bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimize of the Structure of the Grinding-Driller Based on Deform-3D
Authors: Zhang Ping Kuan , Wang Hui Lin , Sun Wang Lu , Qin Duo
Published: June 2014

The process of single abrasive in grinding-drill is simulated by using of deform-3D. The reasonable rotation and feed are achieved. Then the really process of grinding-drill is simulated. It is analyzed that deferent face structure of grinding-driller influences grinding-drill process. The reasonable taper vertex angle and amount of eccentric of the grinding-driller are obtained by means of the smallest axial force & torque & lower cutting temperature. So that the reasonable face structure of grinding-driller will be achieved.
Planning and Simulation of the Rule-Based Trotting Gait of a Bionic Quadruped Robot
Authors: Liu Ze Guo , Ding Xiang Fang
Published: June 2014

In order to make the quadruped robot walk stably with trotting gait, this paper analyzed the animal's motion to get the rule-based gait sequences and used the half wave functions and cosine functions to plan the functions of every joint combining cyclical motion. Also, on the basis of the obtained gait, the virtual prototype of a bionic quadruped robot was established and kinematic and dynamic simulations were done. The simulation results show that the motion functions can make virtual prototype of the quadruped robot walk stably and the rule-based gait planning method is accurate and reasonable.
Effect of Y2O3/La2O3 Proportion on the Mechanical Properties of Cf/SiC Composites
Authors: Zhang Yun Long , Zhang Yu Min , Hu Ming , Li Jin Ping
Published: June 2014

In this paper, the commercial α-SiC powder and bargain price La2O3/Y2O3 additives were utilized to fabricate SiC matrix composites. The influence of the Y2O3/La2O3 molar proportion on the microstructure, mechanical properties of the Cf/SiC composites were researched. The results showed that La2O3/Y2O3 additives could not enhance mechanical properties for the Cf/SiC composites distinctly. The flexural strength for the Cf/SiC composites with different Y2O3/La2O3 proportion was higher than 250MPa. The multi-toughening mechanics including grain bridge, crack deflection and fiber pullout were responsible for improvement of fracture toughness.
Research and Application of Deburring in Continuous Casting Machine
Authors: Zhao Chuan Zun , Yan Zi Han
Published: June 2014

The reason and harm of deburring in continuous casting machine, Based on the disk cutter type deburring technology in continuous casting machine system working principle and Application, The effect of deburring for the production practicek, And pointed out that in the process of debugging and operation of common breakdown and processing method.
Research and Application of Fuzzy Synthetic Evaluation Method about the Design Quality of Industrial Products
Authors: Chen Wei
Published: June 2014

In the paper, some traditional evalution methods for design quality of industrial products are reviewed, their shortcomings are analyzed, and the evaluation principle and evaluation system about them are put forward, which are practicality, economy, aesthetics and innovation. In according to them, some factors affecting them are analyzed. All of these factors are ambiguous, such as function, structure, use, material, agreeablness, securiyt, budget cost, market, traditional culture, aesthetic standards ,times, national style, new material and tcchnology, modern consciousness, outstanding individual character, advanced and so on. So a mathematical model about synthetic evaluation by fuzzy theory is established. On the basis of this model, the evaluation method is carried out for design quantity of industry product. This expresses that the evaluation method is feasible, and its conclusion is scientific.
Research Methods of the Performance of Plate Heat Exchanger
Authors: Wang Ya Nan
Published: June 2014

this paper introduces research of plate heat exchanger, and describes the working principle of a plate heat exchanger. Plate heat exchangers have many advantages.For example: high heat transfer efficiency, small end temperature, pressure drop, saving space, saving installation costs. This paper analysis performance of experiment test , making plate heat exchanger improved.
Research of Machine Tap
Authors: Song Zhi Dong
Published: June 2014

The tapping cutter bar is developed to replace the manual tapping of internal thread to obtain machining accuracy and efficiency for large batch of machining internal thread of small diameter, which is a tapping tool for machine use featuring economic and practical as well as helping to solve the problems of low efficiency, inferior accuracy and easy-breaking of tappers.
Research on Cylinder Head Thermal State Simulation
Authors: Sun Zhao Hui , Liu Zhen Tao
Published: June 2014

The thermal state of the cylinder head has a huge influence on its fatigue and damage situation; therefore it is essential to accurately simulate the thermal state of the cylinder head during engine operation. In this paper, a method research of the cylinder head thermal state simulation test has been done. A thermal state simulation test bench has been launched, using induction heating and water-cooling to regulate the temperature. A series of cylinder head surface temperature field simulation tests has been accomplished. Compared to the actual engine test results, the temperature simulation results have an average error of less than 5% and a maximum error of 8.5% in these temperature test points. It turns out that the test bench can simulate the actual cylinder head temperature distribution accurately and will has significant effects on the research of the cylinder head thermal stress distribution and thermal fatigue situation.
Annealed Treatment Effect on the Mechanical Properties of the Cf/SiC Composites Using Y2O3/ Al2O3 Additions
Authors: Zhang Yun Long , Zhang Yu Min , Hu Ming , Li Jin Ping
Published: June 2014

