bluuebunny/crossref_metadata_2025 huggingface dataset:
A General Modification Theory for Double-Enveloping Hourglass Worm Drives
Authors: Zhao Ya Ping , Wu Tian Chao
Published: August 2011

A universal modification theory is developed for all kinds of hourglass worm drives, no matter what shape the generating surface of the worm is. Based on the theory established, toroidal worm drives can be classified into two main categories: with singular points and without singular points. That is to say, the unmodified hourglass worm gearing is merely a special case of the modified one in essence. Furthermore, the meshing characteristics of a double-enveloping toroidal worm drive are entirely up to the situation of the solution of the meshing equation of the second envelope.
The Relationship between the Network Externalities of Complementary Modularity
Authors: Huang Zu Ying , Liu Xing
Published: August 2011

This paper adds to the growing literature on the vertically specialized collaboration of modularity firms by applying a model in which complement and core products collaborate with each other in a network situation. More specifically, it investigates the influence of the complement’s network strength on the equilibrium price and output of the core product. The results thus characterize the relationship between the complement’s and the core products’ network strength during collaboration.
Study of the Dynamics Coupling of Three-Axis Motion Simulator
Authors: Li Qiang , Xue Kai
Published: August 2011

An engineering computational method of major loads in three-axis motion simulator is presented. Simulation calculation of the motor output torque has been completed when three frames individually swinging, and individually rotating at a constant speed; the motor coupling torque was also computed when synchronously swinging, and synchronously rotating at a constant speed. The test experiment has been finished. According to the comparison of results from the simulation, the experiment and the engineering computation, a conclusion is drawn that the simulation results in ADAMS are helpful for selection of driving motor in design stage, because the engineering computation results without taken the coupling impact between three frames into consideration are not accurate where the coupling impact of torque in three frames leads to an increase in motor output torque when the three frames rotating synchronously.
The Experimental Research on the Sound Absorption Coefficient of Several Different Mytilaria Laosensis Veneering Boards
Authors: Su Chu Wang , Yuan Quan Ping , Huang Jing Da , Yang Kang
Published: August 2011

The composite acoustics board with pore-tank structure and variable cross section structure are made of Medium Density Fiberboard(MDF) as base material, Mytilaria laosensis sheet as veneer board, and sound absorption mat as the substructure material with the micro-perforation interlayer structure. The test was carried out to compare the absorption coefficient of Mytilaria laosensis sheet and nine samples by standing wave tube The test result shows that Mytilaria laosensis sheet has a low sound-absorbing performance itself, and its sound-absorption coefficient in all frequency ranges less than 0.3 and cannot be used as the sound-absorption board alone; The variable cross section structure sound-absorption board has a better performance than the pore-tank structure; When using the micro-perforation layer structure, the sound absorption board performs better and the sound absorption coefficient improves markedly in middle and low frequency scope.
The Experimental Study on Characteristics of Low-Temperature Grinding of Ceramic Hollow Ball Super-Hard Composite Abrasive
Authors: Cui Z.M. , Kong J.P. , Yang X.P. , Du Lei
Published: August 2011

Ceramic hollow ball Super hard composite abrasive has spherical hollow Mini-bore structure, This article introduced the structure of hollow spherical super hard abrasive, grinding model and the experimental investigations were conducted, It is found that the grinding wheel with hollow ball Super hard composite abrasive has more holes in the working layer of grinding wheel and can carrying more cooling fluid into the grinding area for heat exchanges, thus reducing the grinding temperature.
Performance of Laser Brazing Diamond Grinding Wheel in Face Grinding
Authors: Yang Zhi Bo , Zhang L.M. , Xu Jiu Hua , Zhao G.L.
Published: August 2011

A new technology kind of brazed monolayer cup diamond grinding wheel was developed via laser in an argon atmosphere. Grinding performances of this kind of brazed wheel in the surface grinding of the granites were studied. The experiment results show that the normal grinding forces and wear of diamond grits become higher with the increasing of the accumulated removal volume during grinding granites process. When continuous dry grinding was employed, the grits of the brazed diamond grinding wheel fail mainly in attired wear mode other than pull-out ones in conventional electroplated and sintered diamond tools, which indicates that the strong retention of brazing alloy to the diamond grits and longer service life of this kind of wheel.
Three-Dimensional Simulation of Wheel Topography
Authors: Feng Qiang , Wang Qian , Ren Cheng Zu
Published: August 2011

Simulation of wheel surface topography is one key aspect of modeling the grinding process. A three-dimensional wheel topography model not only makes the simulated wheel topography more close to the real situation, but also benefits evaluation of wheel machinability and wears condition. This paper presents a physical model for simulation of three-dimensional wheel surface topography. Wheel structural components, grain shape, angle distribution of cutting edges, and the binding materials are considered in the model. Feasibility of the model is indicated by the simulation examples.
Effect of Ultrasonic on Coating Performances of Electroplated Diamond Tools
Authors: Wang Y.G. , Lin Bin , Liu Y.H. , Yu Ai Bing
Published: August 2011

