bluuebunny/crossref_metadata_2025 huggingface dataset:
The Building of Marketing Decision Support System Based on Data Warehouse
Authors: Ji Zhi Gang
Published: September 2010

An outline of marketing decision supporting date warehouse system based on the existing databases is proposed. The application of data warehouse technique and multi-agent systems to modern marketing decision support system may assist supervisors of enterprise to make an analysis of strategic decision and to improve the competitive power of the enterprise. Finally, the developing tools and the implementation of the Web-enabled data warehouse were discussed.
Research on Fractal Dimension Calculating Method Based on Improved Carpet Covered Algorithm
Authors: Wang Wei , Hong Jun , Qu Jue , Han Hua Ting , Zou Zhi Gang
Published: September 2010

This paper has researched and analyzed on the fractal dimension calculating method and selected Peleg Carpet Covered algorithm which is fit for fractal physiognomy analysis to research. Aiming at the shortage of Peleg Carpet Covered algorithm, an improved Carpet Covered algorithm is proposed. By experiment, the performance of original algorithm and improved algorithm is compared and validated, and the results show that improved algorithm has improved the calculating accuracy and texture-differentiating ability. Applying this algorithm to fractal topography creating can make the fractal topography model be alike to genuine physiognomy.
An Improved Viscous-Spring Artificial Boundary Model
Authors: Chen Jian Yun , Xu Qiang , Li Jing
Published: September 2010

A new artificial boundary model is proposed based on conventional viscous-spring artificial boundary model. Firstly, the stress formula on artificial boundary are derived based on the wave propagation theory and the new artificial boundary model is constructed by adding the nodal force to conventional viscous-spring on the boundary of finite field, which could include the effect of lateral boundary displacement. And then the values of the stiffness, the damp and nodal force are deduced based on stress wave theory. Finally, a numerical example is given to verify the proposed model. Compared with viscous-spring artificial boundary, this proposed artificial boundary model possesses the merits of same efficiency and conciseness, but higher precision than conventional viscous-spring artificial model.
Influences of an Initial Micro Gap on Wave Transmission
Authors: Chen Xiao Yun , Yu Gui Lan
Published: September 2010

The propagation of elastic waves through a micro gap considering frictional contact is investigated in the present paper. Using the Fourier analysis technique and corrective solution superposition method, the problem is solved analytically. Special examples for identical materials are discussed in detail. The results show that the initial gap width has significant influences on the harmonics and energy partition and their relations may be effective on non-destructive evaluation of a pre-existing gap.
The Disposal of EEG De-Noising by a Wavelet New Threshold
Authors: Yu Lan Lan , Li Su Ling
Published: September 2010

The EEG signal is one of mini-voltage. In order to improve the performance of EEG and increase the measure efficiency, we must eliminate the noise in EEG. Wavelet threshold de-nosing techniques provide a new way to reduce noise in EEG. This paper proposes a wavelet new threshold de-noising function based on the study of the disadvantages of the hard threshold function and the soft threshold function. The simulation results show that the wavelet new threshold function is able to eliminate the noise effectively which can not only save the smooth effect of the soft threshold function but save the numerical value advantage of the hard threshold function.
Research on the Pretension of the NGW Reducer Tumbler Bearing
Authors: Zhao Hong Zhi , Ma Lin , Li Wei
Published: September 2010

The pretension of the central gear floating NGW planetary gear reducer tumbler bearing is studied. The relative displacements of the inner and outer rings of the tumbler bearing are analyzed according to the light, medium and heavy pretension loads. The tumbler bearing is tested in the different pretension loads. In some operating conditions such as constant power, constant rotating speed and constant torque, etc., the transmission efficiency, vibration and temperature of the reducer are tested and analyzed and the dynamic characteristic curve is obtained. According to the test curve, the principles of choosing the pretension loads of the tumbler bearing are presented. The experiment of this paper is also of reference value for studying the pretension of the other types of reducer bearings.
Safety Requirements Model-Based Safety Test Automation of Train Control System of High Speed Railway in China
Authors: Yu Gang , Xu Zhong Wei
Published: September 2010

Train control system is a safety-critical system, which requires a thorough safety testing before they are deployed. But the traditional technology of test automation is not sound for safety test of safety-critical software system because of its just aiming at the system functional requirements. Focusing on the safety requirements, this paper addresses a new method to perform safety test of safety-critical system based on safety requirement by using model-based test. The method presents safety automata to express safety properties in term of safety requirements and extract safety model from the safety requirements. It also provides a new technique for automatic generation of safety test case suite. By using the method, we have designed an automatic testing framework and developed an automatic testing platform, which has been applied to standard testing the product of train control system in term of the requirements of Ministry of railways in china, and implement effectively the functional and safety test of the product of train control system in china.
Design of A GUI Tool for the Prediction of Building Energy Performance
Authors: Yan Cheng Wen , Yao Jian , Xu Jin
Published: September 2010

In the present study a GUI tool for the prediction of building energy performance based on a three-layered BP neural network and MATLAB was developed. The inputs for this tool are the 18 building envelope parameters. The outputs are building heating, cooling and total energy consumptions and the energy saving rate. Compared with the complicated mathematical equations, this tool provides a very easy and effective method for students to learn the effects of building envelope performance parameters on the building energy performance. Thus, this tool can be used in building physics and building energy efficiency courses for the design of energy efficient building.
Controlled Five-Bar Mechanism Optimization Based on Two-Stage Synthesis Method
Authors: Yang Jin Tang , Kong Jian Yi , Li Gong Fa , Li Yao
Published: September 2010

