bluuebunny/crossref_metadata_2025 huggingface dataset:
Large Amplitude Free Vibration Analysis of Functionally Graded Annular Plates
Authors: Lhoucine Boutahar , El Bikri Khalid , Rhali Benamar
Published: June 2014

The geometrically non-linear axisymmetric free vibration of functionally graded annular plate (FGAP) having both edges clamped is analyzed in this paper. The material properties of the constituents are assumed to be temperature-independent and the effective properties of FGAP are graded in thickness direction according to a simple power law function in terms of the volume fractions. Based on the classical Plate theory and von Karman type non-linear strain-displacement relationships, the nonlinear governing equations of motion are derived using Hamilton’s principle. The problem is solved by a numerical iterative procedure in order to obtain more accurate results for vibration amplitudes up to twice the plate thickness. The numerical results are given for the first two axisymmetric non-linear mode shapes, for a wide range of vibration amplitudes and they are presented either in a tabular or in a graphical form, to show the significant effects that the large vibration amplitudes and the variation in material properties have on the non-linear frequencies and the associated bending stresses of the FGAP.
Latest Development of Accuracy Recession of Numerically-Controlled Machine Tools
Authors: Liu Shang , Zhang Xiao Long
Published: June 2014

Accuracy recession is the prime cause which affects the accuracy retentivity of highly-precise Numerically-Controlled Machine Tools, and in recent years a lot of work has been done in this field at home and abroad. The current state and the progress on the research of accuracy recession of numerically-controlled machine tools were comprehensively presented. The effect of friction and wear, the mechanical structure and operation conditions on accuracy recession of numerically-controlled machine tools were described and commented as the key point. And suggestions and developing directions were also put forward aiming at the existed problems.
Lift Performance of Wind Turbine with Blade Tip Loss
Authors: Jiang Hai Bo
Published: June 2014

Blade tip losses would reduce lift and power of wind turbine. This paper analyzed the mechanism of tip losses, and according to Prandtl and Glauert tip loss correction factor and blade element - momentum theory derived the blade chord formula with tip losses. Further, lift coefficient calculation formula was obtained by integrating along the blade span. The lift coefficient formula considering tip loss expressed the highest value of lift coefficient of any practical wind turbine with tip losses. The research shows, the impacts of tip losses to chord concentrated in the tip area; tip losses will reduce the lift coefficient about 2 to 6 percent when tip speed ratio changes from 10 to 4.
Modal Analysis of Grasping Steel Mechanical Boom Based on ANSYS Workbench
Authors: Xue Feng Chao , Li Shu Mei , Liang Jian An , Liu Zhi Jun
Published: June 2014

In order to solve the problems that the vibration and deformation of grasping steel machine’s boom can affect machine’s reliability and stability under complex work conditions, the crawler electric grab steel machine JK321-GD is taken as the research object. And then the three-dimensional modeling is established by UG software, the modal analysis of grasping steel machine’s boom is also conducted using ANSYS Workbench, arriving at the the dynamic characteristics of the boom, including the natural frequency, the maximum amplitude and the main vibration direction. These provides theory basis for further optimize design.
Nondestructive Testing of the Wire Rope Fault Detection
Authors: Lian Mei Juan , Gao Guo Hua , Qin Ya Nan , Liu Yue , Song Ming Yang
Published: June 2014

With the development of nondestructive testing (NDT) technology for wire ropes, various detection methods are constantly refined and improved. The primary and representative NDT methods are suitable for the detection of wire ropes including manual inspection, acoustic emission method,acoustic-ultrasonic method,eddy current method,electromagnetic method and metal magnetic memory method. Meanwhile, the research results of our laboratory based on the theory of the magnetic flux leakage to detect wire rope’s fault detection will be displayed. Through comparisons of methods’ merits and weaknesses,it also has brought forward the new trends about adopting metal magnetic memory to predict the lifetime of the steel wire ropes,which has greater value in theory and application for improving the precise detection of the in-service ropes.
On the Application of Hall Sensor in Speed Measurement for DC Stepper Motor
Authors: Wang Juan , Wang Meng , Bu Shao Cong , Zhang Sheng Quan , Liu Yan
Published: June 2014

This paper describes the working principle of hall sensor and its application in DC stepper motor. It designs a speed detection system for DC stepper motor based on P89V51 Single Chip Microcontroller (SCM), i.e. hardware circuit diagram and software flow chart. It utilizes Hall elements to complete the conversion from speed to pulse and then process the pulse signal to get the quantity of pulse during unit interval. By means of comparison of test and theoretical data, it indicates that the speed measurement system is satisfactory for application in reality.
Radial Crushing System of Exhaust Pipe
Authors: Wang Bo , Mao Xian Chang
Published: June 2014

According to the characteristics of exhaust pipe, a radial crushing system was designed in this paper, and the focus was laid on the design and analysis of the bulging tooling and hydraulic system. Moreover, overflow pressure was calculated in detailed, and the joint strength between mandrel and hydraulic pipe was checked. The results show that the radial crushing system has the advantages of simple structure, rational design, reliable work and adaptable.
Research and Design of a Impact Drill Dust Collector
Authors: Yang Lian Fu
Published: June 2014