In this investigation, the rare-earth oxide Y2O3combined with Al2O3served as sintering additives and commercial α-SiC powder were applied to fabricate Cf/SiC composites by hot-pressing sintering. The results proved that combination of Al2O3and Y2O3sintering additives was effective for densification of Cf/SiC composites. The influence of annealed temperature on the phase constitution, microstructure and mechanical properties of the Cf/SiC composites was detailed. The combination of grain bridging, crack deflection and fiber debonding can improve fracture toughness. Keywords: Pressing sintering, Mechanical Properties, Annealed Treatment
Simulation and Springback Verification for Rubber Bladder Forming with a Definite Aircraft Part
Authors: Zhang Ling Yun , Zeng Yi Pan , Wan Gui Bo
Published: June 2014

Springback is a main problem in sheet metal rubber bladder forming that influences the geometric accuracy of a part. In this paper, springback distribution of a certain aircraft part is analyzed by finite element simulation and verified the accuracy of relevant equations. The aircraft part is divided into six convex flanging areas for analysis, several technological parameters are taken into consider, and the results of simulation and equation calculation are well agreed, the influence of a joggle is also discussed.
ST16 Oil Sump Stretching Technology and Die Design
Authors: Yang Hong Cai , Wu Ming Qing
Published: June 2014

the engine oil pan, materials for ST16, tensile depth of the parts is bigger, the design of the mould is very important to the success or failure of the drawing process to appear. The drawing process design, the engine oil pan drawing die general assembly drawing and work process analysis, finite element simulation, the engine oil pan tensile drawing process and die to improve oil pan.
Study on Configuration Design of the Multi-Payload Adapter for One Vehicle with Multi-Satellite
Authors: Gao Yong Xin , Yang Dong , Xin Qiang , Chen Yin Xin
Published: June 2014

Constellations of small satellites have a promising use in satellite remote sensing or satellite communication. Launching several small satellites at the same time with one vehicle is a good way to keep the budget of the whole project under control. Multi-payload adapter is an important equipment on the launch vehicle to carry those small satellites during the rising phase and shoot them into their own trajectories during the orbiting phase. The paper studies the relations between the demands of small satellites launching and the multi-payload adapter designing. Also the paper illustrates the necessity of putting the multi-payload adapter into a project and the necessity of researching on the multi-payload concurrent experiment.
Study on the Mechanical Process of a Automobile Thin-Wall Parts
Authors: Zhou Xiao Ping
Published: June 2014

A frame is an automobile parts, narrow, thin wall and bending，This paper mainly analyzes its machining technology andthe key, the difficulty of processing；And studies how to save materials, save the auxiliary tools, improve the machining efficiency.
Study on the Simulation of Temperature Field of Diesel Engine
Authors: Wang Ya Nan
Published: June 2014

In the case of each parameter Pistons have been basically provided ,to simulate the temperature field of Diesel Engine Piston, detailing the analysis of diesel engine piston transient heat steady state and heat transfer transient of the calculation process, providing a general simulation method of temperature field in general diesel engine piston.
Study on the SNR Gain of RAKE Demodulator
Authors: Zhu Chu Rong , Fu Hai Yang , Jia Xiang Dong
Published: June 2014

Classic RAKE demodulator(RAKEDE), multi-carrier coherent RAKEDE and RAKEDE with two antennas are given in the paper. According to those schemes provided, the GSNR, which means the gain of signal to noise ratio (SNR), for those three kinds of RAKEDE is derived, and the closed form of the expression for GSNR of those three kinds of RAKEDE is given in the paper. Comparing with those performance evaluation methods of RAKEDE existed, the method derived in this paper on the basis of diversity reception is more usable and easy to be accept.
First-Principles Study on Electronic Structure of 15R-SiC Polytypes
Authors: Zhang Fu Chun , Gao Ying , Cui Hong Wei , Ruan Xing Xiang , Zhang Wei Hu
Published: June 2014

To study the geometrical and electronic structure of 15R-SiC polytypes, the lattice parameter, band structure, density of states (DOS) and charge density of 15R-SiC are calculated by using density functional theory based on the plane wave pseudopotential approach, and electronic structure and ground properties of 15R-SiC are investigated by the calculated band structure and DOS, the results show that 15R-SiC is an indirect band gap semiconductor, with calculated indirect band gap width being 2.16 eV and band gap dependent on Si 3p and C 2p states. While charge density results show that Si-C bond is a hybrid bond semiconductor strong in covalent bond and weak in ionicity, characterized by intense sp3 hybrid characteristics, which is in accordance with the experimental results. The above mentioned results are considered as theoretical reference for design and application of SiC polytype materials.
The Application of Tool Nose Radius Compensation in the Numerical Control Turning
Authors: Huang Qi Hong
Published: June 2014

Tool nose radius compensation function is widely used in the numerical control turning, it is the key and difficult point for the numerical control turning .Correct and flexible use of tool nose radius compensation function is very important for the machining precision control of conical surface, circular surface and curved surface and improving the service life of the cutting tool.
The Fracture Failure Analysis of Precision Centrifuge Spindle
Authors: Zhang Wei Feng , Yan Li , Zhang Fu Xia
Published: June 2014