This text has put forward the basic conception of visual angle, inside the track and outside the track. According to characteristic of controlled five-bar mechanism that can realize track of many points accurately, optimization model of controlled mechanism that can accurately realize track of many points was built. The method of generalized inverse based on windows solves optimal solution to displacement, speed, and acceleration of compensation movement and respond frequency as goal function. The instance calculating indicates that this method is practical and feasible.
Study on one Special-Shaped Long-Span Arch Bridge Using Wind Tunnel Test
Authors: Xu Fu You , Wang H.L. , Zhang Zhe , Huang Cai Liang
Published: September 2010

Study on wind-resistant performance of one special-shaped long-span arch bridge is carried out using a full-bridge aeroelastic model with a scale of 1:66 in wind tunnel test. The tests on vortex-induced vibration (VIV for short), buffeting and aerodynamic stability of both bare arch and full-bridge are comprehensively conducted in smooth and turbulent flows with attack angle of -3º, 0º, 3º, and yaw angles ranging from 0º to 180º with a step of 15º. The results show that the first-order symmetric VIV of vertical bending appears on the bare arch in smooth flow with attack angle of -3º, 0º, 3º, and yaw angle of 0º, 5º. The maximum amplitude of VIV at 1/4 section of the bare arch is close to 30cm, higher than the corresponding value at the crown section. No stable VIV is observed on full-bridge model tests in both smooth and turbulent flows. For full-bridge model in turbulent flows, both means and standard deviations of girder torsional displacement at 1/2 and 1/4 sections are very small, which prove that the bridge integral torsional stiffness is significantly improved due to the 3-D cable-support system. The bridge possesses good aerodynamic stability for both bare arch and full-bridge service states.
Comparative Analysis on Aerostatic Coefficients of Bridge Deck Based on Wind Tunnel Test
Authors: Xu Fu You , Li Bin Bin , Huang Cai Liang , Zhang Zhe
Published: September 2010

A comprehensive study of force measurement test in wind tunnel is conducted for the streamlined deck model of Dalian Cross-sea Bridge scheme. The factors, including stacking load in erection, vehicles arrangement, central slot and so on, are analyzed in terms of the influence of the three-component coefficient in the way of microscopic mechanism. The stall angles under different working conditions are also investigated. The results show that stacking loads and vehicle arrangement barely have any impact on the three-component coefficient, which can be neglected approximately; lift and pitching coefficients decrease for the slotted deck, and the slot width has little influence on the aerostatic coefficients; bridge railing, stacking loads and vehicles change the flow separation and re-attachment around the deck, increasing the turbulence intensity, leading to the fluctuation of stall angles.
Research on the Force on the Plunger and the Roller of the Static Pressure Supporting Cylinder Pair
Authors: Xu Wen Qin , Zhou Bai Qing
Published: September 2010

A new radial plunger pump is given here, which is installed with a roller between the plunger and the stator. When in working order, the roller is purely rolling on the inner face of the stator, reducing the friction force and effectively avoiding the combustion of friction pair. The force on the roller and the plunger of the static pressure supporting cylinder pair are studied here and some theoretical evidences are provided for developing new radial-plunger pumps of high speed, high efficiency, and long lifetime.
Numerical Simulation of Oscillating Flows over a Circular Cylinder
Authors: Li Tian , Zhang Ji Ye , Zhang Wei Hua
Published: September 2010

Numerical Simulation of oscillating flow over a circular cylinder is calculated when the Reynolds number is 100. The space-time finite element method is used to solving the two-dimensional incompressible Navier-Stokes equations. Considering the oscillating flow over a variation of perturbation amplitudes and frequency ratios, the trends of lift coefficient with amplitude and frequency ratio are compared respectively. Besides, the FFT of the lift coefficient curves are analyzed. There is a suddenly change in main frequency and second frequency when A=0.1. The excited frequencies of lift coefficient are discussed, which could be the combination of vortex shedding natural frequency and perturbation frequency, such as |fe－f0|, fe, 2fe－f0, fe＋f0, 2fe＋f0, etc.
Virtual Five-Axis Milling of Free-Form Surface-Part I: Process Modeling
Authors: Zhang Li Qiang , Yan Ye Cui
Published: September 2010

In free-form surface machining, it is essential to optimize the feedrate in order to improve the machining efficiency. This work is the first of a two part paper on cutting force prediction and feedrate optimization for five-axis milling. Conservative cutting parameters have been mostly used since there was a lack of physical models and optimization tools. Part and tool deflections under high cutting forces may result in poor part quality. The extracted cutter workpiece engagements are used as input to a force prediction model. The predicted cutting forces are shown to be in reasonable agreement with those collection during a roughing operation on a dual blades part.
Plasma Assisted Deposition Technology of Optical Coating
Authors: Rong Xiao Hong , Li Chun Xia , Zhang Xiao Yan , Wang Yu Mei , Wang Wen Liang
Published: September 2010