Impact drill is an important tool which is often used in the process of construction or decoration, mainly to complete the drilling on the cement wall or a brick wall. Impact drill will produce large amounts of dust and dirt in the use process which can bring great influence for the environment, also for construction personnel. This will also bring a lot of inconvenience for us. It is becoming important to avoid and reduce the impact. The problems in the process of the use become a need to study the problem. Here will study a method which can be a very good solution to this problem, it will bring great convenience to construction personnel.
Research on Calculation of Intersecting Line of Curved Pipes that Based on UG
Authors: Zhang Zhen Jie , Ji Guo Shun , Xu En Dao , Zhang Ju Yong , Chen Zhi Ping
Published: June 2014

In order to solve the problem in calculating the analytic equation of intersecting line which forms by two curved pipes, this paper presents a solution which based on UG. By employing UG we can extract the coordinates of discrete points of the intersecting line, then fit the discrete points with cubic B-spline curve, thus obtain the analytic equation. Finally, this paper verifies the feasibility of this method through simulation in Matlab, therefore, lays the theoretical basis for the development of flame cutting machine.
Research on Leakage Measurement Methods of Coupling Clamps for Aircraft Tubing
Authors: Li Guang Jun , Chen Xue Mei , Zhang Zhi Yong , Zhao Zheng Da , Ma Jun
Published: June 2014

By analyzing the problems of leakage measurement methods of coupling clamps for aircraft tubing, a new technical solution is proposed based on the gas-liquid volume equivalent replacement principle. The test prototype and dedicated measuring device are developed. The results show that the new measurement method is scientific, safe, reliable and with high accuracy. The measurement method has already been used in the production of various coupling clamps in aircraft tubing.
Rolling Bearing Fault Detection Method Based on Wavelet Packet Energy Spectrum - PLS
Authors: Li Fang Qian , Fan Yu Gang , Zhang Ya Xiong
Published: June 2014

For the problem of rolling bearing mechanical fault detection, this paper proposed a fault detection method based on wavelet packet energy spectrum and partial least squares (PLS). Firstly, the collected vibration signal was decomposed by wavelet packet into independent frequency bands. The different frequencies energy spectrum could be collected from the independent frequency bands. That means the energy spectrum feature vectors whose changes reflect the running state could be constructed. Then analyze the energy spectrum feature vector by PLS, and establish the fault detection model. The fault could be detected by the T2 and SPE statistics. Finally, the experimental results showed that the method is feasible and effective.
Rolling Bearings Fault Diagnosis Based on Generalized Demodulation Time-Frequency Analysis Method
Authors: Bu Yong Xia , Wu Jian De , Ma Jun , Fan Yu Gang , Wang Xiao Dong
Published: June 2014

In view of the characteristics of the non-stationary and multi-component AM-FM signals of vibration signals in the rolling element bearing, the generalized demodulation time-frequency analysis method is used for its fault diagnosis, overcoming the problem that the maximal overlap discrete wavelet packet transform (MODWPT) has no adaptability. First of all, the original vibration signal is took preprocessing by generalized Fourier; Then, using MODWPT to decompose signals after pretreatment and obtaining weights; Once again, the weights are carried out the inverse generalized Fourier transform to get the weights of the original signal; Finally, reconstructing principal component of the original signal to get the Hilbert instantaneous energy spectrum, roller bearing fault diagnoses based on the Hilbert instantaneous energy spectrum. The experimental results show that the method can effectively diagnose rolling bearing fault.
Simulation of Wind Speed for an Large Offshore Wind Turbine
Authors: Xie Yong Zhi , Mu An Le
Published: June 2014

According to the wind shear and tower shadow effect, wind speed model was established for large offshore wind turbine .Simulation of the wind speed has been fulfilled by the harmonic superposition method on the 4 special points of the offshore wind turbine, and the split-Radix FFT was introduced to improve the computational efficiency. The consistency of theoretical power spectrum and computing power spectrum of pulsating wind speed verified the rationality and validity of simulation of the wind speed.
Sliding Mode Control for Wheeled Inverted Pendulum
Authors: Shi Xiang , Xu Zhe , He Qing Yi , Tian Ka
Published: June 2014

To control wheeled inverted pendulum is a good way to test all kinds of theories of control. The control law is designed, and it based on the collaborative simulation of MATLAB and ADAMS is used to control wheeled inverted pendulum. Then, with own design of hardware and software of control system, sliding mode control is used to wheeled inverted pendulum, and the experimental results of it indicate short adjusting time, the small overshoot and high performance.
Stress Analysis and Optimization of the Hanging Centrifuge Drum Perforation
Authors: Chen Yuan , Xu Guang Heng , Yang Xu Juan , Lan Yong Ting
Published: June 2014

The stress of the two kinds of hanging centrifuge drum with different perforation shape are simulated by using ANSYS, and the perforation shape is optimized. The results show that the stress concentration of ellipse perforation is lower than that of the circular one under the same condition, and the maximum stress of ellipse perforation is minimum when the ration of major and minor axis of ellipse perforation is a/b=2.0.
Study on Damping Measures of Pump Piping Vibration Isolation Device
Authors: Wang Zhong , Chen Chang Zheng , Kong Xiang Jun
Published: June 2014