For the problem of high-speed rotating centrifuge spindle fracture failures, relevant analyses are conducted from the perspective of microstructure, chemical composition and fracture mechanics by using scanning electron microscopy and related instruments. Experimental results and analyses indicate that the spindle fracture is fatigue failure, mainly caused by cold cracks generated on the journal surfacing. Based on the analysis results, improvements and measures are suggested to better solve the spindle weld fracture failure problems.
The Influence of Performance of W-Type Metallic Sealing Ring with Different Outer Arms Open Angle
Authors: Ding Xiang Yu , Yu Qiang
Published: June 2014

In order to improve the mechanical properties of W-type metallic sealing rings used in aviation engine, using ANSYS finite element to analysis the stress distribution. By analyzing the influence on the stress distribution situation with the different outside arm open angle of W-type metallic sealing ring, get the relationship curve between the outer arms open angle and the stress.
The Multi-Body Dynamics Analysis and Experiment of Long Distance Steel Belt Transmission
Authors: Chen Zhi Ping , Xu En Dao , Zhang Zhen Jie , Mou Shuai , Yue Shi Feng , Zhang Ju Yong
Published: June 2014

This paper establishes the dynamic model of the long distance steel belt friction transmission with multi-body system rigid-flexible coupling dynamics theory, employs the boundary element theory to research the setting of the boundary conditions, and then improve the reliability of the simulation and calculation. This paper simulates and analyzes the relationship between pre-load and load,as well as that between stress and strain,so that gets the better transmission accuracy. Starting with experiment, this paper researches on the tension characteristics, running deviation and transmission accuracy of the long distance steel belt. by comparing the result of the simulation, this paper obtains the fitting function of the pre-load of the long distance steel belt and proves it have high transmission accuracy under certain condition which has proper pre-load and load.The experiment shows that the home-made precision friction transmission testbed has the ability of precision transmission. Taking advantage of the friction transmission features of steel belt, it can solve the low transmission accuracy of conventional belt transmission which results from small Elastic modulus and big elasticity sliding motion, and fulfills the long distance friction transmission on the engineering, the deviation can be smaller than 0.5%.
The Simulation Analysis of the High Speed Switch Valve Control the Cartridge Valve Based on AMEsim
Authors: Qin Yan Jin , Wu Zhang Yong , Mo Zi Yong , Wang Xian , Wang Juan
Published: June 2014

To establish the mathematical model of the system of high speed switch valve control the cartridge valve based on analyzing the working principle of the system,and then to analyze the impact of selecting different input signal of high speed solenoid valve and different duty cycle of PWM pulse width modulated signal through simulation software AMSEsim. The results obtained in the high-frequency performance is not very satisfactory, but in the low signal and moderate duty cycle, high-speed switch valve can be good linear control of the cartridge valve.
Theoretical Analysis of Flying Characteristics for Air-Helium Filled HDD
Authors: Mongkolwongrojn Mongkol , Kuanoon Kunchit
Published: June 2014

This paper presents the flying characteristics of air-helium filled hard disk drive for a self-acting two rails flat slider bearing. Numerical scheme based on the finite difference with multi-grid multi-level technique were implemented for the ultra-low flying height sliders. The characteristics of air-helium filled HDD have been examined in this research work. The results shown that the change of flying height is significantly for various fraction of air-helium filled, at various operating conditions such as temperature velocity and mass of slider. Increase of velocity, flying height increase. Increase both the temperature and the mass load, flying height decrease. Increasing of fraction in helium gas, the flying height decreases rapidly for 40% to 60 % of fraction in helium filled. The flying height for air-helium filled magnetic flat slider head equal to 1.3 nm at trailing edge with mass load 12 mN and velocity 20 m/s. The spacing for helium filled hard disk drive is lower than 3 nm when compared with conventional air filled hard disk drive.
Transmission Error Calculation Based on Manufacturing Errors and Load
Authors: Tang Jian Jie , Tang Jin Yuan
Published: June 2014

A valid mathematic model is introduced to study the calculation of gear meshing transmission error, which is based on the manufacturing error and gear teeth deformation. Subsequently, take a pair of specific gear for example;The transmission error curves are obtained by the calculation model. The results show great consistency with the curves from Romax software, which indicates the validity and high accuracy of the mathematic model presented above. And it can be found that the shape change of transmission error curves affected mainly by the pitch error under the same conditions as the precision.
Variety of Liquid Filling Machine PLC Hybrid Control System Design
Authors: Ma Jia Xing
Published: June 2014

Three mixed liquid filling control , for example, the three liquid by mixing , stirring after the motor in order to reach a certain temperature output of the mixed liquid container . And the formation of cyclic state. Control system design liquid mixing operation taking into account the continuity of their respective controlled and interconnected equipment operation between different working conditions, the control output of the corresponding action in order to achieve a liquid mixture from a liquid system by adding to complete such a cycle the output to the mixing control operation program . Liquid mixing system designed to control the center , from the control system hardware components, software selection to the system design process ( including design, design process , design requirements, ladder design , external connections and communications ) , which aims to design and production process to make a brief introduction and description.
1 Design
Throughout the design process is based on the design thinking process for equipment installation, operation, maintenance and protection services . Designed to prepare written about in accordance with national electrical automation engineering design of electrical equipment used basic graphic symbols (GB4728) and other relevant standards and specifications . Design principles include: working conditions ; specific information works on the electrical control circuit provides. System in ensuring the safe, reliable, stable, fast premise , as far as possible the economic , reasonable, combined , reducing equipment costs. In options , the more consideration new technologies, new product selection components . Controlled by a manual control to automatic control, analog control to the microcomputer control , so that to realize the function by a numerous and more perfect .
To realize the entire liquid mixture control system design , need to realize how each switch and solenoid valve control motor starting to consider this perspective , the question now is how to achieve and choose what method to determine system solutions .
Vibration Control of Space Truss Structure with Viscoelastic Laminated Composite Damper
Authors: Jia Bao Xian , Gao Feng , Bian Wen Feng
Published: June 2014