Plasma assisted deposition technology with an advanced plasma source and its application in the field of optical coating fabrication are investigated. In this paper, MgF2, Al2O3 and TiO2 single layer films are prepared by this technology, and the measure results show that they all have good optical parameter.
Anti-Plane Moving Crack in Functionally-Graded Material
Authors: Liu Qi
Published: September 2010

In this paper the anti-plane moving crack in a functionally-graded material is studied by the analytical method. First the governing equations for a functionally-graded material are obtained using a Fourier cosine integral transform. Then the dual integral equations for moving crack are established according to the mixed boundary value conditions. It is shown that the dual integral equations can be reduced to the Fredholm integral equation of the second kind. Numerical results shown in the present paper indicate that the non-homogeneity of material has an important influence on the dynamic stress intensity factor.
Numerical Simulation and Research of Pool Fire Suppressed by Water Mist in the Engineroom of a Ship
Authors: Zhao Jian He , Gao Ye , Wu Hong Mei
Published: September 2010

Ship engineroom fire is one of the most common and serious disasters in shipwrecks. It has become a hotspot of research to use water mist system to extinguish engineroom fire efficiently in the ship fire fighting field. In this paper, using Fluent to simulate water mist suppressing engineroom fire on the conditions of different fire scales, droplet diameters, spray cone angles and spray pressures. Research indicates that: large scale fires are more easily suppressed than small scale fires by water mist in the enclosure engineroom; the droplets of water mist should be neither too big nor too small, or else it would go against fire fighting. It is pointed out that the droplets should be in the range of 200 μm to 400 μm; the smaller cone angle nozzle can guarantee a high flame cooling effect; the increase of spray pressure can enhance the flame cooling effect, but probably of only marginal help in reducing the oxygen content.
Synthesis and Characterization of Novel Segmented Castable Polyurethanes Based on 2,4-TDI and 3,5-DMTDA
Authors: Chen Xiao Dong , Ma Tie Jun , Zhang Hai , Chen Rong Sheng
Published: September 2010

A series of three castable polyurethane elastomers were prepared from 2,4- toluene diisocyanate (TDI) and 3,5-dimethyl-thioltoluenediamine (DMTDA) chain extender, with polyethylene adipate (PEA), polyoxytetramethylene glycol (PTMG) and polycaprolactone (PCL) soft segments. The polyol molecular weight employed was 2000g/mol. The polyurethane elastomers were characterized by an electronmechanical universal testing machine, a LX-A Shore durometer and a Dynamic Mechanical analyzer (DMA). In addition, fractured surface of the polyurethane elastomers was investigated by a field emission scanning electron microscopy (FE-SEM). The test results showed PCL based elastomer exhibits the excellent tear and stress-strain properties that polyester based elastomers offer, while retaining superior resilience similar to polyether based elastomers. The static and dynamic properties of PCL based elastomer were more suitable for dynamic applications. SEM micrographs of all polyurethane samples indicated the existing of microphase separation structure. Particles of the dispersed phase formed by hard phase and crystalline part of the soft phase grow bigger with increasing crystallinity of the soft segments. The hard domains are irregular shapes and with size of a few micrometers.
A Rod-Explosive Technique for Testing Structural Responses Induced by X-Ray Blow-Off Impulses
Authors: Mao Yong Jian , Deng Hong Jian , Li Yu Long , He Rong Jian , Xiao Hong Wei , Yue Xiao Hong , Huang Hai Ying , Zhou Qing
Published: September 2010

When a structure is irradiated by a pulsed cold X-ray with high energy density, the instantaneous deposition of energy will induce melting, vaporization, and sublimation of the outer layer of material(s). As a result, the material(s) will blow off and hence lead to a so-called blow-off impulse. This kind of impulsive load will cause high-level structural responses. In order to investigate the effects, various test simulation techniques, such as the light-initiated high explosive (LIHE) technique, the spray lead at target (SPLAT) technique and the sheet-explosive technique, were developed due to the lack of proper X-ray sources. This paper presents a rod-explosive technique developed from the sheet-explosive technique. In this technique, the main property of the explosive, i.e. the specific impulse, is determined by using a pendulum test facility. The simulation load (equivalent to the cosine-distributed specific impulse on a conical shell induced by X-ray) is designed by load discretization and impulse equivalence. Numerical simulations of structural responses to both X-ray loads and rod-explosive loads were performed for validating the test simulation technique. An application example of testing a complex structure is briefly given in the end. The rod-explosive technique has the features of low costs and rather high fidelities. It provides a new approach for testing the structural responses induced by X-ray blow-off impulses.
The Design and Performance Analysis of Multi-Axle Dynamic Steering System
Authors: Wang Shu Feng , Zhang Jun You
Published: September 2010

In order to improve vehicle steering performance, Multi-axle dynamic steering technology is put forward. Because of simple and low cost, the mechanical dynamic steering mechanism is suitable for heavy vehicle. In order to design ideal steering mechanism, the principle of dynamic steering mechanism was analyzed. Based on theories of multi-axle dynamic steering and vehicle dynamic, the steering angle relationships of different axles were analyzed. Taken a vehicle as an example, the corresponding steering mechanism was designed. Full vehicle model was established and handling stability performance was simulated. The results show that the mechanical dynamic steering vehicle can effectively improve vehicle agility performance at low speed and stability at high speed.
Frequency Band Energy Statistics Method and the Applications in Monitoring the Work Conditions for Mechanical Equipments
Authors: Yuan Yun Long , Yuan Chao Yong , Yang Chao Zhen
Published: September 2010