The problem about pump piping system vibration isolation that is hard to be solved at the present stage in the practice engineering was studied in this paper. Damping measures which is the necessary measure is proposed in this study. Theoretical analysis is given to the main parameter (thickness) of the influences of the damping. Based on the free damping measure, constrained damping measures was proposed and verified by the experiments. The results show that the damping effect was improved with the increasing of the thickness. Under the same conditions, the effect of the constrained damping measures was better than the free damping measures. The results have significant guidance in the isolation vibration of the pump system.
The Analysis and Diagnosis of the Reason Engine Connecting Rod's Broken
Authors: Sun Ya Li
Published: June 2014

Because of the flaw and broken of the engine connecting rod, which have a negative influence on safety of motorcycle using. Through the checking and material analyzing of breaking engine connecting rod,material performance test,macroscopic fracture analysis as well as analyzing metallographic structure is because during the manufacture process of the engine connecting rod, it is unreasonable for grinding process, adopting modified technology to improve the quality of production, keeping the safety of motorcycle using as well as boosting the profits of Lieferant, wining the praise of customers.
The Analysis of Two-Phase Flow Type in the Micro-Channel Flow Boiling
Authors: Li Dian Xun , Zhang Shu Sheng
Published: June 2014

This paper describes the measurement of the parameters of the experiment, the problems in the analysis of experimental data processing and experimental error. The flow pattern and pressure drop of flow boiling, heat flux and heat transfer coefficient of relations are studied by analysis of the experimental data. The test section were isolated three flow patterns, bubble-like flow, limited bubble-like flow and evaporated to dryness district. Only isolated bubble-like flow of a stream type such as channel width = 2.0mm thin channel, volume flow greater than 15.47L/h. For channel width =1.0mm thin channel, bubbly flows is limited bubbly flow changes corresponding volume flow 10.8L/h.
The Basic Principle of Centering of Shafting
Authors: Gao Tian Hong
Published: June 2014

this paper focuses on researching on basic theory of shafting alignment, detailed descripting of basic assumptions by finite element method, establishment of coordinate system, finite element stiffness matrix and establishment of external constraints, providing a basic theoretical foundation in the shafting study for the future.
The Crash-Box Crashworthiness Design Based on RCAR Tests
Authors: Liu Hong Lan , Hu Ning
Published: June 2014

Based on the RCAR test standards, this paper analyzed the low-speed bumper tests regulations, proposed the design principles of the crash-box and identified the key parameters to evaluate the crashworthiness of the crash-box. This paper built the crash finite element models of the front bumper system, used the finite element analysis software LS-DYNA and HYPERWORKS to simulate the crashworthiness of the crash-box based on different thickness models and completed the performance study of the crash-box. The optimized crash-box has good crashworthiness and it will provide important guidance to the crash-box design.
The Design of the New-Type Vice Wrench for Machine
Authors: Song Zhi Dong
Published: June 2014

Parallel jaws are widely used in machine tools for clamping. Vice wrenches are necessary for loading and unloading workpieces. However, it is inconvenient to use current vice wrenches. In order to improve the flexibility and convenience of vice wrenches and improve the efficiency of mechanical clamping, a new-type vice wrench is designed.
The Development of Multi-Angle Positioner
Authors: Song Zhi Dong
Published: June 2014

When machining large workpieces, the positioning block is required to fix workpieces on the bench, and clamp the workpieces to be machined. The positioning block of the machine tool can not meet the positioning needs of more parts, affecting the efficiency. In order to improve versatility, flexibility, convenience of the positioning block, a multi-angle positioner of the machine was designed.
Functional Properties of Poly(lactide) Film Incorporated with Clove Essential Oil
Authors: Wu Yan , Chen Chun Sheng , Qin Yu Yue , Cao Jian Xin
Published: June 2014

A novel antimicrobial poly (lactide) (PLA) film incorporated with clove essential oil (0, 2%, 4%, and 6% (w/v)) was developed. The mechanical property, water vapor permeability, color, contact angle, and antimicrobial activity of the films were investigated. The flexibility of films was improved by incorporation with clove. The water vapor permeability slightly increased with clove content. PLA film containing clove showed better antimicrobial activity compared to pure PLA film. The results suggested that PLA/clove blends could be a novel composite film for food packaging applications.
The Modeling and Simulation of Pneumatic ABS Pressure Regulator Based on AMESim
Authors: Ma Tian Fei , Chen Qian
Published: June 2014

The pneumatic ABS pressure regulator of commercial vehicle is submitted to study in this paper. Its structure and operating principle are introduced, and a simulation model based on the AMESim is established on the basis of its mathematical model. Then the static characteristics and dynamic characteristics are researched by simulation model and the characteristic curves are compared with experimental data for the verification. The results show that simulation curves and experiment curves are in good agreement, which can be tolerated in the engineering.
The Process of Multi-Line Triangular Thread by Axial Line Method in Numerical Control Lathe
Authors: Wang Ming Yao
Published: June 2014

this paper gains information about the method and deficiency of center lathe processing multiple thread from the aspect of processing, discusses the common method of numerical control lathe processing multi-line triangular thread from the aspect of programming, and provides reference for solving the problem on difficulty in the numerical control lathe processing multi-line triangular thread.
The Standard Wiring Practices in the Role of Boeing Aircraft Maintenance
Authors: Duan Rong Yi , Liu Ying , Hu Ling Xiao
Published: June 2014

wiring fault is a fault in the fault plane, along with the development of the aviation industry, increasing aging aircraft, how to use the manual fault and failure analysis, mature locomotive repair personnel each should master the basic skills of Boeing aircraft repair. combined with a specific fault, in conjunction with the relevant manuals, carries on the analysis to the wire and remove the fault.
The Vehicle Control Unit Selection of Microprocessor and Main Circuit Design
Authors: Wang Chun Lin
Published: June 2014

