bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Analysis of External, Middle and Inner Ear under Loads through Temporomandibular Joint
Authors: Higashimachi Takao , Toriya Ryuzo , Suga Kenichi
Published: June 2012

A structural analysis model including the temporomandibular joint (TMJ), external auditory canal, tympanic membrane, auditory ossicles and cochlea was made. Loads through the TMJ were applied to this model in three-dimensional finite element analysis. It became clear that stress concentration occurred at the lower portion of the external auditory canal, superior tympanic portion (attic), incus long crus, stapes crus and inlet of cochlea. The lower portion of the external auditory canal and attic are favourite sites of cholesteatoma (pearl tumour). Incus long crus and stapes crus are favourite sites of auditory ossicular defects, which are the cause of otitis media. Damage of the cochlea entrance causes high-frequency hearing loss which is age-related.
Simulation of Ultra-Precision Machining for Microstructured Surface Based on FTS
Authors: Zhou Ming , Hu Lin Hua , Dong Guo Jun , Zhang Hai Jun
Published: June 2012

Based on the ultra precision machine tool, using Matlab/Simulink and considering the linear and nonlinear factors of the processing such as environmental vibration, machine movement, servo control technology, work piece material, cutting force and built-up-edge, the simulation system of ultra precision machining for microstructured surface based on fast tool servo (FTS), which integrated machine control system, machine mechanical system and surface generation, was established and verified by processing sinusoidal microstructured surfaces. The experimental results showed the simulation output errors were 15 % or so, and the simulation system could predict the microstructured surface morphology, optimize the processing parameters and provide support for follow up studies.
The Improvement of Removal Function in Local Wet Etching by Using Eccentric Rotation System
Authors: Shen Xin Min , Dai Yi Fan , Peng Wen Qiang , Nagano Mikinori , Yamamura Kazuya
Published: June 2012

Numerical controlled local wet etching is a novel non-contact deterministic figuring method in ultra precision optics fabricating and functional material manufacturing fields, and the cross-sectional shape of the traditional removal spot is a simple cylinder, so the removal function has no adjustability. In order to create more practical and regular removal function, an eccentric rotation system is introduced to improve the LWE system. By controlling the eccentricity, it can achieve varied shapes removal function. When the rotary axis is controlled to a proper eccentricity, the removal function can be close to the Gaussian function. Moreover, the theoretical calculation and experimental validation are coincident and can give the research a steady foundation. The improvement not only can increase the adjustability of the removal function in LWE, but also can expand its applied field and provide reference for other ultra precision machining methods whose removal function does not have circular symmetry.
Remote Internal Diameter Measurement of Ring Gauge Based on a Low-Coherence Tandem Scheme
Authors: Wei Dong , Wu Nan , Takamasu Kiyoshi , Matsumoto Hirokazu
Published: June 2012

A novel internal diameter measurement method based on a low-coherence tandem scheme is firstly demonstrated. From operational analysis, it is understood that a low-coherence tandem scheme can be served for internal diameter evaluation by using a combination of a transmission grating and a ring gauge instead of a classical Michelson interferometer to store and transmit the internal diameter information. As a result of the experiment, in the present experimental environment, diameter measurement of several millimetres with a relative standard uncertainty of several micrometres was performed. Taken together, these results suggest that the present measurement method is expected to be used as a powerful remote internal diameter calibration tool for next-generation calibration network systems.
Experimental Research on Adjusting Cell Position and Orientation with Micro-Fluid
Authors: Zhang Qin , Huang Wei Jun , Su Gang , Aoyama Hisayuki
Published: June 2012

Position and orientation adjustment is an important issue in the micromanipulation of cells. A non-contact method based on micro-fluid for cell position and orientation control was introduced in this paper. The cells were positional fixed by the pressure force of a pair of lined micro-fluids from two tiny tubes. The orientation adjustment was realized by rotating cells in swirls caused by a pair of parallel micro-fluids. By spraying fluctuant micro-fluid, cells orientation can be controlled more precisely. The experiments proved that this non-contact cell position and orientation adjustment method is feasible and secure.
Micro Polishing of Tungsten Carbide Using Magnetostrictive Vibrating Polisher
Authors: Guo Jiang , Suzuki Hirofumi , MORITA Shinya , Yamagata Yutaka , Higuchi Toshiro
Published: June 2012