Electroplating experiments were carried out using a conventional Watts bath with the application of ultrasonic in order to improve the coating quality. The effects of ultrasonic power on coating comprehensive characteristics were studied. The microstructure, hardness and thickness of the coatings were observed and determined by a HXD-100TMC type microhardness tester. The coating corrosion resistance was examined through soaking in 36% hydrochloric acid. The adhesive strength of the coatings was tested with the method of heat-shock. The results showed that the properties of the coatings are improved basically with the increase of ultrasonic power. It’s considered the coatings have the best comprehensive performances when ultrasonic power is 200W, which provides a basis for the subsequent fabrication of ultrasonic electroplated diamond tools.
Research on the CAD Technology of Resin-Bonded Diamond Abrasive Tool Based on Quality Control
Authors: Liu Nan Bo , Wu Zhao Yun , Li G.Y. , Weng N.
Published: August 2011

In view of the problems of the computer aided design in the abrasive tool manufacturers, the manufacturing process flow of the resin-bonded diamond abrasive tool and the related factors affecting the quality were analyzed. The principle of CAD technology based on quality control was proposed. The key technologies of the abrasive tool CAD system based on quality control were put forward, including the computer aided formula design, the process flow design based on the parametric templates, the quality control technology based on the parameter constraints, etc. Based on these, the resin-bonded diamond abrasive tool CAD system based on quality control was developed. The development environment and implementation methods of the system were proposed.
Investigation on the Workpiece Surface Residual Stress in High Efficiency Deep Grinding with Ultra High Wheel Speeds
Authors: Jin Tan , Stephenson D.J. , Sheng X.M.
Published: August 2011

The residual stress on the ground surface of workpiece in high efficiency deep grinding (HEDG) has been investigated. It has been found that the mechanism in forming the ground surface residual stress in HEDG is much different to that in the conventional shallow cut grinding process. It is not a thermally dominant event as in most of the shallow cut grinding mode; it is instead driven by the combined effects of both the thermal and mechanical loadings. The compressive plastic deformation near the workpiece surface during grinding and the short contact time in the HEDG regime, makes it possible to generate compressive surface stresses even when the surface temperatures are above 700-800°C.
Comparative Research of Several Grinding Media Based on Electro-Magnetic Barrel Finishing Method
Authors: Yu Ke Qiang , Yan F. , Liao G.B. , Chen Yan
Published: August 2011

As the only known grinding media of magnetic barrel finishing, stainless steel pins are widely utilized to polish surfaces of some small workpieces. Through comparative research of several grinding media including pins as well as their compound, this paper introduces a new improved method by mixing pins with magnetic abrasive particles based on the electro-magnetic barrel finishing process. The experimental results prove its effectiveness.
Research on Surface Grinding and Polishing Process of Precise Hydraulic Couples
Authors: Wang W.H. , Teng L. , Zhao B.L. , Yang Q.Q. , Wang J.J. , Tong B.
Published: August 2011

Manufacturing of precise couples is the most important key technology for hydraulic products. The hydraulic characteristics are not only strongly correlated with their geometric elements, but also associated with the surface qualities of the couples, including surface roughness and surface texture, and which primarily influence the dead zone, lag rings and friction of the couples. In order to get better surface machining quality of the precise hydraulic couples, the process of surface grinding and polishing was researched. Through process test, the optimum parameters of grinding and polishing processing were found, which made the surface roughness achieved Ra 0.031μm.
Study of the on-Line Testing Method for the Abrasive Belt Follow-up Grinding of the Crankshaft Crankpin
Authors: Zhang L. , Huang Yun , Wang Y.J. , Zhang M.
Published: August 2011

In order to get the crankshaft crankpin’s surface shape errors and geometric dimension in real time, this paper presented an on-line follow-up tracing measurement method for measuring the roundness error and diameters of the crankshaft crankpin same time according with the characteristics of the crankshaft abrasive belt follow-up grinding process. After analyzing the movement control model of the follow-up tracing system, we obtained the constraint conditions which can fill the uniform sampling requirements of the sensor group. On this basis, we put forward the three-sensor follow-up tracing principle to separate the crankpin’s roundness error and systematic error from the actual measurement data. According to the principle of DFT, the fundamental equations of the three-sensor tracing principle for the roundness error separation were deduced in details. It is testified by experiments that: the roundness error source can be obtained by analyzing the original data, then we can compensate the errors through the feedback control system, so as to achieve the objective of improving the crankshaft crankpin’s roundness and the processing precision of the crankshaft crankpin.
Influence of Ultrasonic Assistance on Material Removal Mechanism of Hard and Brittle Materials Based on Single-Point Scratch
Authors: Jiao Feng , Zhao Bo
Published: August 2011

In order to deeply study the influence of ultrasonic assistance on material removal characteristics of hard and brittle materials, a series of ultrasonic assisted single-point scratch experiments have been carried out in this paper. Experimental results show that the assisted ultrasonic vibration is benefit to increase the critical cutting depth and enlarge the ductile regime of material removal. The main reason can be explained as the influences of blank cutting phenomenon, the decrease of the normal cutting force under the same depth of cut, the decrease of the material hardness under ultrasonic excitation and the shielding effect of lateral crack.
Influences of Grinding Parameters on Flexural Strength in the Grinding of Li-Spinel Ferrites with Electroplated Diamond Wheel
Authors: Sun L.P. , Wang Yu Guo , Yang Yang , Yu X.R. , Lin Bin
Published: August 2011

Through the odd factor grinding experiment of microwave ferrite, the residual flexural strength and surface roughness after grinding were measured in different grinding parameters(wheel speed, feed rate, cutting depth, wheel size). The surface of microwave ferrites was observed in high magnification through an optical microscope after grinding, in order to show the variation of surface roughness in different grinding parameters. The results showed that with the increase of the surface roughness, the residual flexural strength increased.
Research on the Ductile Chip Formation in Grinding of Brittle Materials
Authors: Peng Yun Feng , Liang Zhi Qiang , Wu Yong Bo , Guo Yin Biao , Jiang T. , Chen X.
Published: August 2011

