bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Research of Dry Milling Powder Metallurgy Nickel-Based Superalloy with Coated Carbide Tools
Authors: Qiao Yang , Fu Xiu Li , Yang Xue Feng
Published: April 2012

Powder metallurgy (PM) nickel-based superalloy is regarded as one of the most important aerospace industry materials, which has been widely used in advanced turbo-engines. This paper presents an experimental study of high speed milling of powder metallurgy nickel-based superalloy with PVD (TiAlN-TiN) coated carbide tools. Experimental measurements of milling temperature and milling force were performed. Then the surface roughness and tool wear were analyzed and discussed under dry machining conditions. The results might be helpful to guiding the selection and design of tool materials and control of tool wear in high speed milling PM nickel-based superalloy.
FEM Analysis during Extrusion of Round-To-Pentagonal Sections through Converging Dies
Authors: Rout Akshaya Kumar , Maity Kali Pada
Published: April 2012

The linearly converging die plays a significant role in the extrusion process of section products in terms of reduction in extrusion load and improvement of product quality. With the help of upper bound method based on dual stream function method. Very few investigations have been reported when product and billet geometry are dissimilar using linear converging die. Dual stream function method is incapable of predicting kinematically admissible velocity field in the above case, SERR technique (Spatial Elementary Rigid Region) is the only alternative. In the present investigation, a reformulated SERR technique has been used to determine non-dimensional extrusion pressure and optimum die profile both for frictionless and friction conditions. SERR technique based on discontinuous velocity field is applicable for this case. In the present investigation, non-dimensional extrusion pressure and optimum die length has been determined for extrusion of pentagonal from round billet and the results are compared with the FEA results by using DEFORM 3D.
The Design and Simulation of Main Tool Carrier System in a Condition of Large Vertical Lathe
Authors: Zhang Ji Jun , Liu Xian Li , He Geng Huang , Yu Zhong Guang
Published: April 2012

To solve excessivly large deformation and vibration problems in machining large tube section, ensure the machining accuracy and quality of the tube section, the main tool carrier system of a large vertical lathe is designed, by simulation means of finite element, static analysis, dynamic modal analysis and dynamic response analysis are respectively carried on the main tool carrier structures designed. A reasonable overhang length of the tool in the tool carrier system is given through static analysis, dynamic modal analysis show the higher natural frequency of the tool carrier system, the production of cutting resonance can be avoided, the maximum response and corresponding stress conditions of the system under the harmonic loads are given by dynamic response analysis, analysis results show that the sustainable dynamic characteristics of tool carrier system can meet the machining requirements.
Matching Relationship between Shaft Material and Fatigue Properties under Complex Loading Condition
Authors: Zhang Wo Bo
Published: April 2012

According to analyzing the influence factors of shaft fatigue properties, the matching relationships between fatigue properties and shaft material as well as other relevant factors have been investigated. And the matching relationships have been demonstrated via experimentation. A useful method is established to enhance material fatigue toughness. Considering the aspects of safety, economy and the requirement of fatigue strength, when the dimension of the structure could not be changed, the fatigue properties can be improved via increasing the fillet of the shaft. And 45 carbon steel is a highly recommended shaft material.
Research on the Principle of Compiled-Typed NC System
Authors: Zhou Liang , Ren Yan Hai , Lang Yue Dong , Liao Zhi Rong
Published: April 2012

To solve the conflict between OSs real time property and NC systems open and universal property [, a compiled-typed NC system is advanced based on analysis and research of the structure of modern NC systems. This kind of system can diminish the affection of the real-time OSs respond precision to machining with high speed and high precision and improve the frequency of interpolation sampling and respond precision. Motion control experiment and parametric curve direct interpolation experiment are finished by bonnet polishing machine tool with compiled-typed NC prototype system, proving that working principle of compiled-typed NC system is correct and validity.
FEM on Constitutive Equation of High Strength Stress Steel GCr15
Authors: Liu Xian Li , Yue Cai Xu , Yu Ming Ming , Zhang Jia Yi , Wu Ming Yang
Published: April 2012

Accuracy of cutting simulation model mostly depends on whether its material constitutive equation describes workpiece physical property under cutting state. It is necessary to research on the constitutive properties of cutting material in the high strain state of temperature. In this paper high strength steel GCr15 is used as a research object under the high speed cutting state. By FEM Johnson-cook constitutive model in Hopkinson Experiment is simulated, and the sensitivity of constant on constitutive model is also analyzed. Also influence of temperature on workpiece material stress and strain is revealed. The result provides reference for Johnson-cook model parameters of high strength steel GCr15, and it provides theory basis of material properties analysis in cutting state as well.
Multi-Scale Fe Modeling Inconel718 Machining Process and Crack Initiation of Brittle Particle
Authors: Xu Xiao Jin , Ding Li Qiang , Zhang Xue Ping
Published: April 2012

nconel718 is particle reinforced metal matrix composites widely applied in important fields. To evaluate the impact of particles on the machined subsurface in Inconel718 during high-speed machining operation, a multi-scale orthogonal cutting finite element (FE) model is established. A cohesive element technique is adopted to predict particle crack initiation process. The multi-scale FE model is validated with experimental data in terms of cutting forces and chip morphology. The simulation reveals that particle has a great influence on surface roughness and the feed force when particles are located in the sub-surface within the depths of 30μm, and the cutting process has less effect on the particle crack initiation when the particles in the depths of more than 40μm or deeper. The interaction effects generated from particle sizes in the same depth are investigated on the cutting process and particle crack initiation.
Stability Analysis of Fractional Delay Differential Equations by Chebyshev Polynomial
Authors: Zhang Xiang Mei , Guo Xian Zhou , Xu Anping
Published: April 2012