Micro structured glass lenses are highly required in new fields such as Micro channels, Fresnel lenses for solar panels and Wafer Level Cameras (WLC). The glass lenses are moulded bypress moulding with micro ceramics moulds made of tungsten carbides (WC). In this paper, a new Vibration Assisted Polishing (VAP) method is proposed and developed by using circular vibration of the magnetostrictive vibrating polisher. The polisher is composed of a magnetostrictive vibrator and a small polishing tool, and the small polishing tool is mounted on the head of the magnetostrictive vibrator. The concrete design of the magnetostrictive vibrating polisher is assisted by the finite element method (FEM) and through vibration mode analysis, the 4th mode is selected. It generates a circular vibration trace at a frequency of 9.2 kHz with a radius of 30 μm. The polisher is fixed in a 5-axis (X, Y, Z, B and C) controlled polishing system. Through some fundamental polishing experiments, the shapes of the removal function is acquired and surface roughness is reduced to 9 nm Rz (1 nm Ra).
Laser Trapping Using a Fiber Axicon Microlens
Authors: Taguchi Kozo , Imanaka Shinya
Published: June 2012

In this paper, chemically etched axicon fibre was proposed for laser trapping of micro-objects dispersed in liquid. We fabricated axicon microlenses on a single-mode bare optical fibre using a selective chemical etching technique. The laser beam from a fibre axicon microlens was strongly focused and optical forces were sufficient to move microorganisms and biological cells without physical contact. From the experimental results, it was found that our proposed fibre axicon microlens is a promising tool for cell trapping and the apex angle of the chemically etched fibre axicon microlens is a very important parameter for laser trapping.
Self-Assembly of Functional Particles on Optical Element for Sensitivity Improvement of Biochemical Sensor
Authors: Nishio Manabu , Moronuki Nobuyuki , Tanaka Yasuhiro , Kaneko Arata
Published: June 2012

Self-assembled particles have a wide surface area and thus can improve the sensitivity of biochemical sensors that utilize surface reaction. This paper discusses the self-assembly on a convex lens and condensing characteristic of the fluorescence light emitted from the particles. Silica particles of 1 μm in diameter were assembled on a convex lens and then an immunoassay (antigen-antibody reaction) was carried out on it. It was confirmed that the fluorescence emitted from the particles were condensed at the focal point just the same as in traditional optics. This result can be applied to the improvement of sensitivity and simplification of the system by eliminating fluorescence microscopy.
High Precision Grinding of Large Fresnel Lens Mold
Authors: Furuki Tatsuya , Suzuki Hirofumi , Okada Mutsumi , Yamagata Yutaka , MORITA Shinya
Published: June 2012

Demand for glass Fresnel lenses is increasing in solar panel manufacture in order to increase power efficiency. Glass lenses are usually moulded using a glass moulding method with tungsten carbide moulds. In this study, large Fresnel lens moulds made of tungsten carbide are tested to be ground by a simultaneous 2-axis (Y, Z) controlled grinding method. The resinoid bonded diamond wheel is trued with a rare metal truer to increase the sharpness of the wheel edge. In the grinding test of the tungsten carbide mould, a form accuracy of less than 0.8 μm P-V and surface roughness of 18 nm Rz are obtained, and it is clarified that the proposed grinding method is useful for Fresnel grinding.
Generation and Control of Wide-Field Three-Dimensional Structured Illumination for Advanced Microscopic Imaging
Authors: Usuki Shin , Kanaka Hiroyoshi , Miura Kenjiro Takai
Published: June 2012

In a variety of practical microscopic imaging applications, many industries require not only lateral resolution improvement but also axial resolution improvement. The resolution in optical microscopy is limited by diffraction and determined by the wavelength of the incident light and the numerical aperture (NA) of the objective lens. The diffraction limit is mathematically described by a point spread function in the imaging system, and three-dimensional (3D) point spread functions describe both the lateral and axial resolutions. Thus, it is useful to focus on exceeding this limit and improving the resolution of optical imaging by the spatial control of structured illumination. Structured illumination microscopy is a familiar technique to improve resolution in fluorescent imaging, and it is expected to be applied to industrial applications. Microscopic imaging is convenient, non-destructive, and has a high-throughput performance and compatibility with a number of applications. However, the spatial resolution of conventional light microscopy is limited to wavelength scale and the depth of field is shallow; hence, it is difficult to obtain detailed 3D spatial data of the object to be measured. Here, we propose a new technique for generating and controlling wide-field 3D structured illumination. The technique, based on the 3D interference of multiple laser beams, provides lateral and axial resolution improvement, and a wide 3D field of view. The spatial configuration of the beams was theoretically examined and the optimal incident angle of the multiple beams was confirmed. Numerical simulations using the finite difference time domain (FDTD) method were carried out and confirmed the generation of 3D structured illumination and spatial control of the illumination by using the phase shift of incident beams.
Development of CAPP/CAM System for Ultraprecision Micromachining - Process Planning Considering Setting Error
Authors: Koyama Yasuaki , Nakamoto Keiichi , Takeuchi Yoshimi
Published: June 2012