A new manner, named frequency band energy statistics method, has been proposed for the analysis of the spectra from the vibration signals. The recorded vibration signals were first divided into multi-segments. Then each segment was calculated via the FFT transformation and 1/3 octave spectrum to obtained the characteristics of energy distribution, by making the histogram maps of the obtained features of the frequency energies. Consequently, we can monitor the work conditions and fault diagnosis for the mechanical equipments by the compared analysis of the corresponding histogram maps of equipments with normal and abnormal work conditions. The results show that present method exhibits a very strong sensitivity to the changes of vibration signal, leading to the fine detection of the minor changes form the equipment work conditions. Current work might provide a novel and facile method for definitely monitoring the work conditions and fault diagnosis of the mechanical equipments.
Signal Collection and Analysis on CO2 Arc Welding Based on DSP
Authors: Dai Wen Jin , Chen Xiang Jie
Published: September 2010

On the base for TMS320F2407DSDSP, it can collect the electricity signal from the CO2 arc welding, and pick–up the character parameters for the frequency distributing in the short circuit time and arc welding time. It realizes the real-time inspection by the way for analyzing the dynamic current and voltage, U-I graphic and the character parameter during the welding.
Catalytic Properties of Ni-Mo Carbide and Nitride Phases Supported on SBA-15 and -16 in the Hydrodesulfurization of DBT
Authors: Aguillón-Martínez Edgar Caleb , Melo-Banda José Aarón , Guevara L.A. , Reyes T.A. , Ramos Galván C.E. , Silva R.R. , Domínguez J.M.
Published: September 2010

In this paper, the incorporation of carbide and nitride phases supported on mesoporous materials like SBA type is described in order to obtain a better material than commercial catalysts (NiMoS/Al2O3, Sg=269 m2.gr-1) specifically in the HDS of dibenzothiophene. The XRD patterns exhibit the presence of carbide and nitride phases in each series, respectively. In the nitride materials, the presence of oxide phases was more evident than in the carbide catalysts. The principal product was biphenyl (BF) for all the analyzed series. This behavior suggests that the DBT desulphurization pathway for the carbide materials was similar to that of sulfide catalysts. Bicyclohexyl (BCH) was analyzed as a product, and cyclohexylbenzene traces (CHB) were determined in a single catalyst (NiMoC-2%P/SBA-16). This was attributed to the hydrogenation character of carbide catalyst reported previously.
Effect of Hydrothermal Conditions on Isomerization Activity of Pt/SO42--ZrO2
Authors: Zhang Juan Juan , Song Yue Qin , Zhou Xiao Long , Li Cheng Lie , Wang Jin An , Xu Long Ya
Published: September 2010

Pt/SO42--ZrO2 catalysts (PSZ) were prepared by using a series of hydrous zirconia as support synthesized via a hydrothermal method. The catalytic performances of these catalysts were evaluated in the n-hexane isomerization in a fixed bed reactor. The crystalline structure, acidity, reduction properties, textural texture, and sulfur content were characterized by XRD, NH3-TPD, H2-TPR, N2 adsorption and thermal analysis. The experimental results indicated that the hydrothermal ageing of zirconium hydroxide led to great changes in the crystalline structure of hydrous zirconia support, sulfur content, and the acidity of PSZ. The abundant strong acid sites and high sulfur content were essential but insufficient to achieve a PSZ catalyst with high isomerization activity. Too weak or too strong interaction between sulfur species and zirconia in the catalysts was unfavorable to the isomerization reaction. The presence of considerable sulfate species interacting moderately with zirconia was crucial to high isomerization activity.
Influences of Surface Chemistry on Dehydrogenation Kinetics of Ammonia Borane in Porous Carbon Scaffold
Authors: Sepehri Saghar , Batalla García Betzaida , Zhang Qi Feng , Cao Guo Zhong
Published: September 2010

Ammonia borane (AB) with high gravimetric hydrogen capacity is of great interest for storing hydrogen in solid form which is an important issue in the growing field of hydrogen technology. In this work the effects of surface chemistry on dehydrogenation kinetics of carbon cryogel (CC) – ammonia borane nanocomposites have been studied. Boron-modified, nitrogen-modified, and boron-nitrogen- modified CCs were used as scaffold for AB and dehydrogenation kinetics of CC-ABs was studied by means of differential scanning calorimetry (DSC) at multiple heating rates. The results demonstrated that AB incorporated inside the mesopores of CC modified with nitrogen and boron possesses lower activation energy with enhanced kinetics of dehydrogenation due to catalytic effects as compared to AB in unmodified CC under otherwise the same or similar conditions. In addition, the lowest activation energy was observed for boron-modified CC-AB that could be attributed to the destabilization of AB by surface interactions with B2O3 that may accelerate the dehydrogenation process.
Alkylation of Benzene with Propylene over H3PW12O40 Supported on MCM-41 and -48 Type Mesoporous Materials
Authors: Gómez-Ruiz M. , Melo-Banda José Aarón , Ramos Galván C.E. , López S.E. , Silva R.R. , Alamilla R.I. , Domínguez J.M.
Published: September 2010