The paper is devoted to the numerical stability of fractional delay differential equations with non-smooth coefficients using the Chebyshev collocation method. In this paper, based on the Grunwald-Letnikov fractional derivatives, we discuss the approximation of fractional differentiation by the Chebyshev polynomial of the first kind. Then we solve the stability of the fractional delay differential equations. Finally, the stability of the delayed Mathieu equation of fractional order is examined for a set of case studies that contain the complexities of periodic coefficients, delays and discontinuities.
Toughening Mechanisms and Wear Behavior of a TiC Whisker Toughening Alumina Ceramic Cutting Tool Composite
Authors: Liu Bing Qiang , Huang Chuan Zhen , Sun Ai Ling
Published: April 2012

Toughening mechanisms and flank wear behavior of a TiC whisker toughening Al2O3-based ceramic cutting tool composite were investigated. The results showed that the wear behavior of the tool composite was greatly influenced by the whisker toughening mechanisms, of which the toughening effects on the composite can increase with increasing cutting temperature. As a result, the tool composite could still possess enough high fracture toughness and flexure strength at high cutting temperature, which resulted in an interesting phenomenon that the wear resistance of the tool composite at higher cutting speed was higher than that of itself at lower cutting speed.
Research of Tool Parameter Design and Improvement of PCD Drill Machining CFRP
Authors: Ji Wei , Liu Xian Li , Wang Yi Wen , Li Ke Qiang , Yan Fu Gang
Published: April 2012

This paper presents a design idea of PCD tool drilling CFRP and analysis of experiment of two types PCD tools machining CFRP. Firstly, parameters of PCD drill including cutting edge type, clearance angle and two point angles were improved by the mean of surveying variation of axial load values and quality of CFRP hole exit. Secondly, two types of burrs were defined from aspects of burr generated mechanism by observing plenty of burr pictures. Lastly, making use ofMATLABsoftware, function between axial load and hole numbers were ensured by data fitting in tool life analysis.
Nano-Indentation Simulation Study Based on Parallel Computing
Authors: Zhu Ying , Song Sen , Xie Ling Ling , Qi Shun He , Liu Qian Qian
Published: April 2012

This method of parallel computing into nanoindentation molecular dynamics simulation (MDS), the author uses a nine-node parallel computer and takes the single crystal aluminum as the experimental example, to implement the large-scale process simulation of nanoindentation. Compared the simulation results with experimental results is to verify the reliability of the simulation. The method improves the computational efficiency and shortens the simulation time and the expansion of scale simulation can significantly reduce the impact of boundary conditions, effectively improve the accuracy of the molecular dynamics simulation of nanoindentation.
Sub-Pixel Based Alignment of SMT Electronic Components
Authors: Li Xi Bing , Fan Yan Bin , Wang Jian Jia , Hu Qing Ming , Zhang Hong Xia , Bao Li
Published: April 2012

Rapid growth in modern technology places greater requirements on electronic products' performance and quality. For a PCB (printed circuit board) assembly of SMT (surface mounting technology) electronic components, restricted by its limited vision in image collection, a high-pixel CCD (charge coupled device) can only screen local images, and they need to be mosaiced, through matching and alignment, into a complete image, which is to be matched and aligned with a standard image then for image analysis. Therefore, image matching and alignment are of crucial importance to both the precision of image mosaic and the quality of SMT components. This paper proposed a sub-pixel based method, by which local images are marked, matched and aligned into a mosaiced image, which is matched and aligned with a standard image. The error analyses of matching and alignment for four common markers, i.e. circle, ellipse, square and rectangle, show that a square or rectangle marker is preferred for SMT electronic components; when the marker's center point serves as alignment point and the marked data are processed by sub-pixel algorithm, the alignment error can be reduced to about 0.2 pixel point, besides the sub-pixel based method can greatly improve precision when noise is fixed.
Time-Domain Simulation on Plunge Milling Ti-6Al-4V
Authors: Qin Xu Da , Gui Lin Jing , Jia Hao , Lu Cui , Li Hao
Published: April 2012

The research of cutting force and vibration has been gaining significant attention to improve machining efficiency and tool life in processing metals. In this paper, the plunge milling system is reduced to 3-DOF vibration system, and dynamical theoretical model and instantaneous undeformed chip thickness models are established based on dividing cutter tooth into finite number of small differential elements in the radial direction and discrete time domain. Based on regenerative chatter theory, the cutting force and vibration can be simulated by numerical algorithm. Compared the simulation results with experiments data, the milling force and vibration have a good agreement, which testify the correction of those models
Synthesis and Characterization of Electrical Properties of Bismuth Titanate
Authors: Yuen M.L. , Tan Y.P. , Tan K.B. , Taufiq-Yap Y.H.
Published: April 2012

Bismuth titanate solid solutions, Bi12+xTiO10+δ (0 ≤ x ≤ 0.6), were synthesized by conventional solid state method at sintering temperature of 700°C for 48 h. Structural studies were performed by powder X-ray diffraction (XRD) analysis and revealed that single-phase materials were obtained with a general formula of Bi12+xTiO10+δ (0 ≤ x ≤ 0.6). The electrical properties of all the single-phase samples were studied using the impedance spectroscopy technique. Further characterization of the materials was carried out using differential thermal analysis (DTA) and indicated that no phase transition was observed. The TGA analysis was observed and found that all the materials were thermally stable.
Structural Study of Lithium Strontium Borophosphate Crystal Using X-Ray Diffraction and Infrared Spectroscopy
Authors: Wong Poh Sum , Hua Wan Ming , Eeu Tien Yew , Hussin Rosli , Ibrahim Zuhairi
Published: April 2012