A theoretical discussion has been presented for the ductile chip formation in grinding of brittle materials. The single abrasive grit was dealt with a top-rounded cutter removing material of varying undeformed chip thickness. The force model in the chip formation zone was established. The stress analysis showed that larger compressive stress and shear stress can be generated in the chip formation zone, which shields the growth of pre-existing flaws in the material by suppressing the stress intensity factor. When the stress intensify factor is smaller than fracture toughness and the resolved shear stress exceeds the critical flow stress of the material, the ductile chip is formed. Experiments of monocrystal silicon grinding were conducted. The results show that the thrust force is much larger than the cutting force, which ensures the larger compressive stress in the chip formation zone and the formation of ductile chip.
Research on Micro-Grinding Method and Surface Quality
Authors: Gong Ya Dong , Liu Yue Ming , Cheng Jun , Zhang J.F.
Published: August 2011

Grinding characteristics brought by the grinding speed reduction and geometrical model differences between micro-grinding and conventional grinding have been mainly researched. Influences which micro-grinding parameter and micro-grinding tool dimension parameter giving to grinding surface quality have been analyzed. The comparison experiment between micro-grinding and micro-milling has been carried out on the micro-machining test-bed developed by Northeast University. Wear of the grinding pin obtained from experiment is considered to provide the basis for the micro-machining system and fabricating of grinding pins.
Free-Software Development in Computer Science Education for Interface Representation in Casting Processes
Authors: López Joaquin
Published: August 2011

The aim of this work is to emphasize the advantages of the use of free software in computer science education for accurately representing complex interface shapes such as those that arise in casting processes during the filling of a mould cavity or during the solidification of the molten metal. A new scheme, based on free software, for reconstructing complex interface shapes in three dimensions has been specifically developed in order to facilitate its implementation by the students of a PhD course in the Polytechnic University of Cartagena (UPCT). In particular, a procedure to initialize the volume fraction occupied by a fluid body in computacional cells, and another to reconstruct the interface shape based on the initialized volume-fraction distribution, are proposed. Finally, different practical applications of this new scheme are presented.
The Metallurgy of Homogenisation
Authors: Rinderer Barbara
Published: August 2011

Homogenisation of aluminium alloys is the high temperature heat treatment (450-600 °C) performed after casting and consists of three distinct steps; heat-up, soak and cooldown. This review considers the metallurgical importance of homogenisation and how it impacts on the further processing and final properties of some aluminium alloys, with emphasis on homogenisation of extrusion billet. The introduction of continuous homogenisation has significantly improved the temperature uniformity of homogenisation allowing the soak time to be minimised. Batch homogenisation, however, provides flexibility in practices tailored for different aluminium alloys. Soft 6060 and 6063 alloys are best homogenised at a higher soak temperature than harder alloys such as 6061 and 6082. The homogenisation cooling rate can also impact on the behaviour of the billet during extrusion processing as well as affecting the final mechanical properties. An understanding of the microstructural changes occurring as a result of homogenisation allows the cast house to ensure that the billet processing meets the customer requirements.
Improving Casthouse Throughput Using Discrete-Event Modelling
Authors: Gunn Bruce , Frayman Yakov
Published: August 2011

The scheduling of metal to different casters in a casthouse is a complicated problem, attempting to find the balance between pot-line, crucible carrier, furnace and casting machine capacity. In this paper, a description will be given of a casthouse modelling system designed to test different scenarios for casthouse design and operation. Using discrete-event simulation, the casthouse model incorporates variable arrival times of metal carriers, crucible movements, caster operation and furnace conditions. Each part of the system is individually modelled and synchronised using a series of signals or semaphores. In addition, an easy to operate user interface allows for the modification of key parameters, and analysis of model output. Results from the model will be presented for a case study, which highlights the effect different parameters have on overall casthouse performance. The case study uses past production data from a casthouse to validate the model outputs, with the aim to perform a sensitivity analysis on the overall system. Along with metal preparation times and caster strip-down/setup, the temperature evolution within the furnaces is one key parameter in determining casthouse performance.
Sodium-Doped Hydroxyapatite Nanopowder through Sol-Gel Method: Synthesis and Characterization
Authors: Pusparini Erlani , Sopyan Iis , Hamdi Mohd. , Ramesh Singh
Published: August 2011

The nanocrystalline HA powders were produced through sol-gel method which employed calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] and diammonium hydrogen phosphate [(NH4)2HPO4] as calcium and phosphorous precursors. Sodium ion (Na+) is one of the trace elements found in biological apatite and believed to have important effect in its performance. The concentrations of sodium dopant were varied from 0 mol% until 15 mol% by using sodium nitrate (NaNO3) as the source of dopant. Characterization of nanopowders was investigated by using X-ray diffraction (XRD), Fourier transform infra red (FTIR) and Transmission Electron Microscope (TEM). XRD analysis revealed that there are no other phases exist in the synthesized powder, evinced single phase of HA and a trend shows an increase of cristallinity with increase of sodium dopant concentration. While the TEM images showed evidence that the particle sizes were bigger with the increasing sodium concentration, showing the effect of sodium dopant on the densification of the powder.
Influence of Shell Thickness on the Raman Properties of ZnO/ZnS Core/Shell Nanowires
Authors: Meng Xiu Qing , Wu Feng Min , Huang Shi Hua , Fang Yun Zhang , Li Jing Bo
Published: August 2011