Ultraprecision machine tools can be expert power together with a CAD/CAM system in generating tool paths. However, CAM systems generally focus on generating NC data. Consequently, operators have to perform process planning by considering the features of machine tools, cutting tools and workpieces. Above all, the setting error may cause interference between the cutting tool and the workpiece, and result in low machining accuracy. Therefore, this study deals with the development of a CAPP/CAM system in ultra-precision micromachining to assist operators in relation to settings. The developed system determines the number of the used control axes of the machine tool, and calculates the required setting accuracy, while preventing tool interference and maintaining the shape error within the tolerance. From the simulation result, it is found that the CAPP/CAM system is effective in producing micro parts easily and accurately.
Tool Deflection Modeling in Ball-End Milling of Sculptured Surface
Authors: Yan Cao Qing , Zhao Jun , Li Yue En , Chen Xiao Xiao
Published: June 2012

The error due to tool deflection is detrimental to machining precision. In order to predict tool deflection more accurately, this paper presents a special three segments cantilever beam model for ball-end tool deflection in sculptured surface milling. Different from the traditional two segments cantilever beam method, the ball-end tool is divided into the shank, the flute and the ball-end parts in this new model. Then the ball-end tool deflection is simulated also by utilizing the finite element software ANSYS 12.0 Workbench to calibrate the accuracy of the tool deflection models. The three segments cantilever beam model for ball-end tool deflection matches better the finite element method (FEM). In the last part of the paper, the sculptured surface machining experimental results show that, the surface precision after tool deflection compensation based on the new three segments cantilever beam model is higer than that based on the two segments cantilever beam model.
Experimental Research on Smooth Surface Polishing Based on the Cluster Magnetorheological Effect
Authors: Yan Jie Wen , Yan Qiu Sheng , Lu Jia Bin , Gao Wei Qiang , Huang Zhi Ying
Published: June 2012

A new planarization polishing method, based on the cluster magnetorheological (MR) effect and using MR fluid to form the flexible polishing pad, is presented in this paper to polish optical glass. To explore the machining characteristic of the viscid and flexible polishing pad based on the cluster MR-effect, some process experiments were conducted to reveal the influence of the machining gap, the speed of the polishing disc and the polishing time on the machining effect. The results indicate that the viscid and flexible polishing pad based on the cluster MR-effect under a strong magnetic field can reduce surface roughness effectively. When the strength of the magnetic field is 2000Gs, and the content of the carbonyl iron is 12%, the surface roughness can be reduced rapidly from the original Ra0.27μm to Ra1.4nm based on the cluster MR-effect.
Trapping of Nano-Particles Using a Near-Field Optical Fiber Probe
Authors: Liu Bing Hui , Yang Li Jun , Wang Yang
Published: June 2012

By employing a generalization of the conservation law for momentum using the finite difference time domain (FDTD) method, the feasibility of using a near-field optical fibre probe to create near-field optical trapping is investigated. Numerical results indicate that the scheme is able to trap nanoparticles with diameters of tens of nanometres in a circular shape with lower laser intensity. Using the built system with a tapered metal-coated fibre probe, 120 nm polystyrene particles are trapped in a multi-circular shape with a minimum size of 400 nm. They are at a resolution of λ/7 (λ: laser wavelength) and d (d: tip diameter of fiber probe), respectively.
Properties of Artificial Lightweight Aggregate by Using Magnetic Separated Bottom Ash from Coal Power Plant
Authors: Kim Yoo Taek , Jang Chang Sub , Choi Yun Jae
Published: June 2012

This study was conducted to evaluate the feasibility of using bottom ash after magnetic separation and dredged soil from the coal power plants as raw materials for artificial lightweight aggregate (ALA). The dependence of composition and sintering temperature on physical properties of ALA was investigated. Fe compounds play an important role in the bloating reaction, thus specimens containing more ferrous materials such as Fe3O4 are more easily bloated. Both black core region and bloating phenomenon were increased with an increase in the contents of dredged soil. Specimens made use of MBA(Magnetic separated bottom ash which has magnetic components) showed lower bulk density than those of NMBA(non-magnetic separated bottom ash which has much less ferrous materials. It was confirmed that MBA could be used as an effective raw material for making ALA having low density because the ferrous components in it act as bloating agents.
Thermoelectric Properties of Manganese Monosilicide Synthesized by Mechanical Alloying Process
Authors: Choi Moon Kwan , Lee Woong Jae , Kim Il Ho , Lee Young Geun , Kweon Soon Yong , Yoon Man Soon , Ur Soon Chul
Published: June 2012