This paper works on the vibration control of the space truss structure. The damper made of viscoelastic composite was designed according to the configuration parameters of the truss structure. The parameters of damper were obtained by using the method of modal strain energy. The optimal position configuration of the damper was determined. The truss in the time domain and frequency domain was analyzed. The dynamic characteristics of three structures which are without damper, with damper in the random position configuration and with damper in the optimal position configuration were compared in the sweep excitation and pulse excitation. The result shows that the structure with damper in the optimal position configuration has a great improvement in the amplitude of vibration in the first resonance region and the amplitude attenuation of the truss. The space truss structure with viscoelastic composite damper has excellent vibration control effect.
Wearing Fault Diagnosis Application of Reciprocating Membrane Pump Based on KPCA
Authors: Pei Yu Chi , Fan Yu Gang , Liao Yun , Liu Jun Hui
Published: June 2014

Reciprocating Membrane Pump is the main power output device in the process of slurry pipeline transportation. Wearing fault of Reciprocating Membrane Pump is very difficult found by the tiny change of observation variables at the beginning of the development , observation variable and output are high coupling and strong nonlinear. This paper proposes Wearing Fault Diagnosis Model of Reciprocating Membrane Pump based on KPCA. First, fault detection model of Kernel Principal Component Analysis is established by using the history monitoring data of the normal operation of Reciprocating Membrane Pump and fault signal is detected by using the model of T2 and SPE statistics. After fault detection, positioning the wearing location through calculating the contribution of each variable. The experimental results show that the method is effective to the wearing fault diagnosis of Reciprocating Membrane Pump.
Design of Enclosure Assembly for Q450 Pellet Molding Machine Based on Solidworks
Authors: Yuan Da Long , Yuan Xiang Yue , Chen Zhong Jia
Published: June 2014

In this paper, Q450 pellet molding machine with plunger-roller ring die has been designed by employing the CAD/CAE system, Solidworks, and the load conditions of three molding assemblies fixed inside have also been studied. Then a method of FEA was conducted to research the mechanical properties of enclosure assembly for this pellet molding machine in Simulation, which is a FEA module of Solidworks. As a analysis result, the maximum stress and displacement of enclosure bodies are separately 31.37Mpa and 7.583e-2mm, that convincingly verifies enclosure assembly has reliable strength and stiffness, which ensures that Q450 pellet molding machine has enough reliability and security.
Investigation on the Structural and Optical Properties of ZnO Thin Films Prepared by Sol-Gel Method
Authors: Xiao Zong Hu , Luo Yong Ping , Xu Shun Jian , Zhong Wei , Ou Hui , Wu Huan Wen
Published: June 2014

Zinc oxide (ZnO) thin films were prepared by sol-gel spin coating technique, which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NKD thin film analysis system and fluorescence spectrophotometer. The results show that ZnO thin films with the each layer thickness of 80 nm present obvious c-axis orientation. With the increase of coating layers, the c-axis orientation characteristic weakens. The reason is considered that the growth mode of ZnO thin films transforms from layer growth to island growth. For the ZnO thin film with 4 layers, it has a compact surface and a uniform particle size of approximately 50 nm, and the photoluminescence (PL) spectrum primarily consists of two PL emission bands, one is a strong and narrow ultraviolet (UV) emission band, another is a weak and broad luminescence emission band from 400 nm to 650 nm. The average transmittance in the visible range is beyond 90%. A optical band gap of 3.26 eV, slightly less than the intrinsic band gap width of 3.37 eV, is obtained by Tauc plotting method. The defects, such as Zn or O vacancies, grain boundaries, are considered to be the main factors causing this situation.
Overview of the Status of Research on the Behavior of Beam-Column End Plate Connection Joints of Steel Frame
Authors: Yan Zhu Ling
Published: June 2014

This paper introduces the concepts and characteristics of beam-column end plate semi-rigid connection joints of steel structure, analyzes the current status of studies on various performance of semi-rigid extended end plate bolted connection joints of steel frame at home and abroad, as well as the shortcomings of existing studies on end plate bolted connection joints of steel frame, and on these bases, makes suggestions on the contents need to be studied further regarding this type of connection joints.
Research Status of Seawater Desalination System
Authors: Shi Cheng
Published: June 2014

Firstly, this paper introduces the development status of seawater desalination system, and analyzes significance of seawater desalination in today's energy shortage situation . The seawater desalination methods mainly include thermal method, membrane method and electrochemical method. The working principle of them is introduced in this paper.
Self-Diagnosing and Warning System of Wind-Induced Damage for Large-Span Spatial Steel Structure
Authors: Gu Da Hai , Xiao Chun , Zhang Xing Fei , Hao Xue Ping , Liu Hui
Published: June 2014