Well aligned ZnO nanowire arrays are fabricated by a simple vapor phase transport process. Field-emission scanning electron microscopy shows the nanorods have a uniform length of about 1 um with diameters of 100 nm. After modified by ZnS, ZnO/ZnS core/shell nanowire arrays are formed and the thickness of ZnS layer increase with the increase of treatment time. X-ray diffraction analysis confirms that the as-synthesized ZnO nanorods are c-axis orientated, the modification of ZnS shell induces weak ZnS (100) diffraction peak for the treatment time of 180 min. The effects of shell thickness as a function of ZnS treatment time on the Raman scattering properties are studied. The results suggest that the coating of ZnS shell will change the Raman energy position and intensity of the ZnO nanowires, crystal lattice expansion and reconstruction of the ZnO/ZnS interface are responsible for the observed changes.
A Novel Ammonia Sensor Utilizing Cataluminescence on Nano-TiW3Cr2O14
Authors: Zhou Kao Wen , Zhang Zi Qiao , Xing Li Jing , Li Xin , Fu Chun Xue
Published: August 2011

A new sensor based on cataluminescence (CTL) produced on the surface of nanosized TiW3Cr2O14 was demonstrated for direct determination of ammonia in air. Trace ammonia was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 105°C to determine. The sensor showed high selectivity to ammonia at wavelength of 540 nm, satisfying activity at temperature of 275°C and good stability at air carrier flow rate of 115 ml/min. The linear range of CTL intensity versus concentration of ammonia was 1.0~50 mg/m3 (γ=0.9990), and the detection limit (3σ) was 0.5 mg/m3. The recovery of artificial sample was 97.45%—102.73% by this method. There was no response to benzene, SO2, CO and formaldehyde, and insignificant response to ethanol. This gas sensor allows on-line monitoring of ammonia in air.
Quasicontinuum Simulation of Uniaxial Tension of Single Crystal Copper Nanowire
Authors: Hu Xing Lei , Liang Ying Chun , Chen Jia Xuan , Pen Hong Min
Published: August 2011

Quasicontinuum simulations of tension test of single crystal copper nanowire are performed to analyze deformation mechanism of tension process and size effects of mechanical properties. New tension models of nanowire are constructed by using quasicontinuum method, which has combined molecular dynamics and finite element method. Tension processes of three different length nanowires without notches and those with notches are simulated. Yield strength and elastic modulus are calculated according to the obtained load-displacement curves. Finally, the results show that the mechanical properties of copper nanowire have obvious size effect and the notches have obvious influence on the mechanical properties.
The Role of Nanometer Silicon Dioxide in the Modification of Fluid Magnetic Abrasive
Authors: Li Wei Dong , Lv Ming , Zhang Hong
Published: August 2011

The fluid magnetic abrasive (FMA) is a new type of precision finishing abrasives which is a sort of suspended fluid composed by magnetic particles, nonmagnetic abrasive particles, surfactants in a non-magnetizable carrier liquid. This paper is to solve the contradiction of disperser stability by adding the surface active agent (dispersing agent), the nano- particles etc.
Spectroscopic Study of 2-Thiobarbituric Acid Modified Gold Nanoparticles
Authors: Du Juan , Xia Zhi Ning
Published: August 2011

Gold nanoparticles with a 13 nm diameter were synthesized and modified by a pH-sensitive, ionizable thiols acid, 2-thiobarbituric acid (TBA). After modification, the maximum absorbance wavelength shifted from 520 to 524 nm. Several effects were also investigated, including the pH, the salt and the metal ions effects.
The Synthesis of Nitrigen Doped Carbon Nanotube with Different Catalyst
Authors: Jin Hai Ying , Bing Nai Ci , Wang Ling Ling , Wang Li Jun
Published: August 2011

Bamboo-like nitrogen-doped carbon (CNX) nanotubes have been synthesized by chemical vapor deposition at high reaction temperature of 850°C. The diethylamine has been used as carbon source and Fe/SBA-15 and Ni/SBA-15 have been used as molecular sieve catalyst. Transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) observations showed that the diameter and the wall thickness of CNx nanotubes were increased with the change of catalyst from Fe/SBA-15 to Ni/SBA-15.
Effects of Different Substrates and Anneal Temperatures on the Nanoflakes Co(OH)2 Porous Films for Electrochemical Capacitance
Authors: Yu Zhan Jun , Guo Peng Fei , Yin Rong Can , Cui Yu Min
Published: August 2011

The nanoflakes Co(OH)2 porous films have been successfully electrodeposited on nickel foam and nickel foil substrates from cobalt nitrate dissolved in water–ethanol (1:1 volume ratio). Field emission scanning electron microscope (FESEM) studies present that the as-deposited films have an interlaced nanoflakes porous surface morphology. Various electrochemical test results show that the films on both substrates exhibit excellent electrochemical capacitive behavior due to the special nanoflakes porous structure. Furthermore, it is obvious that the nanoflakes films on nickel foam substrate have much higher specific capacitance (maximum: 2369 F/g) than that of the films on nickel foil substrate (maximum: 255 F/g). Electrochemical techniques are used to systematically study the effects of anneal temperatures on the capacitance of the films for nickel foam substrate. The specific capacitance as high as 2913 F/g is achieved for anneal at 100 °C, indicating its potential application as a low-cost, high-performance electrode material in electrochemical capacitors.
Structure Study of Nanocrystalline O-LiMnO2
Authors: Zhao Li Zhu , Chen Gang
Published: August 2011