In order to study the influence of deionized water and heat treatment on the structure of the crystal, a compositional series of 20Li2O:20SrO:30B2O3:30P2O5 with deionized water and without de-ionized water as a solvent were prepared at 800ᵒC for different sintering time from 7 to 24 h. The crystalline phase and structural of 20Li2O:20SrO:30B2O3:A 30P2O5 crystal was studied using X-ray powder diffraction (XRD) and Infrared (IR) Spectroscopy. From the XRD result, samples prepared with deionized water as solvent displayed better crystalline respond. The samples showed a better crystalline structure when it was sintered for 24 h as compared to 7 h. The infrared spectra of the samples showed three distinctive regions around 1200 – 650 cm-1, 650 – 360 cm-1 and 360 cm-1 showing clear signs of boron units as the major host structure.
Effect of Compression Pressure on the Physical and Electrochemical Properties of Activated Carbon Monoliths Electrodes for Supercapacitor Application
Authors: Awitdrus Awitdrus , Deraman Mohamad , Talib Ibrahim Abu , Farma Rakhmawati , Omar Ramli , Ishak M.M. , Basri N.H. , Dolah B.N.M.
Published: April 2012

Green Monoliths (GMs) of self-adhesive carbon grain from fibers of oil palm empty fruit bunches were prepared by compression pressure at 1.43 × 107, 1.91 × 107 and 2.39 × 107 kg/m2, respectively. Activated carbon monoliths ACM-A, ACM-B and ACM-C prepared by CO2 activation from these GMs, respectively, were used as electrodes in supercapacitor cells which employed stainless steel 316L current collector and H2SO4 electrolyte. Evaluation of the electrochemical properties showed that ACM-A, ACM-B and ACM-C cells had specific capacitance of 30, 9 and 5 F/g, total ESR of 3.21, 4.95 and 7.33 Ω, specific power (maximum) of 173.41, 107.58 and 33.82 W/kg, and specific energy (maximum) of 0.67, 0.15 and 0.09 Wh/kg. These properties are directly associated with the surface area of the ACMs, i.e. 419, 336 and 302 m2/g for the ACM-A, ACM-B and ACM-C, respectively, indicating a direct effect of compression pressure on the physical and electrochemical properties of ACMs electrodes.
Microstructure and Phases of As-Cast and Heat-Treated Al-Si-Mg/AlN Composites Prepared by Stir Casting
Authors: Daud Abdul Razak , Wahab Mahamad Noor
Published: April 2012

Al-Si-Mg/AlN composites were prepared by stir casting technique. The amount of AlN added to Al-Si-Mg alloy was from 2 to 10 wt%. As-cast composites were solutionised at 540 °C for 4 h, quenched in warm water, 60 °C then artificially aged at 180 °C for 4 h. The microstructure of Al-Si-Mg matrix alloy contained dendritic α-Al, needle-like Si and very little inter-metallic compounds. As-cast Al-Si-Mg/AlN composites have rounded α-Al phase and needle-like Si where AlN particles dispersed surrounding α-Al. Needle-like Si transformed to spheroid after artificial aging. The size of α-Al phases of heat-treated composites containing 2 and 5 wt% AlN was bigger than that of as-cast composites whereas the heat-treated Al-Si-Mg/10% AlN composite has thin and elongated dendritic α-Al phases, and larger AlN particles.
Interdependencies of Critical Radius, Critical Energy and Surface Energy (CRESE) in Silicon Self-Assembled Nanodots
Authors: Sakrani Samsudi , Mat Isa Ahmad Radzi , Othaman Zulkafli , Ismail Abd. Khamim , Wahab Yussof , Idrees Fatima Aldaw
Published: April 2012

The interdependence parameters in the growth of silicon self-assembled nanodots are investigated. Accordingly, the critical radius, critical energy change and surface energy can be interpreted in terms of cubic function, where it produced a critical surface energy NS* and the corresponding r* and G*, called a CRESE point at a fixed growth temperature T when solved mathematically. It is defined as a limiting point at which equilibrium of the critical parameters take place at a constant temperature. Experiments were performed on the samples of amorphous silicon nanodots fabricated onto different non-crystalline substrates. A further analysis on the NS*-T plots revealed inverse linear relationships which converged at a CID point (o*,T*) when projected near the solidification temperature of silicon. The results suggested strong influence of atomic bonding at the nucleus-surface interface combined with higher surface roughness. In conclusion, there exists an equilibrium condition among the growth parameters which stabilizes the growth of amorphous silicon nanodots, as well as the existence of CRESE’s ideal destination (CID).
Cuprous Oxide Thin Films for a Photoelectrochemical Cell of ITO/Cu2O/PVC-LiClO4/Graphite
Authors: Halin Dewi Suriyani Che , Talib Ibrahim Abu , Daud Abdul Razak , Abd Hamid Muhammad Azmi
Published: April 2012

Cuprous oxide (Cu2O) thin films were formed onto indium tin oxide (ITO) coated glass substrate by sol-gel spin coating technique using different additives namely polyethylene glycol and ethylene glycol. It was found that the organic additives added had an important influenced on the formation mechanism of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible spectroscopy (UV-Vis). Based on the FESEM micrographs the grain size of film prepared by polyethylene glycol has smaller grain of about 83 nm with irregular shape. The highest optical absorbance film was obtained by the addition of polyethylene glycol which improved optical properties due to fine crystalline grain and thus decreases the scattering. The prepared cuprous oxide thin films were used as working electrodes for photovoltaic cell of ITO/Cu2O/PVC-LiClO4/graphite and tested using current-voltage characteristic under light illumination and also in the dark.
PEDOT:PSS Thin Film as Transparent Electrode in ITO-Free Organic Solar Cell
Authors: Rahman Zurianti A. , Sulaiman Khaulah , Shuhaimi Ahmad , Rusop Mohamad
Published: April 2012