The damage of Large-span Spatial Steel Structure (LSSS) can destroy the entire engineering project, and wind-induced weld tensile damage is a structural damage, which is more likely to occur. Some damaged nodes may not immediately endanger the safety of the structure. To a certain extent, the damage can lead to the collapse of the structure, resulting in large number of casualties and property loss. In order to discover and prevent these dangers in advance, an experiment about Large-span spatial wind-induced damage self-diagnosing and warning system is designed in this paper. Firstly, the equivalent structure model that can reflect the structural damage is built; secondly, some nodes’ load information is obtained by sensors and is delivered to computer; thirdly, the information of damage is analyzed; finally, virtual instrument and database sharing technology is used to establish a damage self-diagnosing and warning system. The results show that the system can monitor wind-induced weld tensile damage and remotely send real-time information to users.
Modeling and Numerical Simulation Analysis of Chemical Plume in Flow Field
Authors: Meng Xiang Yao , Qiu Zhi Ming , Zhang Peng
Published: June 2014

A new discrete chemical plume model based on CFD was established, which avoids the shortcomings of the current model. In this model CFD was applied to simulate the turbulent environment of chemical plume, while the chemical substances contained in the plume were modeled as discrete phase. Utilizing this model, chemical plume under water was simulated numerically and analyzed hereafter. The transport characteristics of simulated plume were consistent with existing experimental results. Based on the simulation results, the effect of flow field on plume transport was also analyzed. The model proves an efficient approach to simulate the transport process in different environment, as well as analyze various types of actual situations. Moreover, this model can provide the theoretical basis for plume tracking algorithm research and simulation platform, which promotes significantly the research on chemical plume tracking.
Research on Unified Expression Method of Multi-Domain Constraint Models
Authors: Liu Tin Tin , Chen Guo Jin , Gong You Ping , Li Zhi Hua
Published: June 2014

This paper is mainly discussed the establishment of the unified constraint expression of simulation optimization model. Express all kinds of element constraints with unified physical mathematical mapping mechanism, uniform the model representation of product components in each domain and establish the unified expression model, in order to facilitate the follow-up simulation solution of multi-domain constraint system.
Determination of LED’s Efficacy for Lighting Application
Authors: Man Yu Yan , Zhang Chi , Xi Xiao Guang , Wu Ming Lei , Dong Yan Wei , Sun Zhao , Zhou Xiao Li
Published: June 2014

The efficacy and its degradation of light emitting diode (LED) are related to its PN junction’s temperature (Tj). Currently efficacy in certain Tjand thermo-resistant are defined for the thermal characteristics. In the paper samples from different manufacturers were tested for their efficacies and dependency relationship on Tj, results were investigated and show that current definitions on thermal characteristics are quite inconvenient or unreasonable for general lighting application. Then a new definition of LED’s efficacy was suggested for general lighting application.
Application of Reactive Power Optimization in Power Grid in AVC
Authors: Li Yan Hong , Zhang Zhi Rong
Published: June 2014

Automatic voltage control(AVC) is the highest form of current power grid voltage and reactive power control,during the implementation of AVC, the whole network reactive power optimization isthe core and foundation. Thispaper researches and discuses the application of reactive power optimization inpower grid AVC. In the traditional reactive power optimization, the reactivepower limits of synchronous generators are fixed. In this paper, thesynchronous generator PQ operating limits change with external conditions,thus establishes reactive power optimization model in accordance with therequirements of AVC. Thispaper presents reactive power optimization method based on the principle ofpartition. The method decomposes the system to several partitions. Eachpartition separately optimized, thus reduces the system scale.And the convergence of the algorithm, the calculation speed and the discretevariable processing etc. improve. At the same time, this method reflects theclassification, hierarchical, partition, characteristics of coordinated controlof AVC.
The Draw of Chinese Children 2D Body Template Based on Cero
Authors: Zhang Tie Cheng
Published: June 2014

In order to implement Ergonomics analysis uesd the model of Chinese Minors 2D body template in the design process. Model 2D body in Creo has been studied, According to human dimensions of Chinese minors. Detailed illustrate the process and precautions of model 2D body template in Creo, Using 2D templates inspect the Ergonomics issue in school desks and chairs as a case study.
Damping Characteristics Analysis Based on Complex Torque Coefficient Method in Sub-Synchronous Oscillations
Authors: Chen Han , Guo Chun Lin
Published: June 2014

Because of China's energy and load imbalance, large-scale long-distance power transmission becomes inevitable. Under this background , series compensation capacitor in the power system and HVDC developed rapidly, and the SSO (Sub-synchronous oscillations) caused by HVDC is becoming increasingly apparent. Fundamental reason of SSO lies in the sub-synchronous system negative damping characteristics, so it is necessary to analyze the system damping characteristics. The net system damping includes mechanical and electrical damping. Based on small-signal test method-complex torque coefficient method in the time-domain simulation , paper analyzed the system electrical damping and mechanical damping characteristics.
Dynamic Analysis of Tunnel Blasting Excavation Effect on Overpass
Authors: Xin Chun Lei , Gao Bo
Published: June 2014