Through to the domestic and foreign automobile electronic control technology, fuel injection control, automatic control, security control, electric sunroof turn signal control and data about the development of the automatic door lock control system is analyzed, combined with the actual situation, system with the method of multiple sensor information fusion, through the intake manifold absolute pressure (MAP), rotational speed sensor and crankshaft position sensor (CPS), the coolant temperature sensor (CTS), the inlet temperature sensor (IAT), throttle position sensor (TPS), oxygen sensor, infrared sensor, cylinder signal sensor, Angle sensors, skylight, start signal signal the various states, such as electric control unit of the collected signal filtering, processing, drive actuators, implementation of fuel injection, skylight, anti-theft, turn signal, the control of car door lock.
The Status Quo of Hemispherical Parts Stretch Forming with Research and Analysis
Authors: Wu Ming Qing , Guo Ma Kun
Published: June 2014

the study on deep drawing of cylindrical carried out from two aspects of theory and experiment. For the numerical analysis of hemispherical parts deep drawing, to establish the precise forming process of stress and strain distribution and the shape and thickness distribution of mechanical parts model, is the basis of the study of wrinkling and rupture, to predict forming process possible defects such as wrinkling and rupture, and identify some of the important process parameters provide a theoretical basis. Domed parts drawing status is analyzed, and adopts the theory to carry on the numerical simulation were determined.
Analysis of Influence of Structures and Strength about Corrugated Radius of Metallic Sealing Ring
Authors: Ding Xiang Yu , Chen Xi
Published: June 2014

In order to make the design criteria of metallic sealing rings, and improve the mechanical properties of metallic sealing rings used in aviation engine, using finite element analyzing the stress distribution of three corrugated sealing rings with different corrugated radius. Finally get a preliminary design criterion of metallic sealing rings of aero engine
Performance Analysis for Spindle System of Special Friction Welder Machine Based on ROMAX Software
Authors: Feng Rui Cheng , Chen Tao , Li Hai Yan , Rui Zhi Yuan , Zhang Guo Tao
Published: June 2014

This paper focus on the spindle system of special friction welder machine with conductive device made up of aluminum electrolytic prebaked anode. The ROMAX software is employed to analyze the spindle system, and the spindle axial force and displacement, radial displacement, and natural frequency are obtained by the analysis. The reasonable result can be got by analyzing the corresponding results, respectively. Thereby, the gist to improve the fiction welder is attained.
Research and Application of Compound Lever Iron Plate Shears
Authors: Yang Lian Fu
Published: June 2014

It is becoming a difficult problem to how to complete iron plate cutting simply and effectively in the small enterprise in the practical work. We will research and development and use a composite plate shear lever, simple and economic solution to the problem of iron plate cutting.
Simulation of Liquid Meniscus and Microdrop Formation of a Capillary Gripper for Microparts Transfer
Authors: Wang Le Feng , Chu Zhao Qi , Fan Zeng Hua , Rong Wei Bin
Published: June 2014

Microparts transfer plays an important role in various micromanipulation and microassembly tasks. One typical way of microparts transfer is based on the pick-and-place method with a microgripper. Microparts have the potential risks to be damaged due to the local stress concentration when they are gripped and it is a great challenge to release them reliably due to adhesion forces at microscale. In this paper, a flexible and reliable pick-and-place transfer scheme with a capillary gripper is proposed and the principle of the transfer scheme is based on microdrop control. A series of simulations are also performed. For picking microparts, the simulation results show that meniscus can be adjusted by altering the interface pressure. For placing microparts, the controllable formation of microdrops shows the placing reliability. These results are helpful to further optimization and control of the proposed capillary gripper.
Study on Multi-Functions Vacuum Cleaner without Causing Secondary Pollution
Authors: Wang Shao Jie , Liu Zhi Xiong , Yan Shuang , Pan Chen Chen
Published: June 2014

A novel vacuum cleaner was designed and tested. The testing results showed that the PM2.5 of new cleaner was130μg/m3, compared to the traditional one was 440μg/m3when they were working in a same condition. After being used 4 months, the resistance of the new cleaner remained about 50Pa, while the traditional one was more than 200Pa. The filters replacement cycle of the novel cleaner was changed from 3 times a year to 1 time a year. The relative humidity and temperature were improved from 21% and 18oC to 25oC and 45% in the winter respectively. The amount of average bacterial content was changed from 3560 cfu/m3to 1790 cfu/m3in a closed ward of a hospital.
The Differences between Section Rigidity and Member Stiffness and their Applications in Engineering Structural Design
Authors: Hao Yan E , Lan Yong Qiang
Published: June 2014