The present work, the HPA Keggin structure was supported on four different MCM phase types (hexagonal, spherical, elliptical, and cubic); their catalytic properties were tested in the alkylation of benzene with propylene in order to produce cumene. In the reaction, parameters like propylene flow, reaction temperature, phase type, as well as WHSV-1, HPA, and Cs content in the best MCM phase support were studied. The results showed that the MCM-48 with (30 wt. % HPA) catalyst had the best behavior in catalytic activity, showing the higher conversion and selectivity toward cumene as the main product.
Hydrogen Production by Steam Reforming of Methanol over a Ag/ZnO One Dimensional Catalyst
Authors: Pérez-Hernández Raul , Gutiérrez-Martínez A. , Mayoral Alvaro , Leonard Deepak F. , Fernández-García Ma. E. , Mondragón-Galicia G. , Miki M. , José-Yacamán Miguel
Published: September 2010

One dimensional (1-D) and three dimensional (3-D) ZnO were growth by a hydrothermal method. ZnO 1-D was employed as a support for silver nanoparticles in order to design a new catalyst and used on the steam reforming of methanol (SRM) reaction for H2 production. The catalytic activity of the Ag/ZnO sample with low content of Ag showed better performance on the SRM reaction than on high silver loading catalyst. So, the sample with small Ag particle size showed best performance in methanol conversion than catalyst with big Ag particle size, this finding could be attributed to the high ZnO/Ag ratio. According to results of SEM and TEM techniques the catalytic activity: methanol conversion, H2 and low CO production observed on the Ag/ZnO 1-D catalyst occurs in the edge sites rather than the rim sites. The role of Ag is to accept the hydrogen to be released to the gas phase. In addition, the 1.5Ag/ZnO 1-D catalyst showed good stability during the reaction.
Studies on Cobalt-Based Catalyst to Synthesize Heavy Hydrocarbons
Authors: Li Chen , Wang Pei Li , Ying Wei Yong , Fang Ding Ye
Published: September 2010

With incipient impregnation method, cobalt-based catalysts were prepared. The effects of the ZrO2 modification of support and the addition of the second metal Ru on heavy hydrocarbon synthesis were investigated in a fixed-bed reactor. The results revealed that, in cobalt-based catalysts modified with ZrO2, cobalt species were presented in the form of Co3O4, Zr species were highly dispersed or amorphous on the surface of the catalysts. ZrO2 addition also increased the desorption amount of CO, which was correlative with the degree of reduction of cobalt species. When the catalysts modified with ZrO2, the strong interaction between Co species and γ-Al2O3 support was replaced by a weak interaction between Co species and ZrO2. The ZrO2 modification increased the amount of easily reducible Co species. It is noteworthy that addition of a small quantity of Ru promoted the reduction of cobalt species, which led to the reduction temperature decreasing. For the 15w%Co0.4w%Ru4.3w%ZrO2/γ-Al2O3, at a reaction condition as feed gas ratio n(H2):n(CO)=2.0, 483K, 1.5MPa and 800h-1, the conversion of CO was 76.98 %, the selectivity of C5+ 88.36 %, the chain growth probability 0.86, and as to 15.0%Co0.4%Ru/γ-Al2O3, the conversion of CO was 67.15%, the selectivity of C5+ 84.41% and the chain growth probability 0.84.
Synthesis and Photocatalytic Performance of Hierarchical Porous Titanium Phosphonate Hybrid Materials
Authors: Ma Tian Yi , Ren Tie Zhen , Yuan Zhong Yong
Published: September 2010

A hierarchical meso-/macroporous titanium phosphonate (TPPH) hybrid material was prepared via a simple surfactant-assisted process with the use of the precursor tetrabutyl titanate and 1-hydroxy ethylidene-1,1-diphosphonic acid. The prepared hybrid TPPH presented amorphous phase, exhibiting a hierarchical macroporous structure composed of mesopores with a pore size of 2.0 nm. The BET surface area is 256 m2/g. The hydroxyethylidene-bridged organophosphonate groups were homogeneously incorporated in the network of the hierarchical porous solid, as revealed by FT-IR, MAS NMR, XPS, and TGA measurements. The optical properties and photocatalytic activity of the hierarchical TPPH material were investigated in comparison with those of hierarchical porous titanium phosphate and pure mesoporous titania materials, showing superiority of the inorganic-organic hybrid framework, suggesting promising photocatalysts for wastewater cleanup.
A Study of Wear Characteristics of Superpolished Orthopaedic Implant Materials Using Ultra-Precision Polishing
Authors: Cheung Chi Fai , Lee Wing Bun , Charlton P. , To Suet
Published: September 2010