Although drilling and blasting method is widely used to excavate tunnel structures, it has great effect on adjacent ground structures. In order to find out the influence sphere and features of this construction method on overpass, three-dimensional numerical simulation method was used to analyze the displacement, stress and blasting vibration velocity of overpass. The results show that: (1) Drilling and blasting excavation method can cause differential settlement of stratum and overpass which is above the crown of tunnel. (2) The strong constraint structures of overpass are obviously affected by blasting vibration than other parts. (3) It should be taken extra protection measures at connection points between piers and decks as well as connection points between piers and stratum. (4) Horizontal vibration velocity caused by blasting excavation is lower than vertical vibration velocity. To control the vertical blasting vibration velocity is the essential to control the security of tunnel structure and upper structures. The above results certainly contribute to construct tunnel structures by using drilling and blasting excavation under complicated conditions.
Electric Power Dispatching Operation Danger Point Analysis and Control Research
Authors: Xu Juan , Huang Ya Fei , Wang Zhi Xin
Published: June 2014

the safety of power grid scheduling is the key to ensure the safe and stable operation of power grid. Scheduling work dangerous point analysis, formulate measures, strengthen precontrol is important means to ensure the safety of power grid. Introduces the analysis of the dispatching work dangerous points and preview. This paper expounds the main work and status quo of power system dispatching operation management, and puts forward solutions.
Effect of Step-Heating on Microstructure and Mechanical Properties of Linear Low Density Polyethylene/Multi-Walled Carbon Nanotube Composites Prepared via Melt Mixing Process
Authors: Boonphan Samor , Singjai Pisith
Published: June 2014

Step-heating (single-and four-step heating) was used in the melt-mixing preparation of linear low density polyethylene (LLDPE)/multi-walled carbon nanotube (MWNT) composites. The MWNT in the composites were used at volume fractions of 0, 1, 3, 5, and 10 vol% (four-step heating), and 0, 1, 3, and 5 vol% (single-step heating). The effects of the heating steps on the microstructure of the LLDPE/MWNT composites were studied. An ultimate tensile testing machine and an impact testing machine were used to characterize the mechanical properties of the composites. The sample prepared using four-step heating had a lower porosity than the sample prepared using single-step heating. The sample with 3 vol% MWNT that was prepared using four-step heating had tensile strength, elastic modulus, and impact strength values that were higher than those of the other samples.
Environmental Study on the Behavior of Water Drops with Circular Resin Insulator Material under DC Electric Field Stress
Authors: Phimmasene Soukvilay , Tonmitra Kittipong , Siritaratiwat Apirat , Kaewrawang Arkom
Published: June 2014

The influence of damages on the insulator’s surface in the distribution system is investigated in this paper. The circular resin is used as the specimen under high voltage direct current (HVDC) between the electrodes with diameter of 2 mm and distance between both electrodes are 35 mm. There are three cases in the experiment and it was tested in environmental condition under dry surface, single droplet and double droplets. The HVDC had been applied to the electrodes, the level of applied were 5, 10, 15, 20, 25, 30 and 35 kV. The results show that the arc occurs rapidly in the case of single and double drops with compared to dry surface. The movements of the water drop of the single and doubles are pretty similar, but the arc occurs quickly in the double drop in comparison with single drop owing to double drops stretch to each other. The double drops take a lower voltage on stretching, whereas the single drop takes higher because the double drops have much more densities than single drop. Besides, the double drops act as a bridge allow the electrical field generated from both electrodes pulled them resulting in arcing easily. In conclusion, the droplets on the surfaces cause the leakage current and it has an effect on the stability of the distribution system.
Experimental and Modeling Studies on Thermal Conductivity of Cement Composites Containing Nanosilica
Authors: Jittabut Pongsak , Chindaprasirt Prinya , Pinitsoontorn Supree
Published: June 2014

This research article was presented the thermal conductivity of cement pastes containing nanosilica. The effects of nanosilica particle size and concentration determined by mixing three nanosilica particle sizes of 12, 50 and 150 nm, using nanosilica were of 1-5 wt%. The water to binder ratio of 0.5 was used. The thermal properties test were subsequently measured in terms of thermal conductivity coefficient using ISOMET 2114. The thermal conductivities of cement paste is thus numerically calculated and the predictions are compared with the existing experimental data. A unifying equation for four fundamental effective thermal conductivity structural models (Series, Parallel, one-dimensional heat flow, Maxwell’s model) was derived. The best prediction was provided by a composite model that combined the Maxwell’s model. Consequently, applications of nanosilica cement paste in building constructions may be an interesting solution in order to improve sustainability and building energy efficiency.
Investigate Oxygen Content in YBa2Cu3O7-δ Superconductors
Authors: Kruaehong Thitipong
Published: June 2014