Under the action of same loads, the sizes of deformation and internal force generated in the building structure are related to the inherent stiffness of member or structure itself. In structure design, these two basic concepts of section rigidity and member stiffness play a significant role in stress analysis of member or structure. This article summarizes the application of section rigidity and member stiffness which are often used in structural design by contrasting the definition and calculation of section rigidity with those of member stiffness, which can help the designers to understand the two concept of “rigidity” well and utilize them reasonably in real structure designs, and make the designed structural force conform to relative codes and regulations.
Development of New Multi-Function Power Quality On-Line Monitoring Device
Authors: Cheng Le Feng , Yin Lin Fei , Zhou Bin , Jiang Jing , Yu Tao
Published: June 2014

A power quality on-line monitoring device based on two CPUS is designed and implemented in this paper, which separated the data analysis from the peripheral control completely, used CPLD (Complex Programmable Logic Device) to generate control timing of peripheral devices, made full use of the DSP, so as to meet the requirements of power quality: monitoring precision and real time. The paper firstly introduces the monitor's sampling circuit, communication module circuit, storage module circuit and the flow chart of software. Then, the functions, features and designations of each module are described in detail.
Research on Latest Application of Precision and Special Processing Technology
Authors: Lin Guo Min , Zhang Wen Guang , Shang Miao
Published: June 2014

The engineering background of special processing technology and precision is given. The characteristics of precision and special processing technology are analyzed. The precision and special processing technologies are classified according to the different classification methods. The latest applications of precision and special processing technology in all areas are discussed. The development trend of the precision and special processing technology is pointed out finally.
Keywords: Precision and special processing technology; Fine processing; Overall component
30A/60V Electric Car Charger Control Circuit Simulation
Authors: Liu Ying Chun , Zhang Jian Ming , Zhang De Long , Wang Yan Yu , Hou Chun Guang , Wang Zi Ping , Liu Hua Xin , Liu Chun Rui
Published: June 2014

Through analysis and comparison of existing charging method works , adding more links constant current charging and constant voltage charging on the basis of the three-stage charging mode is proposed to receive more in line with rechargeable batteries five-phase characteristic curve charging mode. By scaling the control circuit and the PI regulator circuits use the charging current value and the constant voltage is sampled , a constant voltage corresponding to the error value to be compared and outputs the PWM control chip SG3525, causing the output current of the front end circuit chip , the regulation voltage , the error is gradually reduced until it reaches the steady-state output .
1 key components - integrated operational amplifier selection
Integrated operational amplifier control circuit for the main components , essentially the entire op-amp circuits are designed to carry around , so choose the op amp circuit is particularly important . From the foregoing analysis, the current control and voltage control portion of each part requires three op amp ( both as an amplifier , a PI controller is used ) , the entire control circuit requires access to six integrated amplifier . Out of circuit integration considerations, decided to use a quad op amp manifold and a dual op amp with the completion of the manifold .
By screening and the corresponding parameters available on the TI (TEXAS INSTRUMENTS TI ) website , and ultimately determine the use of quad op amp LF347 and dual op amp TLC2272.
Analysis and Design of Integrated Optimization of 1.5MW Wind Turbine Tower
Authors: Xie Yong Zhi , Mu An Le
Published: June 2014

This paper uses Isight_FD 5.6 to integrate UG8.0 parametric modeling, ANSYS Workbench static analysis, modal analysis, and mathematical modeling of design optimization, by means of optimization algorithm, to meet strength and the stiffness of the tower, to realize the optimization of tower structure, so as to attain the expected target which reduces the weight of tower.
Analysis of Flow Measurement Accuracy by Coaxial Phase Water Detector
Authors: Wang Jin Qi , Guo Yu Wei , Liu Shao Zhong , Zhang Ya Nan
Published: June 2014

The principle through the turbine flowmeter,establish a relationship between the flow rate measurement of Coaxial phase water detector,calculate the actual measurement accuracy,and for several factors affect the accuracy of experiments were carried out,obtained the pattern of flow measurement.
Analysis on Energy Dissipation Principle
of Buckling Restrained Brace Frame
Authors: Han Wei , Jia Xiao Yu , Meng Xian Qiang
Published: June 2014

Buckling Restrained Brace, Abbreviated as BRB in thefollowing content, a new omponent dissipating energy and absorbing quake ,as itis installed steel constrained unit to prevent overall instability ,it can notonly maintain its stiffness and stability, but also dissipate seismic energy bythe steel core material, as a result we can protect the main structure of thebuilding. This paper focuses on the buckling restrained braced frame (BRBF) ofthe energy principle、calculation method and thespecific design process.
Analysis on Simulated Experiments of Arcing Earth Fault in Low Voltage Circuit
Authors: Wang Xin Ming , Gao Ao , Zhao Chang Zheng , Gao Wei
Published: June 2014

In this article, through the simulated experiment, the fire risk of copper conductors which were in arcing earth fault of low-voltage were validated. As a result, it showed that the polyporous combustibles could be ignited easily while ignited probability of the tight combustibles were slim under the same arcing earth fault; meanwhile, the ignited probability of the polyporous combustibles were almost identical under the different arcing fault. The results aimed to provide the important references for exploring the fire scene and investigating the reasons of electric fires once the relevant evidences existed.
Analysis on Wheel-Rail Contact and Rail Cracks of 50m Radio Telescope
Authors: Chen Zhi Ping , Wang Song Gen , Kong De Qing , Zhang Ju Yong , Zhang Ya Lin , Shi Hu Li
Published: June 2014