The nanocrystalline orthorhombic LiMnO2 was successfully synthesized with the raw materials of MnO2, Mn (CH3COO)2 and LiOH by hydrothermal synthesis method, which has the properties of small size, less stacking faults and single phase. High resolution electron microscopy images show that along the b axis of the orthogonal LiMnO2, MnO6 and LiO6 octahedron arrange alternately and regularly. The orthorhombic LiMnO2 is proved to be p-type semiconductor by the Hall test. XPS tests indicate that the trivalent Mn in the o-LiMnO2 is in the high-spin state. And the magnetic study shows that there is reentrant spin glass behavior in o-LiMnO2. The contrast study of Raman spectroscopy and magnetic susceptibility shows that the characteristic mode softening of structural phase transition corresponds to the magnetic phase transition temperature, indicating a possible interaction between phonons and spin.
Preparation of Nano-TiO2/Fly Ash Beads Composite Material and Photocatalytic Properties
Authors: Guo Ling Kun , Lv Jun , Zhou Song , Wang Dong Mei , Zheng Zhi Xiang , Xu Guang Qing , Wu Yu Cheng
Published: August 2011

Using TiCl4 as the titanium source, urea as the precipitating agent, nano-TiO2/fly ash beads composite materials were prepared by hydrolysis-precipitation method. The materials were characterized by SEM and XRD methods. SEM observation shows that the surface of beads have been loaded a uniform TiO2 film. XRD results shows that TiO2 films have the main phases of anatase and rutile mixed crystal structure. The effect of surface activation process of fly ash beads on TiCl4 solution hydrolysis rate was studied. The influence of calcination temperature on the microstructure and properties of composite materials was also discussed. The photocatalytic properties of the prepared materials was measured by using UV-1800 uv-vis spectrophotometer. The results show that: The composite which calcined at 500°C has a grain size of 15nm, anatase phase content of 90%, shows the best photocatalytic effect. The degradation rate of methyl orange solution can reach 95% after 2 hours irradiation (300W, Mercury lamp). Repeated experiments show that the degradation rate of composite materials still reach 80% after being used for 5 times .
Research on Photocatalysis Properties of Nano TiO2/Mica Composite Material Prepared by the Method of Hydrolysis–Precipitation
Authors: Zhou Song , Wu Yu Cheng , Lv Jun , Guo Ling Kun , Wang Dong Mei , Xu Guang Qing , Zheng Zhi Xiang
Published: August 2011

Using muscovite as the carrier, TiCl4 as the source of titanium, urea as the precipitating agent, nano-TiO2/mica photocatalyst (TiO2/M) was prepared by the method of hydrolysis–precipitation. The as - prepared photocatalyst was characterized by XRD, SEM, EDS and UV methods. The methyl orange was used as contamination simulation to test the photocatalytic activity of the materials. The influence of the calcination temperature, radiation time and photocatalyst adding amount on photocatalytic activity of methyl orange were also discussed. The SEM and XRD results showed that nano-TiO2 particles had been evenly coated on the muscovite surface to be a dense layer. The results showed that: the phases of as – prepared materials were mixed crystalline of anatase and rutile after calcinating from 400°C to 700°C; After calcinating at 400°C for 2h, and adding concentration was 2g/L, the material had the best photocatalytic activity, the degradation rate of methyl orange reached 98% after radiation under 300W mercury lamp for 60min.
Research on the Structure of LiMnO2 Doped with Different Ni
Authors: Zhao Li Zhu , Zhang Jin Cheng , Xu Xiao Han , Chen Xiao Ying , Zhao Xiao Ming
Published: August 2011

In this paper, we synthesized LiMnO2 compounds doped with different amount of Ni by coprecipitation. The composition of the sample can be determined by ICP tests and energy loss spectroscopy. We found that the grain size decrease with more Ni doped .We found that the space group of the material is R-3m through XRD and Raman spectroscopy and with more Ni doped there is a blue shift in Raman spectroscopy. We can say that with more Ni doped, the material contains more Mn4 + through XPS analysis. But when Ni is doped excessively, there will be Ni3 + in the material. SEM analysis showed that corrosive effect of LiOH may have fatal effects on the electrochemical properties of the material.
Effect of Gamma-Irradiation towards Stress-Strain Curve of Single Die QFN Package
Authors: Wan Yusoff Wan Yusmawati , Jalar Azman , Othman Norinsan Kamil , Abdul Rahman Irman
Published: August 2011

The aim of the research was to establish the relationship between stress-strain behaviour of single die Quad Flat No lead (SDQFN) and degradation by gamma irradiation. The SDQFN was exposed to Cobalt-60 with different doses from 0.5 Gy, 1.5 Gy, 5.0 Gy, 10.0 Gy and 50.0 kGy. The three-point bending technique was used to measure the flexural stress and strain of the package behaviour relations. After exposing with gamma radiation, the result showed the decreasing in the strength of the package behaviour of irradiated SDQFN when increasing the dose of gamma irradiation. The highest gamma irradiation dose used in this work produced the highest change in stress-strain behaviour of irradiated SDQFN.
Effect of Measurement Temperature on Electroluminescence Properties of PET Films
Authors: Lin Jia Qi , Xia Ming Hui , Shi Jun Hui , Leng Jing , Chi Qing Guo
Published: August 2011