Manganese silicide is one of the potential thermoelectric materials for high temperature application. As a fundamental investigation on these materials group, manganese monosilicides were synthesized by the mechanical alloying of stoichiometric elemental powder compositions, and the as-milled powders were consolidate by vacuum hot pressing. Phase transformation and microstructure evolution during mechanical alloying and hot consolidation were investigated using XRD and SEM. Near single phase of monosilicides were successfully produced in this process. Thermoelectric properties as a function of temperature were evaluated in terms of Seebeek coefficient, electrical resistivity, thermal conductivity and the figure of merit for the hot pressed specimens. Mechanically alloyed manganese monosilicide, MnSi, appeared to have a potential as a thermoelectric material in this study.
Effect of N2 Addition on Microstructure and Properties of SAF 2507 Duplex Stainless Steels GTAW Welded Joint
Authors: Du Dong Fang , Liu Jie , Li Guo Ping , Liu Jin Ming
Published: June 2012

In this paper, SAF2507 duplex stainless steel (DSS) was welded by GTAW with ER2594 as filler wire, and Ar + N2 as shielding gas. The results show that, with increasing the content of N2 in the shielding gas, the amount of austenite in weld metal increase, the micro-hardness drops and impact energy increases; the use of Ar +2 ~ 3% N2 welding parameters, the microstructure and mechanical properties of welded joints are the best, the austenitic rates and impact energy of weld metals are 51%~53% and 75~88 J, respectively, and the welding process is easy to control; when the content of N2 reach 5%, the impact energy of weld metal decreases obviously and the welding arc is unstable.
Compressive Strength Evaluation of SCR Catalyst Recycled Al-Dross
Authors: Bae Min A , Kim Hong Dae , Kim Kwang Ho , Lee Man Sig
Published: June 2012

Aluminum dross is forms at the surface of the molten metal as the latter reacts with the furnace atmosphere and it was an unavoidable by-product of the aluminum production process. However, it has not been sufficiently recycled yet. Approximately 95% of the Al dross was land filled without innocent treatment. Therefore, Al-dross is positively necessary to recycling. The purpose of this study is to investigate the compressive strength of Selective Catalyst Reduction (SCR) prepares using recycled Al-dross and compared commercial SCR catalyst. Recycled Al-dross was as support material to increase strength. As to experimental procedures, Al dross was classified according to its size. The recycled Al dross was made into SCR catalyst by mixing with WO3, V2O5, and TiO2. After V2O5-WO3-TiO2-Al2O3 SCR strength was measured by Universal Testing Machine (UTM). And then NOx removal activity of V2O5-WO3-TiO2-Al2O3 SCR and commercial SCR catalyst were observed by MR(Micro-Reactor).
Prediction of Fine Blanking Tool Deformation to Produce Multiple Turbocharger Vane Levers with Stainless Steel
Authors: Kim Jong Deok , Kang Jeong Jin
Published: June 2012

The use of turbochargers improves engine power, reduces the rate of fuel consumption. The vane lever is an important part of a turbocharger that regulates the volume of hot exhaust gas. Until now it has been produced by a 4 cavity fine blanking tool, but it requires the use of an 8 cavity fine blanking tool for better productivity. In this paper, we conducted structural simulation of an 8 cavity fine blanking tool and predicted the deformation of fine blanking tool elements. The maximum vertical deformation of the die was 0.01222mm and the maximum horizontal deformation of the die was 0.00096mm. This deformation led to a clearance change in the 8 cavity fine blanking tool. According to the simulation results, the calculated clearance was increased to a maximum of 45.9%, decreased to a minimum of 49.0%. Through the fine blanking experiment with the manufactured 8 cavity fine blanking tool, we demonstrated that 8 vane levers could be simultaneously produced by the 8 cavity fine blanking tool.
Preparation and Characterization of KGM/CaCO3 Composite Films
Authors: Chen Yan , Zhang Hong Ping , Lin Xiao Yan , Chen Ming Qi , Jiang Yong Man
Published: June 2012