In order to search the pointing accuracy degradation and the wheel-rail contact of the National astronomical observatory 50m radio telescope, according to the actual wheel-rail structure and design indicators, the wheel rail contact problem with the finite element analysis based on non-Hertz rolling contact theory is analyzed. The results show that the maximum deformation should be less than 1 mm. Then the measurement scheme of rail horizontal error and deformation is formulated. The mean value of the rail horizontal error is 2.89mm, while the maximum rail horizontal error is 1.5mm. The rail maintenance scheme is put forward after the flaw detection which finds large areas of cracks at the rail junction and the welded joint. The measurement is taken after rail maintenance; the experimental data coincide with the simulation results and then verify the correctness of the wheel-rail contact model, also the solution scheme of rail cracks. The reason for the pointing accuracy degradation is verified finally, which also can provide an effective method for the wheel-rail design and maintenance of large radio telescope.
Modeling Research on the Hysteresis Nonlinearity of the Piezoelectric Ceramics Micropositioning Staging
Authors: Yang Gui Hua
Published: June 2014

It is difficult to obtain precise mathematical model with the traditional methods because of the hysteresis nonlinearity of piezoceramics, and it affects the displacement output accuracy of piezoelectric actuator. The paper proposes an online modeling technique combined with neural network and genetic algorithm (GA). It make the initial parameters of BP neural network be optimized, and so improves the modeling accuracy. Experimental results show that displacement maximum error is 71nm, and the average error is 26nm in the whole trip. It meets the nanopositioning accuracy requirements of piezoelectric staging .
Drying Pineapple Using a Mix Mode Solar Dryer
Authors: Srisittipokakun Nattapon , Kirdsiri Keerati
Published: June 2014

Pineapple was dried using a mix mode solar dryer developed in the Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom, Thailand. The dryer was designed for small-scale commercial producers of agricultural products in non-electrified locations. The products to be dried are placed in multilayer on a wire mesh in the drying tunnel to receive energy from both hot air supplied from the collector and incident solar radiation on products. It is constructed in local materials then tested experimentally in food stuffs drying pineapple. With this dryer, 40 kg of pineapple can be dried within 4 days. The dryer reduces drying losses as compared to sun drying and show lower operational costs than the artificial drying. Temperatures in the drying chamber varied from 28.0 °C to 57.0 °C depend on the weather conditions. The dryer could be used for pineapple of 83% (w.b.) moisture content, and they could be dried within 4 days, with 15% (w.b.) remaining moister. In addition, pineapples being dried in the solar tunnel dryer were completely protected from rain, insects and dust, and the dried.
Effect of Surface Fluorination on Photocatalytic Activity of Titania Nano-Powder
Authors: Chuasontia Itsarapong , Hathaisamit Khanitta , Putwat Sayan
Published: June 2014

This work, surface fluorination process was used for improvement photocatalytic activity of TiO2. Photocatalytic activity was observed by degradation of methylene blue (MB). TiO2 nanopowders were prepared by sol-gel technique from titanium-tetraisopropoxide (TTIP): 2-propanal (2-PP) with the ratios of 1:5, 1:15, and 1:30 (V/V) then adjusted pH by nitric acid at 2. The result showed that grain size of TiO2 powder decreased as 2-PP ratio increase. The grain sizes of TiO2 were in the range of 14-25 nm. Photocatalytic activity was considered by characteristic time constant. The results showed that F-TiO2 presented higher photo-degradation than naked TiO2. At 1:30 for TTIP: 2-PP ratio with improvement by surface fluorination (F-TiO2) could degrade MB faster than other samples under weak-UV at irradiation time of 1 hr. The 1:30 sample degraded MB reach to 96%. The results led to conclude that surface fluorination is the good process to improve photocatalytic activity for TiO2.
Impact Modification of Wood Plastic Composite from Acrylate-Styrene-Acrylonitrile and Bagasse
Authors: Pakeyangkoon Pornsri , Tuampoemsab Surakit , Sritapunya Thritima , Rattanapan Apaipan
Published: June 2014

The improvement in impact properties of wood plastic composite from acrylate-styrene-acrylonitrile (ASA) and bagasse was reported in this work. The effect of type and content of impact modifier by using styrene-butadiene-rubber (SBR) and ethylene-acrylic acid (EAA) as impact modifier on morphology and mechanical properties of wood plastic composite were investigated. Wood plastic composites, prepared from ASA and 50 phr of bagasse by varying amount of impact modifier (both SBR and EAA) from 0-40 wt% of ASA were prepared by melt-blending technique. All materials were mixed by using a two-roll-mill, shaped into sheets by a compression molding machine and specimens were cut with a cutting machine. Then, the obtained materials were characterized, including morphology, impact strength and flexural properties. From SEM micrographs showed that wood plastic composites with using SBR as impact modifier showed more compatible with ASA matrix than EAA. This is a consistency results with mechanical properties such as impact properties, which indicated that the impact strength was improved with increasing the amount of SBR from 0-40 wt% of ASA. However, wood plastic composite with EAA showed the reduction of impact strength. So, it could be demonstrated from this study that the most appropriate impact modifier for wood plastic composite from ASA and bagasse was styrene-butadiene-rubber.
Structural and Optical Properties of Nanocrystalline ZnO Powder by a Direct Thermal Decomposition Route Using Zinc Acetate Dihydrate
Authors: Kaewwiset Weeranuch , Srisuphang Tarinee , Keawsomrong Sasiprapa , Sutthana Sutthipoj , Sujinnapram Supphadate
Published: June 2014