The Electroluminescence (EL) intensity and the spectrum of the of the PET films under different temperatures (77K, 296K, 353K) is tested, it is found that the pre-breakdown field under the low normal and high temperature of PET films is about 3.0MV/cm, 3.2MV/cm, 3.4MV/cm, respectively, and the formation of hot electron is not the main reason that cause aging and breakdown of PET films.
Stable Ti/IrO2 Anode with Iridium-Titanium Oxide Interlayers for O2 Evolution
Authors: Hu Jie Zhen , Deng Pei Chang , Wang Xiang Wen , Xu Hai Bo
Published: August 2011

Ti/IrOx–TiO2/IrO2 and Ti/IrO2–Ta2O5 electrodes were prepared using thermal decomposition procedure, respectively. The microstructure and electrochemical properties of the electrodes were studied with scanning electron microscope (SEM), X-ray diffraction (XRD), potentiodynamic polarization and accelerated life test. Experimental results showed that the Ti/IrOx–TiO2/IrO2 electrode has better electrocatalytic activity for oxygen evolution and higher stability, compared with the Ti/IrO2–Ta2O5 electrode under the same conditions. The high electrocatalytic activity of Ti/IrOx–TiO2/IrO2 electrode could be correlated with a large number of IrO2 particles on coating surface. The Ti/IrOx–TiO2/IrO2 electrode exhibits a three times longer service life than that of Ti/IrO2–Ta2O5, its superior stability was attributed to the IrOx–TiO2 interlayer, which contributes to form a metastable solid solution between IrOx and thin titanium oxide layer on titanium substrate during calcination and the improvement of the bonding of IrO2 layer with the substrate.
Elevated Temperature Mechanical Properties of Al-8.5Fe-1.3V-1.7Si/SiCP Composite Prepared by Multi-Layer Spray Deposition
Authors: He Yi Qiang , Qiao Bin , Feng Li Chao
Published: August 2011

Al-8.5Fe-1.3V-1.7Si/SiCP composite prepared by multi-layer spray deposition in different states were investigated. Ultimate tensile strengths of the composite sheets as-rolled tested at 315°C and 400°C are up to 300MPa and 186MPa respectively. The fine dispersoids and fine grains, and homogeneous SiC particles contribute to the excellent mechanical properties of the composite at elevated temperature. Specially, partial dissolution of SiC particles contributes to the stability of Al12(Fe,V)3Si phase.
Solidification Behavior of Undercooled Cu98Cr2 Alloys
Authors: Zhou Z. M. , Tang L. W. , Cao M.M. , Li X. P. , Luo J. , Zhou T. , Hu Y. , Zhan J.
Published: August 2011

The solidification behavior of undercooled Cu98Cr2 alloys was investigated under different rapid solidification methods. The results shown that whole lamellar (α+β) eutectics appeared in melt spun alloys for the sample undercooled into the coupled zone. The microstructure of arc melted Cu98Cr2 alloys consisted of primary β(Cr) particles distributes on α(Cu) matrix and (α+β) eutectics set in cellular α (Cu) phase. However, due to the different thickness and different solidification rate, the microstructure of splat quenched Cu98Cr2 alloys shown that only cellular supersaturated α solid solution occurred for thin flake and primary β(Cr) particles and (α+β) eutectics occurred for thicker flakes.
Measuring Subsurface Damage of the Ground Sample by Roughness along the Bevel
Authors: Wang Hai Rong , Sun Guo Liang , Guan Cheng , Chen Can , Jiang Zhuang De
Published: August 2011

This paper presents a method of measuring subsurface damage by roughness variation along the bevel surface, which is prepared by MRF taper polishing. Experiments for the ground K9 glass samples show that roughness varies obviously at the position where the subsurface damages go to disappear. Discussions indicate that the method is quantitative and simple for measuring subsurface damage.
The Preparation, Characterization and Application of the CNTs Modified Electrode
Authors: Cui Xue Mei , Ding Gui Fu , Wang Yan , Lu Wen Jing , Shen Hui
Published: August 2011

We propose a novel preparation technology of CNTs modified electrode. CNTs are mixed with polymer into homogenate by mechanical ball grinder; spin homogenate into composite film; solidify and polish composite film; chemical etch polymer partly from the surface of the composite film, in order to keep part of the CNTs be inserted in polyimide and the remainder outside of film, then CNTs modified electrode can be got. The morphologies of CNTs modified electrode are observed by field emission scanning electron microscopy (FESEM). The application of CNTs modified electrode in alum solution battery is demonstrated. Cyclic voltammetry of CNTs modified electrodes in V4+ solution is discussed.
Enterprise Multi–Project Selection Combination Restrained by Resources
Authors: Zhang Bo
Published: August 2011

Enterprises often develop more than one project at the same time, within relatively short time limit, and many elements involved , which puts a greate influence on the completion . In the present enterprise project management, there are phenomena that project relationship is chaotic, plans not implemented and resources competed . After introducing the difference between multi–project management and common project management, this paper analyses multi–project selection restrained by resources with genetic model, then provides a method of solving multi–project selection and combination, and finally proves the method has a greater practical significance with a case.
Vacuum Adhesive Bonding and Stress Isolation for MEMS Resonant Pressure Sensor Package
Authors: Li Yu Xin , Chen De Yong , Wang Jun Bo
Published: August 2011