Two types of polar solvent materials; namely glycerol and ethylene glycol (EG) were used in this study as dopants for PEDOT:PSS. The 2 to 10% of doped PEDOT:PSS were synthesized using sol-gel technique and were spin-coated onto glass substrate. The optical, conductivity and morphological characteristics of the doped PEDOT:PSS thin films were measured via UV-VIS spectrometer, two-point probes technique and AFM measurement, respectively. All films show direct band gap behavior and compared to the pristine thin film, the doped PEDOT:PSS show higher transparency in visible range. Furthermore, the conductivity of glycerol and EG doped PEDOT:PSS thin films were also improved due to the changes in molecule alignment and interchain interaction in the thin films.
Structural and Electrical Properties of Pb1-xYbxSeyTe1-y Quaternary Compound Synthesized by Solid State Microwave Assisted Plasma
Authors: Hmood Arshad , Kadhim Arej , Haslan Abu Hassan
Published: April 2012

Solid-state microwave as a method was used to synthesize quaternary compounds Pb1-xYbxSe0.2Te0.8 from initial components to obtain polycrystalline ingots with large grain size. Thin films of Pb1-xYbxSe0.2Te0.8 were then deposited onto glass substrates using thermal evaporation in vacuum, which have a polycrystalline rock salt (NaCl) structure for powders, and thin films. The field emission scanning electron microscopy (FESEM) images reveal that the Pb1-xYbxSe0.2Te0.8 thin films with Yb-doped have uniform crystal grain size and dense nanostructure. The thermoelectric properties of thin films were measured in the temperature range 298–523 K. The Seebeck coefficient of films increased with x when x=0.015, 0.03 and 0.045, while decreased for x=0.06−0.105.
Raman and Photoluminescence Spectroscopy of Nanocrystalline Diamond Films Grown by Hot Filament CVD
Authors: Rahman S.A. , Othman M.Z. , May P.W.
Published: April 2012

Nanocrystalline diamond films were grown by hot filament chemical vapour deposition (HFCVD) in a mixture of methane and hydrogen gases. Three straight parallel wires filament configuration were used in the HFCVD system for the deposition of the films studied in this work. The deposition pressure for the growth of diamond films in this hot filament chemical vapour deposition (HFCVD) reactor have been optimized to be at 20 torr with the methane and hydrogen flow-rates fixed at 2 and 200 sccm respectively. The films studied in this work were grown at low deposition pressures of 2 and 5 torr using the same gas flow-rates used for the optimized diamond film growth including an additional film grown at pressure of 5 mbar with the methane flow-rate reduced to 1 sccm. The morphology showed the formation of closed packed diamond grains for the film grown at 5 torr with methane and hydrogen flow-rates fixed at 2 and 200 sccm. Decrease in pressure and methane flow-rate produced significant changes to the morphology of the diamond grains formed. X-ray diffraction showed that diamond phase phases were dominant in the films deposited at higher pressure. Raman and photoluminescence (PL) spectral analysis were performed using spectra acquired at 325 and 514 nm excitation energies. Raman analysis revealed that increase in deposition pressure from 2 to 5 Torr resulted in the transformation of the film structure from diamond-like-carbon to nanocrystalline diamond structure. UV excitation produced high PL emission intensity at 2.1 eV and the PL intensity was highest for the films deposited at the lowest pressure. Visible excitation on the other hand produced low intensity broad PL emission for all the films between 1.2 and 2.5 eV and the PL intensity was high for the films deposited at the highest deposition pressure.
Effect of Ca Substitution at Y-Site of YB2C3O7 Superconductor Prepared via Co-Precipitation Method
Authors: Hidayah H.N. , Yahya S.Y.S. , Azhan H. , Azman K. , Hawa J.S. , Norazidah A.W.
Published: April 2012

The effect of Ca substitution in Y1-xCaxBa2Cu3O7 superconductor prepared via co-precipitation method has been investigated. The concentration of Ca substitution was varied from x = 0.05 to x = 0.20. The samples were characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (SEM), resistivity measurement and current density measurement (without magnetic field). The critical temperature of the samples decreased as the concentration of Ca be increased whereby the highest value of critical temperature (Tc zero) was 83 K at x = 0.05. The crystallographic structure of pure sample was evidenced to be orthorhombic form where a ≠ b ≠ c.. At x = 0.10, the microstructure showed an improvement in grain alignment compared to other Ca concentration. The critical current density (Jc) increased with Ca concentration. The value of Jc for x = 0.05 at 50 K and 60 K was 1.51 A/cm2 and 1.00 A/cm2, respectively.
Strain Modification of Band Edge Energies in a Pyramidal InAs-GaAs Quantum Dot System
Authors: Ripan Gregory Henry , Gopir Geri , Othman Ahmad Puaad
Published: April 2012