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc acetate dihydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 300 °C. The precursors were calcined at different temperatures of 400, 500, and 600 °C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.
Antagonism of Natural Anti- and Pro-Oxidants in Synthetic Polyisoprene Rubber Vulcanizates
Authors: Tuampoemsab Surakit , Rattanapan Apaipan , Pakeyangkoon Pornsri
Published: June 2014

This research was to elucidate the antagonism of natural anti-and pro-oxidants in synthetic polyisoprene rubber (IR) grade 2200 as a model system. Alanine and linoleic acid was chosen as natural anti-and pro-oxidants, respectively. These two amino acids were directly added into the rubber by mixing in two-roll mill. Peroxide vulcanization and three types of the sulfur curing system, i.e., conventional vulcanization (C.V.), efficient vulcanization (E.V.) and semi-E.V. have been studied. Cure properties of the rubber compounds were characterized with moving die rheometer (MDR) at 150 and 170°C for sulfur and peroxide vulcanizing systems, respectively. The compounded rubbers were divided into two parts. The former was pressed on a hydraulic hot press machine and cut to a dumbbell specimen according to ASTM D412 type C. Then, the rubber specimens were subjecting to accelerate the thermal oxidative degradation at 100°C under air-circulating oven with various times. The deterioration of the aged rubber specimens was determined by tensile test. The latter was shaped and characterized by ozone resistance in accordance with ISO 1431/1. For tensile test, the results showed that only the C.V. system of the sulfur cure, the tensile stress at 200% strain of IR comprised alanine and linoleic acid with the ratio of 1:1 was higher predominantly than that of the cured IR control. In addition, the peroxide cured IR mixed with alanine and linoleic acid cannot be passed the heat aging for 96 h. For the ozone resistance, the results exhibited that all specimens appeared uncountable number of crack but only the IR cured by peroxide presented the length of crack less than 1 mm (C-3). It might be concluded from the experiment that anti-oxidative activity of the alanine plays a vital role in the rubber vulcanizate only for C.V. system. However, the existing of both alanine and linoleic acid in the sulfur cured IR was not outstandingly changed for the ozone resistance but not that for the peroxide cured IR.
Effects of YMnO3 Addition on Phase Structure, Microstructure and Electrical Properties of (Na0.515K0.485)0.94Li0.06(Nb0.8Ta0.2)O3 Lead-Free Ceramics
Authors: Bomlai Pornsuda
Published: June 2014

The (1-x)[(Na0.515K0.485)0.94Li0.06(Nb0.8Ta0.2)O3]-xYMnO3 (x = 0, 0.005, 0.01, 0.015 and 0.02) lead-free ceramics were synthesized by solid-state reaction sintering method. It was found that the addition of YMnO3 affected on the grain size, phase structure and electrical properties of (Na0.515K0.485)0.94Li0.06(Nb0.8Ta0.2)O3 ceramics. The grain size decreased with increasing YMnO3 content (x ≥ 0.01) and led to poor densification. The ceramic doped with 0.5 mol% YMnO3 showed good electrical properties such as d33 = 195 pC/N, kp = 43.9 %, Tc = 292 °C, TO−T = 35 °C, εr = 820 and rather low dielectric dissipation factor = 2.1%. This indicates that 0.5 mol% YMnO3 -doped (Na0.515K0.485)0.94Li0.06(Nb0.8Ta0.2)O3 piezoceramic is an alternative lead-free piezoelectric material for the development of piezoelectric devices working at high temperature.
The Photoluminescence, Optical Absorption and Physical Properties of Dy3+ Ions in Li2O-La2O3-B2O3 Glass System
Authors: Wantana Nuanthip , Kim Hong Joo , Chamlek Onanong , Kaewkhao Jakrapong , Chanthima Natthakridta
Published: June 2014

The lithium lanthanum borate glasses doped with Dy2O3 were prepared by the melt quenching technique. The Dy2O3 doped concentration has been increased and substituted B2O3 from 0.00 to 1.50 mol% in the glasses. The photoluminescence, optical absorption and physical properties of these glasses have been investigated in this work. The experimental results show that, the molar volume of glasses tended to increase with increasing of Dy2O3 concentration, but the density were not depending on the concentration of Dy2O3. The UV-Vis-NIR spectra, absorption bands at 451, 798, 894, 1085 1264 and 1676 nm have been observed. For Dy3+ doped glasses, emission bands centered at 483, 575 and 664 nm have been observed with 388 nm excitation wavelength. The emission spectra have shown the strongest band in the glasses with 0.50 mol% Dy2O3 concentration.
Angular and Intensity Distributions on Multiple Scattering of 662 keV Gamma Photons in Aluminium
Authors: Siengsanoh Kittipong , CHEWPRADITKUL WEERAPONG , Limsuwan Pichet , Boonin Kitipun , Kaewkhao Jakrapong , Limkitjaroenporn Pruittipol
Published: June 2014