Ultra-precision polishing is an emerging technology for producing superfinishing surfaces with sub-micrometer form accuracy and surface finish in nanometer range. It has been applied in superpolishing the freeform bearing surfaces of orthopaedic implants. It is believe that the superfinished surfaces are capable of prolonging the life of the implants. In this paper, an experimental investigation of ultra-precision polishing of orthopaedic implants and the study of the wear characteristics of the superfinished surfaces using a multi-directional pin-on-plate wear test simulator are implemented. Tests were carried out over 3 million cycles using Zeeko IRP200 superfinished cobalt chrome pins articulating against cross-linked UHMWPE plates. The results were compared to that of manually polished pins articulated against the same UHMWPE material. The results show that the Zeeko IRP200 polished pins produced better wear performance that that of the manually polished pins.
Advanced Lapping and Polishing Methods for Planarizing a Single-Crystal 4H-Sic Utilizing Fe Abrasive Particles
Authors: Kubota Akihisa , Yoshimura Masahiko , Watayo Takashi , Nakanishi Yoshitaka , Touge Mutsumi
Published: September 2010

We have developed advanced lapping and polishing methods for silicon carbide (SiC) substrates using an Fe abrasive particles and hydrogen peroxide (H2O2) solution. In this method, a SiC surface is oxidized by hydroxyl radicals (OH*), which was generated by Fe catalyst reactions, and the oxide layer on the SiC is mechanically and/or chemically removed by Fe abrasive particles and solution　[1-4]. In this study, we applied this planarization method for lapping and polishing SiC surface, in which catalytically generated hydroxyl radicals were utilized to oxidize the surface of a SiC wafer. The processed surfaces were observed by optical interferometric microscope, Nomarski differential interference contrast. These observations showed that surface roughness and flatness of a SiC substrate were markedly improved and scratch-free SiC surface was obtained. These results provide useful information for preparing a high-efficiency and high-accuracy SiC substrate.
Study on Machining of Cracking Notches for Automotive Connecting Rod Using WEDM
Authors: Tang Yong Jun , Li Yuan Bo , Zhang Yong Jun , Zhou Chun Qiang
Published: September 2010

In order to resolve the problem of connecting rod notches machining, a new process of WEDM (Wire Electric Discharge Machine) has been presented, and it is greatly possible that expensive laser process can be replaced by WEDM in virtue of its unique advantages. Firstly, process parameters of notch have been analyzed, and project of machining notch using WEDM has been introduced, including measures to achieve good-quality notch. The relationship between cutting speed and power supply parameters has been investigated, and it is discovered that micro-crackle on bottom of notch are greatly effect to fracture splitting process, also new idea of active controlling micro-crackle has been presented. Finally, fracture splitting machining has been carried out. The cost and entrance standard of fracture splitting process are greatly dropped owing to new breakthrough of machining notch using WEDM.
Practical Design for Energy-Saving EDM Supply System
Authors: Wang Yu Kui , Wang Zhen Long , Song Bo Yan , Hu Fu Qiang
Published: September 2010

In this paper a kind of architecture for an energy-saving EDM supply composed of three serial stages in the topology and its practical design are discussed. Various special controllers and its assisted circuits are introduced in the each of the three serial stages. The PFC controller UC3854 placed on the front stage provides satisfactory input power factor of the system. The PWM controller UC3875 mounted on the middle stage realize the closed control of the current of the inductance limiting machining current. An embedded controller PIC16F877 on the final stage is chosen to setting such machining variables as peak current, discharge duration and pulse interval. The communication with host PC is also realized by the same embedded controller. The architecture based on model of multi-controller parallel working guarantees capacity of the system real-time process. The prototype of the energy-saving EDM pulse supply using MOSFET power device is developed. A lot of experiments have demonstrated the feasibility and stability of the practical design.
Study of Dynamic Magnetic Field Assisted Finishing for Metal Mold Using Magnetic Compound Fluid (MCF)
Authors: Sato Takashi , Wu Yong Bo , Lin Wei Min , Shimada Kunio
Published: September 2010

The finishing process of a metal mold depends on the hand work of experts by using a whetstone tool in many cases. This is because it is difficult to treat the three-dimensional configuration, such as free-form surfaces and convex and concave configurations. To overcome this difficulty, we propose a dynamic magnetic field assisted finishing using magnetic compound fluid (MCF) for three-dimensional configurations. In this paper, we demonstrate the MCF slurry (MCF mixed abrasive and cellulose fiber in) under dynamic magnetic field shows the high form restoration and generates the high normal force compared to that under static magnetic field; resulting in shows the high finishing performance. Moreover, we compare and discuss the surface roughness and form accuracy under both static and dynamic magnetic fields against three-dimensional configuration made of high hardness non-ferrous mold steel HPM75, which is used for plastic injection mold.
A Study on Application of Making Porous Micro-Structural Aluminum Oxide Template by Anodic Aluminum Oxide Processing Technology in Cell Reproduction
Authors: Weng Yung Jin , Huang J.C. , Weng Yung Chun , Wong Y.C. , Liu Hsu Kang , Yang Sen Yeu
Published: September 2010

This study employed the Anodic Aluminum Oxide (AAO) method twice for AAO processing to prepare neatly-arranged aluminum oxide film micro nano porous structure, and conducted experiments by adjusting different condition parameters (current, voltage, and temperature). The experimental results showed that voltage would directly affect the pore space and surface roughness of the aluminum oxide film. In addition, after anodic treatment, the positive and negative surfaces demonstrated varying degrees of roughness under the same conditions. In this study, the experiment of surface roughness impact on cell proliferation demonstrated that cell proliferation was better when surface roughness was in the range of 0.4 nm < Ra < 1.2 nm.
Comparing Microgroove Array Forming with Micropyramid Array Forming in the Glass Molding Press
Authors: Zhou Tian Feng , Yan Ji Wang , Kuriyagawa Tsunemoto
Published: September 2010