We present the calculated band edge energies altered by strain in a nanostructure system of a pyramidal InAs quantum dot buried in a GaAs substrate. Our zinc-blende supercell system of dimension 11.9 nm × 11.9 nm × 8.5 nm and 55119 atoms contains a pyramidal In770As886 quantum dot of 1656 atoms with height of 3.03 nm and square base of length 6.06 nm. The strain energy of this nanostructure system is minimized by employing the Keating formulation of interatomic potential and Monte Carlo relaxation method via the Metropolis algorithm. This relaxation is run for 20 million Monte Carlo steps at simulation temperature of 4.2 K. The calculated strain is then used to determine the conduction and valence band edge energies of the nanostructure. We find that along the [001] growth direction in the InAs quantum dot region, strain increases the conduction band edge energy by 0.6 eV and in the valence band strain results in relatively sharp wells at the dot base for heavy holes and at the dot tip for light holes. Thus, our calculation predicts that strain leads to increased band gap and spatial splitting of holes in this nanostructure system.
Effect of Paper Sludge Ash on the Compressive Strength of Plaster of Paris/Paper Sludge Ash Composites
Authors: Lim Kar Keng , Shamsudin Roslinda , Hamid Muhammad Azmi Abdul
Published: April 2012

In this study, paper sludge ash, a waste from pulp and paper industry was used as a filler in fabricating Plaster of Paris/paper sludge ash composites. Various percentage of paper sludge ash was used, namely 1wt.%, 3wt.%, 5wt.% and 7wt.%. The effect of paper sludge ash on the compressive strength of the Plaster of Paris was studied. The mixed powder of paper sludge ash and Plaster of Paris were form into a 6 mm diameter and 12 mm height cylindrical samples. The composites were characterized theirs density where it shows that the density decreased as the amount of paper sludge ash increased. The compressive strength of the composites also decreased from 11.67 MPa without paper sludge ash addition to 0.50 MPa at 7wt.% paper sludge ash. However, the requirement of strength for Plaster of Paris in industry is between 8.96 MPa to 20.68 MPa. From the SEM observation, sample contain higher percentage of paper sludge ash exhibited more porosity. Therefore with the addition of 1wt.% of paper sludge ash into Plaster of Paris can be a promising construction material.
Effect of Propylene Carbonate on Ionic Conductivity of MG49-TiO2-LiClO4 Composites Polymer Electrolytes
Authors: Ahmad Azizan , Low Shwu Ping , Almakhzoom Fadwa Saad Addaokali , Rahman Mohd Yusri Abdul
Published: April 2012

The effect of plasticizer (PC) on the conductivity and chemical interaction of polymer electrolyte of MG49–PC–LiClO4–TiO2 has been investigated. The electrolyte films were successfully prepared by solution casting technique. Alternating current electrochemical impedance spectroscopy was employed to investigate the ionic conductivity of the electrolyte films at 25 °C, and the analysis showed that the addition of propylene carbonate (PC) plasticizer has increased the ionic conductivity of the electrolyte up to its optimum level. The highest conductivity of 2.54×10−4 Scm−1 was obtained at 30 wt.% of PC. Fourier transform infrared spectroscopy measurement was employed to study the interactions between lithium ions and oxygen atoms that occurred at carbonyl (C=O) and ether (C-O-C) groups. XRD pattern showed that the crystallinity phase was reduced at the highest conductivity.
Effect of Annealing Temperatures on Formation of Na0.5Bi0.5TiO3 and (Na0.5Bi0.5)0.96Ba0.04TiO3 Ceramics Prepared via Sol Gel Method
Authors: Haji Jumali Mohammad Hafizuddin , Mohamad Siti Mariam , Awang Rozidawati , Yahaya Muhammad , Said Mohd Riduan M. , Salleh Muhammad Mat
Published: April 2012

The effect of annealing temperatures on the formation of pure perovskite Na0.5Bi0.5TiO3 (NBT) based ceramics prepared by sol gel method has been investigated. The NBT sol was prepared using NaCH3COO, C6H9BiO6 and Ti(C4H9)4 with 2-methoxyethanol and glacial acetic acid were used as solvents. The BaTiO3 sol was synthesized using C4H6BaO4 and Ti(C4H9)4 with acetic acid and ethanolamine were used as solvents. The (Na0.5Bi0.5)0.96Ba0.04TiO3 (NBBT) sol was prepared by mixing appropriate amount of NBT and BaTiO3 sols. Then NBT and NBBT sols were dried at 200oC for 24 h, ground and subsequently annealed at temperatures ranging from 440oC – 640oC for 5 min. Formation of NBT and NBBT ceramics was examined using XRD technique. X-ray diffractograms reveal that the NBT ceramic with rhombohedral structure starts to form at 540oC and complete crystallization is achieved at 620oC. Addition of 4vol% of BaTiO3 sols drastically reduces the crystallization temperature of NBBT ceramic to 460oC and a pure single phase ceramic is achieved at 520oC. Despite retaining the same rhombohedral structure, the NBBT exhibits lattice parameters expansion indicating a successful Ba substitution which is also confirms by the absence of BaTiO3 peaks in the diffractograms. Both ceramics exhibit great thermal stability with additional increment in annealing temperatures.
Phase Analysis in the Crystallization of Cordierite
Authors: Norfadhilah Ibrahim , Ahmad Zainal Arifin , Hasmaliza Mohamad
Published: April 2012