This work studied about the angular and intensity distributions on multiple scattering gamma energy 662 keV, obtained from 137Cs source. The gamma photons are incident on aluminium scatterer of varying thickness is studied experimentally in both the forward and backward hemispheres. The observed spectra recorded by a properly shielded NaI(Tl) scintillation detector. To extract the contribution of multiply scattered photons having same energy as in the singly scattered distribution from the measured spectra, a singly scattered distribution is reconstructed analytically. We observed that the number of multiply scattered photons also increases and saturates at a particular value of the scaterrer thickness and determined at different scattering angles.
Effect of the Mole Ratios of Zn2+:OH- on the Morphologies and Photocatalytic Activities of Ag/ZnO Photocatalysts
Authors: Amornpitoksuk Pongsaton , Suwanboon Sumetha
Published: June 2014

Ag/ZnO powders were synthesized through hydrolysis of Zn2+ in an alkaline solution at various mole ratios of Zn2+:OH- without any stabilizer. At a mole ratio of Zn2+:OH- = 1:1.5, the ZnO particles showed as bi-hexagonal prisms. At higher OH- concentrations, the shape became spherical and then finally transformed to an agglomeration of platelet like-shapes at mole ratios of Zn2+:OH- = 1:5. The photocatalytic activity was investigated through degradation of a methylene blue solution. Under irradiation from blacklight fluorescence tubes, ZnO prepared from Zn2+:OH- = 1:1.5 was the best photocatalyst compared with those prepared from different mole ratios of Zn2+:OH-. This could be due to a high area of hexagonal facets as represented by the (0002) plane. By varying the amount of added Ag between 1-5 mol%, the ZnO prepared from 3 mol% of Ag showed the highest efficiency for photocatalytic degradation of methylene blue and its activity was also better than for pure ZnO.
A Facile Fynthesis of ZnS Nanostructures via Liquid-Solid Reactions
Authors: Phoohinkong Weerachon , Sukonket Thitinat , Kitthawee Udomsak
Published: June 2014

Zinc sulfide (ZnS) nanostructures are important materials for many technologies such as sensors, infrared windows, transistors, LED displays, and solar cells. However, many methods of synthesizing ZnS nanostructures are complex and require expensive equipment. In this study, a liquid-solid chemical reaction without surfactant was used to synthesize ZnS at room temperature. In addition, commercial grade zinc oxide (ZnO) particles were used as a precursor. The effect of the addition of acids and inorganic salts were investigated. The products were characterized by field emission scanning electron microscopy (FESEM) coupled with energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The results show that the nanoparticles of ZnS were obtained in hydrochloric acid and acetic acid addition. The diameters were in the range of 10 to 20 nm and 50 to 100 nm, respectively. In the case of a sodium chloride salt addition, a ZnS structure was obtained with a particle size of approximately 5 nm and a flake-like morphology.
Fabrication of Tantalum Oxide Nanorods by DC Magnetron Sputtering with Glancing Angle Deposition
Authors: Plirdpring T. , Horprathum M. , Eiamchai P. , Limwichean S. , Chananonnawathorn C. , Boonpichayapha T. , Suriwong Tawat
Published: June 2014

This study investigates tantalum oxide (Ta2O5) nanorods prepared by the dc magnetron sputtering with the glancing angle deposition (GLAD) technique. Silicon (100) wafer and glass slides were used as the substrates. The effect of the glancing angle varying from 73-87°, on the structural and optical properties were investigated by field-emission scanning electron microscopy (FE-SEM), atomic force microscope (AFM) and spectrophotometry. The results show that the deposition rate and diameter of Ta2O5 nanorod films were decreased with the increase in the glancing angle. At the highest glancing angle of 87°, the prepared Ta2O5 nanorod yielded the highest porosity from the vertically aligned columnar structure, and were must suitable for many functional applications.
Physical Parameters for a Contact Binary AY Aquarius
Authors: Maithong Wiraporn , Kruea-In Chatchai , Rattanasoon Somsawat
Published: June 2014

The physical parameters study of contact binary system AY Aquarius, the observations were done in 12th September 2011 at The Cerro Tololo Inter-American Observatory (CTIO), Chile. The Prompt4 0.4 - meter Ritchey-Chretien reflecting telescope and CCD Apogee Alta 10241024 pixels with standard visual and red filters of UBV were used. The orbital period of the contact binary system is about 0.28199 days. The photometry was analyzed by MaxIm program and used Wilson-Devinney technique to calculate the physical properties.
The Study on Zero-Temperature Gap of Superconductor Having the Coexistence of SDW and CDW
Authors: Thongcham Kanphot , Udomsamuthirun Pongkaew
Published: June 2014

In the field of superconductivity the most interesting area is the studying of the mechanism of the high Tc superconductor (HTS). Understanding of this mechanism, we can raise the critical temperature (Tc). There are many proposals theoretical descriptions for HTS. We focus on the spin density wave (SDW) and charge density wave (CDW), the static wave of spin density and charge density arising from the nesting property of Fermi surface that were observed in the superconductor. The model Hamiltonian of superconductor having SDW and CDW coexistence was studied by Greens function method. The analytic expression of zero-temperature gap of superconductor with the coexistence of the SDW and CDW were derived. By varying the effective potential, the phase diagram of the SDW and CDW was constructed then the band structure and density of states (DOS) of coexistent phase were also studied.