This paper presents a glass molding press (GMP) method to fabricate microgroove array and micropyramid array on the glass plate by replicating the shape of the mold to the glass surface. The differences between microgroove forming and micropyramid forming were investigated by experiments and finite element method (FEM) simulations. Microgroove arrays and micropyramid arrays were generated on the flat glass plate in the GMP process by using an electroless-plated Nickel Phosphorus (Ni-P) mold, on which the microstructures are fabricated by micro cutting. Furthermore, FEM simulations were used to trace the stress distribution and the strain distribution during the glass deformation, which illustrates the glass material flow in the microgrooves and the micropyramids on the mold during pressing. By comparing the processes between microgroove forming and micropyramid forming, the differences between them observed in the experiments were explained by the simulation results. Finally, some techniques to improve the forming accuracy were proposed.
Design and Fabrication of Composite Solar Concentrator
Authors: Cheng Ying , Fang Feng Zhou , Zhang Xiao Dong , Hu Xiao Tang
Published: September 2010

The solar concentrator is the primary means of solving the contradiction between cost and photoelectric conversion efficiency. The design and fabrication of concentrator are the key techniques to accelerate the application of photovoltaic systems. A novel type of composite concentrator is designed, including two mirrors and one planar lens. The primary mirror focuses the sunlight on the secondary condenser, which is one multi-segmented cone mirror to produce homogenization on the solar cell. The selection strategy of structure parameters is analyzed by the numerical calculation methods. The concentration ratio and homogenization on the receiving surface are also obtained using the optical simulation method. The designed mirrors are fabricated by the ultra-precision turning method, and then assembled according to the location parameters designed. The proposed methods are proved to be satisfied with the solar application efficiently by the experiments.
Development of Bi-Layer Porosity Graded Ceramic Component
Authors: Ong Zi Yan Amanda , Zhang Su Xia , Li Tao , Li Qing Fa
Published: September 2010

Porosity graded composite component can be found in applications such as fuel cells, filters or bio-scaffolds or implants. In this paper, two materials powder injection moulding is applied to manufacture bi-layer ceramic components with graded porosity. Ceramic spinel, AR7820, is selected to form the denser layer while the porous layer consists of AR7820 with starch or graphite pore former and spinel AR7845. The pore formers have proven to be feasible in producing porous structure in individual component. Porous layer with graphite and starch pore formers sintered at 1600oC has a porosity of 36% and 37% respectively. However delamination of the layers occurs when they are shaped together with AR7820. This is because the pore formers altered the shrinkage behaviour of the base material which resulted in discrepancies in the shrinkages between the two layers. On the other hand, defect free porosity graded composite component with good and continuous bonding between the layers was obtained when AR7845 is combined with AR7820.
Research on Hygrothermal Aging of Dynamic Injection Molded Polypropylene Products
Authors: Liu Bin , Wu Sheng Jin , Liu Qing Hui , Qu Jin Ping
Published: September 2010

The polypropylene products are injection molded by the dynamic injection molding machine. The performance characteristics of polypropylene products under steady and dynamic injection molding are gained by the DSC indicating methods. Accelerated aging test with hygrothermal test chamber (the aging temperature is 90°C, and the humidity is 95%) is conducted in the study. The regularity for impact strength property of polypropylene is studied during the test in contrast. The change of carbonyl content in the polypropylene products is analyzed both before and after aging by FTIR. The results show that the dynamic injection molding could significantly improve the anti-hygrothermal aging properties of the polypropylene products.
FEM-Based Modeling of Dynamic Recrystallization of AISI 52100 Steel Using Cellular Automaton Method
Authors: Wang Ke Lu , Fu M.W. , Lu Jian
Published: September 2010

The dynamic recrystallization (DRX) behavior in the isothermal hot compression of AISI 52100 steel was analyzed by using the phenomenological-based cellular automaton (CA) algorithm. The developed CA model was coded into DEFORM platform, which is a Finite Element Method (FEM)-based software for simulation of material deformation process. The developed CA-model can thus predict the nucleation and growth kinetics of dynamically recrystallized grains of the testing material in hot working process. Furthermore, the effects of the deformation temperature, true strain and strain rate on the microstructural evolution of the testing material were physically studied by using Gleeble-1500 thermo-mechanical simulator and the developed CA-model was verified by the experimental results. Through simulation and experiment, it is found that the results predicted by the CA-model have a good agreement with the experimental ones.
Hot-Embossing of Microstructures on Large Area of Polymers
Authors: Lin Wei , Chen Wen Jie , Kiew Choon Meng , Ng Chuen Leong , Luo Hong , Teo Chek Sing , Yang Gui Ling
Published: September 2010