In this study, α-Cordierite was synthesized via glass-route using kaolin, talc and dolomite as starting raw materials. All the materials were mixed using non-stoichiometric xCaO.21-xMgO-26Al2O3-53SiO2 and melted at 1540°C for 4 h followed by quenching. Various weight percentage (wt%) of CaO (0, 1, 3, 5, 6, 7, 8, 10, 15 wt %) from dolomite was used to study their effects on the formation of α-cordierite. Quantitative phase analysis of sintered samples was carried out using Rietveld method and the results demonstrated total weight percentage of α-cordierite as a function of various composition of CaO. The Rietveld results were normalized to 100 wt% of crystalline fraction, so the hypothetical amorphous content of samples was assumed to be negligible. Quantitative analysis showed that amount of α-cordierite decreased with increasing CaO. Forsterite phase increased with increasing amount of CaO and anorthite phase start to crystallize at 5 wt% CaO. The precipitation of anorthite may be attributing to the glass composition locating in the field of anorthite phase.
Optical Absorption of Er3+/Nd3+ Co-Doped Tellurite Glass
Authors: Akmar Roslan S. , Rahim Sahar M. , Arifin Ramli , Ghoshal Sib Krishna , Rohani M. Supar , Hamzah Khaidzir
Published: April 2012

Tellurite glasses of varying Er3+/Nd3+ concentration were successfully prepared by melt-quenching method. The X-Ray diffraction pattern was determined by using Siemens Diffractometer D5000 while the optical properties were measured using Shimadzu 3101 pc UV-VIS NIR scanning spectrophotometer. It was found that the diffraction patterns of all samples showed glasses characteristics. The optical band gap, Eopt¬ increased proportionally with the content of Er¬2O3 but Urbach energy, ∆E decreased due to the increasing Er2O3 contents.
Study on the Optical and Electrical Properties of Organic Semiconductor Thin Films for OLEDs
Authors: Gu J.H. , Zhong Z.Y. , He X. , Yang C.Y. , Hou J.
Published: April 2012

Organic semiconductor thin films of aluminum (III) bis(2-methyl-8-quninolinato)-4- phenylphenolate (BAlq), -naphthylphenylbiphenyl amine (NPB), and tris(8-hydroxy-quinoline) aluminum (AlQ) for organic light-emitting diodes (OLEDs) were deposited by the vacuum sublimation technique. The optical properties in the UV-visible region of the thin films were investigated by optical transmittance and absorption spectra. The band gaps were obtained from direct allowed transitions at room temperature by means of the Tauc plots. The Urbach energy and the slope of Urbach edge were evaluated, respectively according to the Urbach-edges method. The thin film devices of sandwich structure were fabricated using these organic semiconductor materials, in addition, the effective carrier mobility, free carrier density, and electrical conductivity of the thin films were calculated in terms of the measured current-voltage characteristics of the devices.
Luminescence Properties of Ce3+ and Tb3+ Doped Strontium Pyroborate Phosphors
Authors: Sun Jia Yue , Lai Jin Li , Sun Yi Ning , Xia Zhi Guo , Du Hai Yan
Published: April 2012

Ce3+ and Tb3+ co-doped Strontium Pyroborate phosphors were synthesized by the solid-state method. The luminescent properties of phosphors were investigated by using the photoluminescence emission and excitation spectra. Under the excitation of near ultraviolet (n-UV) light, Ce3+ and Tb3+ co-doped Strontium Pyroborate phosphors exhibited blue emission corresponding to the f-d transition of Ce3+ ions and green emission bands corresponding to the f-f transition of Tb3+ ions, respectively. In the Ce3+ and Tb3+ co-activated samples the Ce3+ ions strongly sensitize the luminescence of the Tb ions. The Ce3+ and Tb3+ co-doped Strontium Pyroborate phosphor could be considered as one of double emission phosphor for n-UV excited white light emitting diodes.
First Principles Study of the Electronic Structure of In1-xGaxN
Authors: Mi Ling Ling , Zhao Guo Zhong
Published: April 2012

The In1-xGaxN electronic structure is calculated by First principle based on density functional theory. The energy band structures and density of state is calculated. It can be found that the hybridization of the Ga4s4p and N2p，In5s5p is stronger than that of N2p，In5s5p in the undoped system. And it leads to the valence band moving towards to low energy level and the conduction band moving to the high energy level. Correspondingly, we can find a larger band gap than that of undoped InN. In conclusion, the wide band gap lead to the blue shift and Moss-Burstein effect occurs near the top valence band.
Influence of Structure Unit and the Distribution on the Low-Velocity Impact Property of the 3D Woven Composites
Authors: Li Yan Qing , Sun Jia Ying , Tian Wei , Zhu Cheng Yan
Published: April 2012

In this paper, the low-velocity impact properties of the 3D woven composites were tested. Through the study on the relationship of absorbed energy and material structure, the impact resistance of the composites has been discussed. The research results show that the low-velocity impact resistance of quasi-orthogonal composites is the best, the low-velocity impact resistance of orthogonal composites is the worst and angle tangled of interlayer joint composites stand somewhere between the two. Adding quasi-orthogonal unit into the structure, the low-velocity impact property of the composites can be enhanced efficiently. On the other hand, if the unit distribution of the enforced fabric is changed, the break time and break point will be changed. But the effect on the total absorbed energy is not obvious.
Interfacial Fracture Strength of Viscoelastic Inclusions in a Polymer Blend
Authors: Zhang Ming Hua , Lei Jin Tao , Chen Jian Kang
Published: April 2012

The interfacial fracture strength in polymer blends is investigated in this study. The constitutive relations of polymeric matrix and inclusions are both approximately described by linear viscoelastic models. It is assumed that the interfacial de-boding between inclusions and matrix is dominantly induced by the hydrostatic component of remote stress. Based on the assumption, the interfacial de-bonding of a viscoelastic inclusion embedded in an infinite polymeric matrix is analyzed. It is found that the size of inclusion will strongly affect the magnitude of critical stress, and the effect of Poisson’s ratio on the de-bonding is so small that can be ignored.
Effects of Feed Water Conditions on Performance of Electrodeionization Process for Removal of Ni2+ from Dilute Solution
Authors: Lu Hui Xia , Bu Shao Feng , Wang Jian You
Published: April 2012