This paper presents a method of low temperature adhesive bonding and stress isolation for MEMS resonant pressure sensor hermetic packaging using non-photosensitive benzo-cyclo-butene (BCB) from Dow Co. According to the bonding process, pre-bake time, pumping time, pressure placed on the sensor and the thickness of crosslink layer are the most important factors. Stress isolation is designed to minimize thermal stresses to the resonant pressure sensor package. Experimental results show that this bonding process is a viable for MEMS resonant pressure sensor with the bonding temperature below 250°C, measured bonding strength more than 30MPa, the temperature drift less than 0.05%/°C in the range of -40°C to 70°C(10% of that without stress isolation), and the bonding strength maintains well after thermal treatments, handling, bench testing and implantations.
Debundling of Single Walled Carbon Nanotubes by HPC in 1-Propanol and Water
Authors: Wang Yan , Liu Yang Qiao , Sun Jing , Gao Lian
Published: August 2011

A novel surfactant, hydroxypropyl cellulose (HPC), was firstly used to debundle Meijo single walled carbon nanotubes (SWNTs) in distilled water and 1-propanol. As comparison, common surfactants (SDBS and Triton) were used to disperse Meijo SWNTs in 1-propanol and distilled water. And the dispersibility of mixed surfactants, HPC/SDBS and HPC/Triton, were also tested. After short ultrasonication and centrifugation, stable supernatant of HPC-SWNTs has been obtained, and HPC show the best dispersibility to Meijo SWNTs. The HPC-SWNTs solution was used to prepare transparent conductive films on PET substrate by spray coating method. After being soaked in 1-propanol and HNO3, the sheet resistance decreased from 8,440 Ω/□ to 4,175Ω/□ at 90% transmittance. TEM, UV-Vis-NIR spectra, and Raman spectra were performed to characterize the SWNT solutions and films.
Development of Novel Filter Materials for the Treatment of First-Flush Rainwater
Authors: Kim Ree Ho , Kim Hana , Lee Jung Hun , Lee Sang Ho
Published: August 2011

First-flush rainwater is of great interest in the research on urban environmental protection and rainwater harvesting. It deteriorates the chemical, physical, and microbiological quality of the collected/stored water as well as the water body in an urban area. Accordingly, effective and economic treatment of first-flush rainwater is highly required. This study aimed to develop a technology for the treatment of first-flush rainwater using new filters made of wood fiber mat, dental cotton, and feldspar. The removal of pollutants in first-flush rainwater with each filter material was evaluated. Experiments were carried out using an artificial rainwater solution made of road dust particles (less than 200 um small) and D.I. water that contained ionic species. The SS concentration of the solution was set between 30 and 150 mg/L. Prior to the experiments, the fiber materials were pretreated with NaOH, FeCl3, and Al2O3. The batch test results indicated that the phosphate removal efficiency of the wood fiber mat was 8.6%; of the dental cotton, 34.7%; and of the feldspar, 1.7%. On the other hand, the heavy metal removal efficiency of the wood fiber mat was 91%; of the dental cotton, 26%; and of the feldspar, 0%. The highest cation exchange capacity of the wood fiber mat that was pretreated with NaOH was attributed to the existence of carboxyl and hydroxyl functional groups in the wooden polymers. Combinations of filter materials were found to have been effective in removing particles in the rainwater. The combination of the wood fiber mat with polyethylene beads resulted in 97-98% particle removal. Other combinations such as DP (dental cotton and polyethylene beads), MF (wood fiber mat and feldspar), and DF (dental cotton and feldspar) showed particle removal rates of 90-95%, 84-96%, and 87-94%, respectively. After 30 minutes, all the combinations had a particle removal rate of over 90%.
Effect of Particle Size Distribution on the Workability of Alumina-Based Castable Refractories
Authors: Ming Zhao Jing , Xun Yang Zheng , Hong Hwang Kyu , Hwan Park Sang
Published: August 2011

Slagging coal gasifiers operate at temperatures as high as 1650°C in a reducing environment so that combustion chambers are lined with high chromia refractories. The quality of these refractories applied on IGCC should be a key factor that affects the entire cost of electric power production. In this study, low cost chromia-alumina castables were chosen as candidate refractories for IGCC. To enhance the workability of chromia-alumina castables, ultrafine alumina powder was added to improve the workability. It’s proved that the specific surface area and particles size distribution of ultrafine powders in matrix part greatly affect the flow values and microstructures.
Mechanical Behaviors and Texture Development of the Extruded Magnesium AZ31 Alloys
Authors: Park Joon Sik , Kim Jeong Min , Song Young Ho , Lim Dong Wook , Yang Won Seok , Shin Hee Taek , Koo Yeon Soo
Published: August 2011

Mg alloys are one attractive material in applications of transportations and mobile electronics due to their high specific strength compared with other structural materials. However, Mg alloys often exhibit relatively low strength and/or low surface stability, which can limit the practical application of the alloy system. In this perspective, thermo-mechanical treatments of the alloy can give enhanced materials strength, so that the application of the alloy system can be extended towards new structural parts for requiring the light nature of the alloy system. In this study, a high temperature extrusion has been carried out for the commercial Mg alloys (AZ31). The extrusion temperature and extrusion ratio critically affected the alloy strength and ductility. The texture development and alloy strengths with respect to the extrusion conditions have been discussed in terms of microstructural observations and phase analyses.
Preliminary Studies on the Preparation of New-Style White Mud / KGM Membrane
Authors: Chen Yan , Lin Xiao Yan , Wang Wei Xing
Published: August 2011