This paper addresses the limitations of current hot embossing machines for mass production applications. It describes the features of a hot embossing machine in terms of machine design for handling large surfaces, embossing head for fast and precise temperature control, and the alignment mechanism for controlling the residual uniformity and planar offsets for producing microstructures uniformly on large area by means of step-and-repeat method. The developed machine demonstrated that microstructures of features size of up to 100µm could be replicated in 250s on PMMA sheet with an electroplated nickel stamp. The linear dimensions of the embossed features however were generally smaller than those in the stamp, which highlighted the importance of precision process control.
Precision Motion Control with Active Eddy Current Damper
Authors: Teo Chek Sing , Ong Chea Jack , Ho C.J. , Huang S. , Tan K.K.
Published: September 2010

This paper describes the design and proof of concept for an active eddy current damper which is integrated into a single-axis linear motor. Although developments on active eddy current damper are well documented, none has been implemented in a linear motor. The advantage of such a system is two-fold. Firstly, the relative motion between the magnets and the conducting sheet produces eddy currents resulting in an electromagnetic force opposing the direction of motion; which can be utilized to suppress vibrations. Secondly, it is possible to enhance the damping effect of the system; Due to environmental noise, it is normally not possible to increase the D coefficient in a PID controller as much as desirable. The damper is thus able to supplement this damping effect to improve settling time. Here, we will present the damper design as well as the preliminary experiment results for both vibration suppression and motion damping.
Development of Piezo Driven Inchworm Micro X-Y Stage and Hemispherical Tilting Positioner with Microscope Head
Authors: Aoyama Hisayuki , Chiba Hiroyuki , Takizawa Masato , Itami Youhei , Irie Yuuka , Hirata Shinnosuke
Published: September 2010

This paper deals with small piezo driven inchworm X-Y stage for a cell-manipulation in SEM chamber. Generally the electric noise from the moto causes the image destorsion in SEM operation. Thus the piezo driven inchworm small X-Y stage has been designed and fabricated as well as another tilting mechanism has been developed so that a micro pipettee can be implemented onto this tilting stage and manipulate such bio cell samples. Here we also developed a manipulation tool with micro force indicating system by using acoustic modulation technique since the microscopic operation in SEM without tactile information is difficult for the operator to control the tool precisely. On the other hand, a self-walking wafer inspection system is also described. The unique system is composed of the hemispherical manipulator and a self-walking piezo driven stage. This small walking mechanism can move on the glass plate that covers on the micro patterned plate. The hemispherical ball with microscope lens that can be rotated by the manner of stick-slip with three point contact piezo actuators is mounted on this self-walking stage so that the microscope lens can be focused onto the target sample to investigate the defect of micro patterns on the printed plate.
Surface Characterization with an Ionization Probe
Authors: Yang Chris , Zharin Anatoly , Danyluk Steven
Published: September 2010

This paper discusses the application of an ionizing source coupled with galvanic differences between metals in a measure of the work function difference between the metal surfaces. The electrical field generated from the contact potential difference (CPD) between two electrodes will cause the gaseous ions to discharge at both surfaces, creating a measurable current. The current depends on the surface size, spacing, and ionizing source power. One of the surfaces (probe) can vary in shape and size, and if inert, can be used to obtain the work function or surface potential of the second surface. The ionic current is proportional to ion mobility, ion generation rate, CPD, and the probe size, but inversely proportional to the spacing between the probe and the sample. It is found, as expected, that there is an approximate linear relationship between the ionization probe signal and the work function of the surfaces of metals.
Development of an On-Machine Machining Error Measurement and Compensation System for Micro Milling Process
Authors: Wang Shih Ming , Yu Han Jen , Yang Jih Pong , Chen Da Fan
Published: September 2010

To further enhance the accuracy of a micro milling process, an effective error measurement method and error compensation method are necessary. An on-machine vision-based error measurement method integrating image re-constructive technology, camera pixel correction, and model comparison algorithm to provide the capability of non-contact measurement for micro-machined workpiece error was developed. With use of Canny Edge Detection algorithm and camera pixel calibration, the edge of the contour of a machined workpiece can be identified and used to re-construct the actual shape of the workpiece. The actual shape will then be compared to the theoretical shape of the workpiece. To prove the feasibility of the proposed methods and system, experiments were conducted. The results have shown the success of enhacing machining accuracy for a micro milling process.
Electrical Conductivity and Flexural Strength of Graphite/Carbon Nanotubes/Epoxy Nanocomposites
Authors: Suherman Hendra , Sahari Jaafar , Sulong Abu Bakar , Royan R. Nishata
Published: September 2010

Carbon nanotubes (CNTs) have excellent mechanical and electrical properties. CNTs reported have excellent properties that can replace conventional conductive filler in advanced engineering applications. The polymer matrix was epoxy resin (EP).Conductive fillers were MWCNTs and synthetic graphite (G). Different variation of CNTs (0~10 wt. %) and graphite (60 ~ 67.5 wt. %) loading concentration were added into the epoxy resin. Dispersion of CNTs and G in epoxy resin were conducted by internal mixer with a Haake torque rheometer. The mixture of G/CNTs/EP was poured into the steel mold, and G/CNTs/EP nanocomposites had been fabricated through compression molding. The electrical conductivity of nanocomposites in term of variation of G and CNTs concentration were measured by the four point probe for in plane electrical conductivity. The results revealed that addition of G/CNTs and increasing curing temperature are an effective ways to produce high electrical conductive nanocomposites. Dispersion quality of CNTs and G in epoxy matrix were observed on the fractured surface by scanning electron microscopic.