-valley difference of DN.
Analysis of Transformer Overload Problem with EV Charging Load
Authors: Li Zong Feng , Guo Chun Lin
Published: December 2014

As a promising transport in the future, electric vehicles plays an important role in people's lives and energy conservation. In recent years, the rapid development of electric vehicles, inevitably causes the overload problems to the original grid. This paper presents a transformer load models with the consideration of electric vehicle charging load. We analyze the transformer overload problem by the results obtained by simulation of the model.
Design on Electric Power Wheel Control System
Authors: Ma Jian
Published: December 2014

This paper is designed to define the electric wheel electric wheel design task by presenting objectives, parameters, and other design requirements, combined with design methods to explore the car's electric wheel design methods, the use of electric cars simulation software for power electric wheel electric vehicles control. Last we conclude that with a reference to the next round of electric power control study.
Braking Energy Recovery Research for Electric Vehicles
Authors: Zhu Wen Bo , Ji Fen Zhu
Published: December 2014

For the electro-hydraulic braking system in the electric vehicles, a coordinated control strategy of the motor braking and hydraulic one was proposed, which includs electric vehicle braking intention recognition model contains the brake pedal and the accelerator pedal. The simulation mode was built by using Cruise and Matlab/Simulink. The braking stabilities were simulated at different adhesion coefficient and braking intensity. The simulation results show that: Regenerative braking strategy for electric vehicles under braking energy can be recovered under different conditions, braking energy recovery rate in the early 100km / h speed low intensity braking conditions can reach 73.2%. And regenerative braking results validate the feasibility of the effectiveness of coordinated strategies to match the vehicle's power to improve the electric car electric-hydraulic brake energy recovery efficiency.
Applicability Research on Evaporative Cooling Technology in Hunan Province
Authors: Ouyang Qin , Kou Guang Xiao , Ouyang Min
Published: December 2014

According to the climate conditions of Hunan province and the design parameters related to air conditioning, the energy consumption and the related characteristics of the liquid desiccant evaporative cooling system (LDECS) are compared with primary return air conditioning system. The results show that energy consumption of LDECS can be decreased by 11.78% compared to the primary return air system. LDECS has a certain degree of energy saving potential in Hunan province, especially when waste heat is available.
Effects of Fuel Flow inside the Nozzle on Spray Characteristics of Butanol/Diesel Blends
Authors: Wu Jian , Hua Yang , Shang Wei Wei , Liu Yi Bin , Xu Bin
Published: December 2014

In order to build an accurate spray model for studying the characteristics of n-butanol and diesel blends. First, the calculation of gas-liquid two phase flow inside the nozzle was carried on, the birth and development of cavitation and the non-uniformity of the velocity field inside the nozzle were analysed. Then the spray model coupled flow inside the nozzle was established and verified. The spray simulation calculation of n-butanol and diesel blends was carried on by using the model, and compared the results with the results of flow inside the nozzle not coupled. The results show that the droplet speed, spray penetration and SMD of D100 and N40 is all bigger under the condition of without coupling flow inside the nozzle. The flow inside nozzle will affect the whole spray process and spray characteristics, which will ultimately affect the combustion and emission characteristics. So the spray model coupled flow inside the nozzle can provide accurate initial condition for spray calculation, which can reflects the fuel spray characteristics truly.