Electrodeionization (EDI) is being applied more and more to treat wastewater containing heavy metal ions, especially for electroplating rinsing wastewater. The effects of feed water conditions including concentration, pH and temperature on the performance of EDI process for removal of Ni2+ from dilute synthetic wastewater were investigated systematically in this paper. It was found that the dilute resistivity of the EDI module descended from 1.5-2.8MΩ•cm to 0.36-0.45MΩ•cm while the influent Ni2+ concentration increased from 45 mg•L-1to 63mg•L-1. Existence of some H+ in feed water would push the stack current up. An increase in temperature of feed water would facilitate the ion exchange and diffusion and thus promote mass transfer. It was indicated that feed water conditions had a significant effect on separation performance of EDI process for treating dilute solutions containing heavy metal ions. Pure water production could be accomplished and water reuse could be realized via EDI technology by appropriately restricting feed water conditions.
Study on the Shading Property of the Fabric
Authors: Tian Wei , Luo Qian Qian , Jiao Guo Yan , Zhu Cheng Yan
Published: April 2012

In order to study the shading property of the fabric, there are several parameters of the fabrics were tested, they are include the transmission and reflectivity for the Ultraviolet light, the transmission and reflectivity for the visible light. From the test results, following conclusions can be gotten: under same situation, the percent of void for the fabric will affect the transmission of the Ultraviolet light and the visible light. When the interweaving frequency is bigger and the float is shorter, the reflectivity of the Ultraviolet light is lower and the reflectivity of the visible is higher.
Mechanical Property and Conductivity of Polyaniline-Poly(Vinyl Alcohol)Composite Films
Authors: Wang Xiao Hua
Published: April 2012

The polyaniline(PANI)-poly(vinyl alcoho1)(PVA) composite films with the doping of hydrochloride (HCl), dodecylbenzenesulfonic acid (DBSA) or aminosulfonic acid (NH2SO3H ) were prepared by in-situ polymerization. Effects of PVA content, HC1 content, oxidant ammonium persulfate(APS)dosage, reaction time and film drying temperature on tensile strength of the HCl-PANI-PVA composite film were studied. The conductivity of PANI-PVA composite film with the doping of HCl is the highest of 13.2S.cm-1 among them. The tensile strength of the film is improved greatly due to effective mixture of PANI and PVA. The tensile strength of the composite film substantially depended upon the mass fraction of PVA. The tensile strength of the HC1-PANI-PVA composite film reaches the maximum of 60.8 MPa, in case the PVA content is 40%, the C(HC1)=1.0 mol/L，reaction time is 4.0 h, the n(APS/An)=1.0, and film drying temperature is 80°C.
Improvement on Dyeing Performance of Different Bifunctional Reactive Dyes for Soybean Protein Fibers
Authors: Lv Jing Chun , Lin Hong Qin , Zhou Qing Qing , Li Jing
Published: April 2012

This study assesses dyeing performance of reactive dyes with monofluorotriazine and modified cvinyl-sulfone bifunctional reactive groups in alkaline/acid denaturalization bath to the soybean fibers. It has been shown that 3~4 of the dyeing pH value, 60 minutes and 70°C of dyeing time and temperature were selected for denatured bath. The denaturalization bath can dramatically improve exhaustion and fixation and significantly decrease the chromaticity of the dyeing effluent. Besides, colorimetric properties, fastness and mechanical strength of the dyed fabrics were evaluated to indicate applicability of this dyeing process of soybean protein fibers.
The Red-Emitting Phosphor of Sm3+-Doped Y2Si4N6C
Authors: Sun Jia Yue , Zeng Jun Hui , Zhu Ji Cheng , Sun Yi Ning , Du Hai Yan
Published: April 2012

A new red-emitting Rare-earth silicon carbonitrides phosphor, Y2Si4N6C, was prepared by a carbothermal reduction and nitridation method. X-ray powder diffraction (XRD), the photoluminescence excitation and emission spectra, temperature dependent was measured. The emission spectrum obtained by excitation into 410 nm contains exclusively the characteristic emission of Sm3+ at 568, 607 and 654 nm which correspond to the transitions from4G5/2to6H5/2,6H7/2, and6H9/2of Sm3+, respectively. The strongest one is located at 606 nm due to4G5/2to6H7/2transition of Sm3+.
Mixture Calculation of Chromium Ore Smelting Reduction Process in a Converter
Authors: Liu Yan , Jiang Mao Fa , Wang De Yong
Published: April 2012

The mixture calculation of producing stainless steel crude melts by chromium ore smelting reduction in a 150 t converter is carried out by use of the empirical data and the calculation method of refining plain carbon steel in a converter, according to the blowing conditions of 185 t smelting reduction converter of No.4 steelmaking shop in Chiba Works of JFE Steel. The calculation results show that the required total consumption of chrome ore, coke and limestone in the smelting reduction process is 224.942 kg, 154.9 kg and 99.223 kg, respectively, under the conditions of this calculation. The total amount of slag includes the amounts of hot metal elements oxidation into slag, lining erosion into slag and chromium ore, coke and adding flux into the slag, which is calculated respectively according to the basic raw data and the set values of process parameters. The slag component is confirmed, namely, the actual basicity w(CaO)/w(SiO2)=2.6, the percentage of CaF2 in slag is 3~4 wt%, and the calculated w(MgO)/w(Al2O3)=0.7. In the actual production, the addition of chrome ore, coke and flux is increased by 3%, 2% and 1%, respectively.
The Influence Faction to the Crude Oil Emulsion Stability
Authors: Zhang Hong Jing
Published: April 2012