The influences of preparing conditions on mechanical properties of the white mud (WM) / Konjac glucomannan (KGM) composite film (MKG) were investigated by orthogonal experiments. Zeta potential analysis and DSC were used to characterize the properties of WM and MKG. The results show that the mechanical properties of MKG films can be enhanced through proper modification. Optimized processing parameters of MKG film are described as following: the ratio of KGM, WM, benzoic acid, sodium dodecyl benzene sulfonate(LAS) and stearic acid was 100:14:2:0.24:0.14. 1.00 (wt) % of KGM powder was swelled in deionized water with WM modified by stearic acid, benzoic acid and LAS, stirred for 1.5 hour at 60°C and then paved on plate and dried at 40°C for 15 h to form the MKG film.
Synthesis and Characterization of Flower-Sphere MoS2
Authors: Zhou Jun , Lan Xin Zhe , Ren Ping , Zhang Qiu Li , Song Yong Hui , Chen Xiang Yang
Published: August 2011

The flower-sphere molybdenum disulfide has been synthesized by reaction of Na2MoO4 and CS(NH2)2 with NH2OH·HCl or H2C2O4 as reductant. The microstructure and chemical composition of the product were characterized by means of X-ray diffraction and scanning electron microscope. XRD patterns showed that the molar ratio of Mo to S had a great effect on the purity of the product. When the molar ratio of Mo to S was 1:5, the product was nearly pure MoS2. SEM images showed that the particle size increased as the molar ratio of Mo to S reduced. The MoS2 microspheres had rough surfaces and were constructed with sheet-like structures in the two systems. But the product from the system of NH2OH·HCl as reductant has the bigger particle size, clearer petal-sheets, coarser surface and weaker agglomeration than that from the system H2C2O4 as reductant. The possible chemical reactions in hydrothermal systems were preliminarily discussed.
Effect of Annealing on Ag-Doped Submicron Silica Powder Prepared with Modified Stöber Method
Authors: Larismaa Juha , Honkanen Toni , Ge Yan Ling , Söderberg Outi , Friman Michael , Hannula Simo Pekka
Published: August 2011

Antibacterial silver can be used against such micro-organisms as bacteria and molds. When Ag nanoparticles are attached to an inorganic carrier, e.g., silica long-term antimicrobial functionality can be gained. Such Ag-SiO2particles are potential for water purification or bactericidal applications. In this work, submicron sized silica particles doped with Ag were prepared by the modified Stöber method. The as-prepared powder was air-dried and annealed for 75 minutes at 573, 673, 773, 873, 973, 1073, 1173, or 1273 K in air. The powders were studied by DSC/TGA, XRD, SEM, TEM and UV-vis methods. The as-prepared powder consisted of round silica particles having size around several hundred nanometers. XRD and SEM studies confirmed that the powder consisted of metallic silver nanoparticles on the submicron silica surface after annealing at 873 K or higher. According to the SEM study the silver particles had an average particle size between 19-400 nm depending on the annealing temperature. DSC was used to determine the phase transformation temperatures. After annealing the Ag-SiO2powder at 873 K the TEM study suggested that the silver had crystalline structure. The XRD studies confirmed that silver appeared as a FCC crystal structure. The UV-vis measurements of Ag-SiO2powder annealed at and below 773 K showed a steady increase in absorption with decreasing wavelength without absorption peaks. Annealing at 873 K and above resulted in a strong peak in between 404 nm and 416 nm. This peak can be attributed to the surface plasmon resonance of silver nanoparticles.
Effect of Melt Treatment on Forming and Brazing Characteristics of 4343/3003/4343 Aluminum Clad Sheet
Authors: Shin Je Sik , Chang Sung Ho
Published: August 2011

In this study, it was aimed to investigate the effects of grain refining of 3003 core alloy on forming and brazing characteristics of 4343/3003/4343 aluminum clad sheet. Ti inoculation level was changed up to 0.1wt% by adding Al-10Ti master alloy into 3003 aluminum melt as grain refiner. The three-layer aluminum clad sheets of 0.7 mm thickness were fabricated by hot roll bonding process. The forming and brazing characteristics were evaluated by measuring FLD (forming limit diagram), bonding strength and sagging resistance.
Field Application of the Pelletized Fibrous Filter Device
Authors: Kang Sung Won , Yun Sang Leen , Kim Seog Ku , Kwak Pill Jae , Ahn Jae Hwan , Ban Hyo Jin
Published: August 2011

Due to its irregular structure, the efficiency of the pelletized fibrous filter can be improved if the target substance is line-shaped. Thus, this study was conducted to examine the applications of the pelletized fibrous filter for biological sewage water with line-shaped particles. Towards this end, the pelletized fibrous filter was applied to advanced treatments in which the particles in the sewage water in the supernatant using solid-liquid separation from the final-settling reservoir was filtered with pelletized fibrous filters. To determine the process efficiency of the filter device, a multiparameter water quality analyzer and a data transmission system were established, which showed the efficient process even at a large distance, as well as the good operational status of the filter device. The pilot plant operation results showed that the concentration of TSS in the influent at 20-75 mg/L was reduced to 0.4-10 mg/L in the processed water. The average processing efficiency was 94.9% between 71.4 and 97.9%, and particularly, that of the suspended solids was very high. The results also showed that 27.2% CODMn, 22.5% T-N, and 30.0% T-P were removed.