The YBa2Cu3O7-δ(Y123) compounds were synthesized by solid state reaction method.
The home-made four-probes apparatus was used for the resistivity measurement. The highest Tc is 91.95 K in sample C and sample A has lowest Tc onset at 89.85 K. The crystal structure properties and oxygen content were characterized by powder X-ray diffraction using CuKα radiation
(λ=1.5406 Å). The Pmmm and Pnma space group corresponding on the superconducting phase and the non-superconducting phase. The atomic position of samples were consisted of various element atom. The longer time of oxygen-doping, the increase the critical temperature , superconducting phase and c lattice parameters.
Investigation of the Properties of Soda-Lime Silicate Glass Doped with TiO2
Authors: Meechoowas E. , Pantulap Usanee , Jitwatcharakomal T.
Published: June 2014

In this study, the properties of re-melted soda-lime silicate glass cullet doped with TiO2were investigated in order to study the potentials to use as parent glass for glass-ceramics. TiO2of 0.5, 1 and 3 mol% was doped into the 71SiO2-10Na2O-6K2O-5CaO-4MgO-2SrO-TiO2-Al2O3glass cullet and melted at 1500°C for 3 hours, and then annealed at 550 °C. The optical and physical properties were examined. It was found that the refractive index and density of glasses were raised with increasing of TiO2concentration. The optical properties measured by UV-Vis spectrophotometer showed that the UV edge in the absorption spectra was shifted to a higher wavelength, and the transmission at 583 nm was decreased. The CIE L*a*b* color measurement showed that the glasses were slightly colorless but the appearance of yellow increased with higher TiO2concentration. Lower thermal expansion coefficient and higher glass transition temperature as well as the dilatometric softening point were observed as the concentration of TiO2was increasing. Finally, the calculated activation energy was 476, 493, 506 and 637 kJ/mol with 0, 0.5, 1 and 3 mol% doped TiO2, respectively. At doped TiO2of 3 mol%, the properties of glass were changed rapidly due to the substitution of [Ti4+] in local [Si4+] resulting in increasing the bond strength in glass structure.
The Exponential Repulsion and Pairing Mechanism in Bisoliton Model on the Critical Temperature of Cuprate Superconductors
Authors: Chanpoom Thaipanya
Published: June 2014

The pairing mechanism of research used the bisoliton model. The exact formular of Tc equation of cuprate superconductors which taken into account the exponential repulsion between bisoliton is derived. We find that the value of critical temperature depended on bisoliton density which confirm the experimental data that the critical temperature depended on the doping level.
Investigation on Physical and Optical Properties of Vanadium Oxide in Soda Lime Borate Glasses
Authors: Ruangtaweep Yotsakit , Kaewkhao Jakrapong
Published: June 2014

In this work, the physical and optical properties of soda-lime-borate glasses doped with V2O5 concentration of 0.0 to 2.5 in mol% have been investigated. The glass samples were prepared by the normal melt-quench technique. The results show that the density and refractive index decreased with additional 0.5 mol% content of V2O5. Then both results increased with increasing V2O5 content from 1.0-2.5 mol%. The optical absorption spectra of glass samples were measured by UV-visible spectrophotometer in the wavelength range 300-1100 nm and color coordinate in CIEL*a*b* system. The absorption peaks locate around 605 and 960 nm for all V2O5 concentration that are associated to V4+ ions and produce the brown color.
Effect of Epoxide Group in Thermoplastic Elastomer on the Properties of Polyamide6 and Low-Density Polyethylene Blends
Authors: Tuampoemsab Surakit , Riyajan Saad , Sritapunya Thritima , Pakeyangkoon Pornsri
Published: June 2014

Studies on the effect of percentages of epoxide group in thermoplastic elastomer as a compatibilizer on properties of polyamide6 (PA6) and low-density polyethylene (LDPE) blends was successfully carried out in this study. Thermoplastic epoxidized natural rubber (TPENR), made from epoxidized natural rubber (ENR) and LDPE, prepared from 3 types of ENR, i.e., ENR-20, ENR-50 and ENR-70, with the ratio of 90/10 of LDPE/ENR by weight. TPENR was applied as a compatibilizer into the blend of PA6/LDPE/TPENR at the ratio by weight of 80/20/1 by using a twin screw extruder at 235°C. All test specimens were characterized for phase morphology, impact strength and rheological behaviour. Results exhibited that phase morphology of PA6/LDPE blend was incompatible. The addition of TPENR improved the compatibility of PA6/LDPE blends. With inclusion of TPENR-20 as a compatibilizer, the uniformity and the maximum reduction of dispersed phase sized were observed. Moreover, it was revealed that the rheological properties such as shear viscosity increased when compared with PA6/LDPE incompatible blend. In addition, it was found that the highest shear viscosity and also the highest impact strength were obtained for the blend of PA6/LDPE compatibilized by TPENR-20. This result was further supported by SEM images, which showed that the smallest dispersed phase size occurred when a TPENR-20 was used as a compatibilizer. So, it was clearly demonstrated in this study that the suitable type of TPENR, i.e., TPENR-20, has an effect on improving phase morphology and properties of PA6/LDPE blends.
The Photoluminescence and Physical Properties of Eu3+ Ions in Li2O-Y2O3-B2O3 Glass System
Authors: Kaewnuam Eakgapon , Prongsamrong Pruek , Kim Hong Joo , Kaewkhao Jakrapong , Chanthima Natthakridta
Published: June 2014