At present, the exploited crude oil is about 80% in the presence of crude oil emulsion in the world. More and more research to study stability of the crude oil is developed. Firstly, the basal knowledge of the crude oil emulsion and interfacial film are introduced in this paper. The main reason that crude oil can come into being stable emulsion is it has natural emulsifiers, which can form interfacial film, then the author emphasizes on four natural emulsifiers of the crude oil’s components: asphaltenes, gelatine, paraffine and solid particles, which play very important role in the crude oil emulsion’s stability. The natural emulsifiers, such as asphaltenes, gelatine, can be absorbed between water and oil to form interfacial film that has some visco-elasticity. The stronger is interfacial film, the more stable is the crude oil emulsion.
Effect of Surface Roughness on Nanocontact: Quasicontinuum Simulation
Authors: Jiang Wu Gui , Wang Zheng Wei
Published: April 2012

By using the two-dimensional quasicontinuum method, the nanocontact between Ni indenter and single crystal Cu substrate with a smooth or rough surface is simulated. The contact force varies in a nonlinear fashion with the increasing indenter displacement, including several force drops. The atomic-scale deformation mechanism in the Cu substrate during nanocontact process is monitored. Shockley partials, Lomer-Cottrel locks as well as twinning faults are observed at the force drops. The Lomer-Cottrel locks play an important role in smooth surface nanocontact process, and they insure that Cu substrate undergoes elastic deformation dominantly during nanocontact process. The contact forces calculated from the Maugis-Dugale (M-D) theory show a good agreement with those obtained by the QC simulation in the smooth surface nanocontact process. It must be noted that the M-D theory is no longer suitable to describe the rough surface nanocontact problem due to the severe plastic deformation in the asperities of the substrate when the characteristic size of roughness is on the order of the indenter depth.
Numerical Simulation of Water-Lubricated Rubber/Chromium Coating Pair Test
Authors: Wang You Qiang
Published: April 2012

The elastohydrodynamic lubrication (EHL) geometric model of the water lubricated rubber bearings under standard experimental conditions with water lubrication was established. The complete numerical solution of the EHL model was obtained by using multi-grid technique. The results show that the EHL state can be only established under high relative velocity and mild load conditions between the rubber block and the chromium coating on steel with sufficient water. The numerical results are good agreement with the experimental data.
Optimum of Drawbead Design and Restraining Forces by Sensitivity Analysis Method Combined with Inverse Approach in Sheet Metal Forming Process
Authors: Yi Guo Feng , Liu Yu Qi , Du Ting
Published: April 2012

A improved algorithm to optimize the restraining force of equivalent drawbead was proposed base on BGFS(Broyden-Fletcher-Goldfarb-Shanno) algorithm combined with a simplified finite element method called inverse approach(IA). The forming limit curve (FLC) and the wrinkle limit curve (WLC) were considered as the objective function to reflect the influence of Fracture and wrinkle defect in sheet metal forming process. The optimized result was more accurate than those procedures only consider the variation of thickness distribution. The optimized process was also very efficient due to the simplified assumptions of the IA. Two stamping parts were presented to validate the accuracy of this optimum algorithm.
A Study on the Application of Design Thinking Strategy to Form Generation System
Authors: Tseng Sei Wo Winger , Lin Chi Hong
Published: April 2012

There are two kinds of thinking strategy, which are vertical thinking and lateral thinking [1]. Nowadays, there are few computer-aided designs using design thinking strategy. Most computer aided designs combine the consumer's emotional and pattern matching. Base on this reason, this study's purpose is the application of design thinking strategy to computer-aided design, and use the Model of Two Paths which proposed by Tseng & Chang [2], and combined parametric modeling of derivatives design. The authors hope in the future, the computer systems can assist the designer in thinking. Currently, the study found the process of parametric modeling form generation that changes the spatial relation which is similar to Jumping thinking of lateral thinking. The shape evolution between different vocabulary is similar to Triggering thinking of lateral thinking [2].
Differential Evolution Algorithm with Hybrid Discrete Variables and its Application to Mechanical Optimization
Authors: Che Xiao Yi , Liu Qi Yuan , Luo You Xin
Published: April 2012

The optimization design about hybrid discrete variables is very significant but also difficult in engineering, mathematics for programming and operational research. Aimed at shortages of existing optimum methods, in this paper, according to the search mechanism of differential evolution algorithm (DEA), a new differential evolution algorithm is proposed to complex optimization problem with hybrid discrete variables The dynamic penalty function was constructed. DEA algorithm program with hybrid discrete variables is developed. The computing examples of mechanical optimization design show that this algorithm has no special requirements on the characteristics of optimal designing problems, it has a fairly good universal adaptability and a reliable operation of program with a strong ability of overall convergence and high efficiency.
Optimal Design of the Dynamic Gear Flowmeter
Authors: Jun Zhang , Zhang Cheng , Teng Zhang , Juan Tao , Bin Zhang
Published: April 2012

Multi-objective optimization of the dynamic gear flowmeter was established by using computer software optimization toolbox. We established the objective function with flow pulsation coefficient minimum and smallest volume of the meter as optimized object, by establishing boundary constraint conditions and performance constraint conditions, choosing proper parameters and initial values, and then we can optimize the design parameters by the help of computer software using optimization function. The optimizing methods can greatly improved the design and optimizing efficiency, which can help us to get the optimal design in the shortest time.