The photoluminescence and physical properties of lithium yttrium borate glasses doped with Eu2O3 were studied in this work. The glasses were prepared by the melt-quenching technique and varied the Eu2O3 doped concentration between 0.00-1.50 mol%. We found that, the molar volume and density of these glasses showed linear increasing tendency with Eu2O3 concentration. The absorption bands were observed in UV and NIR region. For the Eu3+ doped glasses, the excitation bands centered at 363, 383, 394, 414, 465, 526 and 533 nm were observed with 613 nm emission wavelength. While in the emission spectra, the bands centered at 590, 613, 652 and 701 nm were observed with excitation of 394 nm. The intensity of excitation and emission bands increased with increasing of Eu2O3 concentration.
Waste Silicon Carbide as Filler for Natural Rubber Compounds
Authors: Rattanapan Apaipan , Paksamut Jitrakha , Pakeyangkoon Pornsri , Tuampoemsab Surakit
Published: June 2014

This work studied possibilities of using waste silicon carbide (SiC) particles from abrasive industry as alternative filler in natural rubber (NR) compounds. The rubber was prepared by using natural rubber grade STR 5L and waste silicon carbide loading of 0, 10, 20, 30 and 40 phr. Firstly, the rubber were compounded by using two roll mill and then using Oscillating Disc Rheometer for studying cure time at one hundred and fifty degree Celsius. Then, shear viscosity and extrudate swell of the compounded natural rubber were characterized by using capillary rheometer at 100°C. The result showed that the apparent shear viscosity increased slightly with increasing waste silicon carbide loading and the percentage of extrudate swell was found to be a decreasing function of the filler loading. Then, test tensile by using the prepared samples for studying tensile modulus, tensile strength and elongation at break. The result showed that tensile modulus and tensile strength increased with increasing waste silicon carbide. On the other hand, the elongation at break of the filled natural rubber decreased with increasing waste silicon carbide. Finally, bring the sample to test hardness by using shore A. Results indicated that waste silicon carbide direct variation with the indicator of hardness.
Detection of Pesticide Residues in Vegetables and Fruits Using Piezoelectric Crystal Biosensor
Authors: Chaiyachate Panuwat , Chaiyachate Siriwan
Published: June 2014

We propose a new device for detection of pesticide residues in vegetables and fruits using piezoelectric crystal biosensors. Piezoelectric crystal biosensors are based on the relationship between the resonance frequency of an oscillating piezoelectric crystal and the mass deposited on the crystal surface, which was well established by Sauerbrey. For the piezoelectric crystals vibrating in resonance frequency of the crystal is linearly related to the mass change on the crystal surface. In this project we used quartz crystal piezoelectric as a probe to detect pesticides in vegetables and fruits in Sakon nakhon province then compare it with the standard of toxins that are harmless to humans.
A Simple Method for Large-Scale Synthesis of Nano-Sized Zinc Sulfide
Authors: Phoohinkong Weerachon , Sukonket Thitinat
Published: June 2014

nanosized zinc sulfide (ZnS) is a special property semiconductor material widely used in many applications such as catalyst, light emitting diode, transistor, gas sensors, biosensors, UV-light sensors, and photovoltaic cell. The wet chemical method is a simple and low-cost method to prepare nanosized zinc sulfide. However, the wet chemical reaction using sodium sulfide without surfactant or template has rarely been reported. In the present work nanosized zinc sulfide particles were synthesized by simple wet chemical reaction method at room temperature and without any surfactant. The influence of sulfur source, sodium sulfide and potassium sulfide used as the reactant were investigated. The samples were characterized by scanning electron microscopy coupling with energy-dispersive X-ray spectroscopy (FESEM-EDX), and transmission electron microscopy (TEM). The results show that the nanoparticles of zinc sulfide were obtained from sodium sulfide and potassium sulfide with particles sizes are in the range of 10 to 50 nm and 25 to 50 nm respectively. In addition, from FESEM microphotograph the primary ZnS particles size of around 5 nm and 25 nm were obtained by 10% salt (sodium chloride, potassium chloride, sodium acetate) addition with sodium sulfide and potassium sulfide reactant respectively.
Effect of Annealing Temperature on ZnO Nanorods Prepared by Hydrothermal Process
Authors: Mungchamnankit Araya , Eiamchai Pitak , Chananonnawathorn Chanunthorn , Limwichean Saksorn , Horprathum Mati , Thongmee Acharawan , Sukplang Patamaporn
Published: June 2014

We presented the effect of annealing temperature on nanocrystallite growth toward zinc oxide (ZnO) nanorods based on the hydrothermal process. The hydrothermal growths of the ZnO nanorods were prepared with zinc nitrate hexahydrate and hexamethylenetetramine solution at 90°C for 6 hours. The structural, morphological, optical, and anti-bacterial properties of the ZnO nanorods, prepared at different annealing temperatures, were characterized by grazing-incidence X-ray diffraction (GIXRD), field-emission scanning electron microscopy (FE-SEM), and UV-Vis spectrophotometer. The GIXRD patterns of the ZnO nanorods corresponded to the wurtzite structure. The FE-SEM results showed that the prepared ZnO nanorods were in the form of the hexagonal shape. The anti-bacterial behaviors of suspension of ZnO nanorods against Escherichia coli (gram-negative) would be discussed in this paper.