The influences of processing parameters on the tensile strength (TS) of KGM/CaCO3composite films (KCaCF) were investigated through orthogonal experiment method. Calcium carbonate and KCaCF were characterized, respectively, by XRD, laser diffraction particle size analyzer, zeta potential analyzer and SEM. The results showed that micron-sized calcite CaCO3crystals with-16.4 mv of Zeta potential were synthesized. Calcium carbonate dispersion was blended with KGM to fabricate KCaCF. The mass of CaCO3, KGM and swelling time affected TS of composite films differently, but didnt reach the significant level (p>0.05). The optimal preparation process for KCaCF is that 5.0% (wt) of KGM powder is added into the dispersion with 2.0% (wt) of CaCO3, swelling for 1.0 hour at 50 °C and pH 8.0 and then poured onto plate and dried at 50 °C for 15 h.
Microstructure and Mechanical Properties of Al/Cu Composite Produced by Hydrostatic Extrusion during Isothermal Aging
Authors: Jeong Ha Guk , Lee Jong Beom
Published: June 2012

In this study, Al/Cu composite was produced by hydrostatic extrusion process at 523 K. Mechanical and electrical properties of Al/Cu composite were investigated during isothermal aging. Microstructure observation and composition analysis of the interface was carried out scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. Three kinds of intermetallic composites are observed and they have increased in size as a function of annealing process. Their growth brings about the decrease in the hardness Al/Cu composite.
Effect of Annealing Process on Mechanical Properties and Texture Changes of AZ31 Mg Alloy Sheets
Authors: Bang Ho Jun , Jeong Ha Guk , Lee Jong Beom
Published: June 2012

Mg alloy sheets exhibit the yield strength of 280 MPa and elongation of 18 % by rolling at 423 K. Elongation of Mg alloy sheets was improved up to 35 % when the sample was annealed at 673 K for 10 min. From the observation of microstructure, recrystallization and grain growth have happened during annealing processes. The intensity of 0002 pole figure increases slightly as a function of annealing temperature.
Porosity Measurement of Porous Copper by Unidirectional Solidification
Authors: Du Hao , Lao Yuan Xia , Qi Jian Zhong , Xiong Tian Ying
Published: June 2012

Generally, there are two ways available for porosity measurement of porous metals. One is by calculating density ratio of a porous metal and a corresponding non-porous metal, called as relative density method. The other is by counting the percentage of pores on cross section of a porous metal, called as image analysis method. In this work, both methods were employed for lotus-type porous copper on porosity measurement. The effects of several parameters in both methods on porosity values of the porous copper are reported and discussed. The relative density method is recommended as porosity by this method is more reliable for the porous copper.
Effects of β-Si3N4 Seeds Addition on Microstructure and Mechanical Properties of Porous Si3N4 Ceramics
Authors: Yu Fang Li , Bai Yu , Du Jun , Yu Ping Ping , Wang Jian Zhi , Yang Jian Feng
Published: June 2012

Porous Si3N4 ceramics were prepared by conventional sintering method with the initial Si3N4 powder added different amounts of β-Si3N4 seeds and 5 wt.% Y2O3. The porosity, density and flexural strength were tested by Archimedes and three-point bending methods, respectively. Microstructure of porous Si3N4 ceramics was studied by scanning electron microscopy. The results showed that the fibrous β-Si3N4 grains developed in the bimodal porous microstructure and the average aspect ratio of 6.42 by adjusting the β-Si3N4 seeds content up to 3 wt.%. Under the porosity of about 42%, the flexural strength of the materials could reached 315.98 MPa.
Effect of Size and Stress Field on Electronic Properties of ZnO Nanowires
Authors: He Cheng , Zhang Wen Xue
Published: June 2012

The effects of external stress fieldfon band gapEg(D,f) of ZnO nanowires (NWs) in a diameter range ofD= 0.6 - 2.0 nm are investigated using first-principles density-function theory for the future application as nanogenerators. It is shown that theEg(D,0) values decreases with the increasing diameter of ZnO NWs without the stress field. Moreover,Eg(D, f) decreases with increasing offdue to the rapid drop of conduction band maximum of ZnO NWs whenDis constant. These findings imply thatEg(D,f) functions of ZnO NWs can be modulated by manipulatingDandf, which may be help for design of ZnO nanogenerators with a higher generation output voltage.
Synthesis of Sn4+ Doped TiO2 Nanotube and its Photocatalytic Activity
Authors: Dong Hong Ying , Ren Yan Ping , Huang Kai Ming , He Wei Yan , Ma Wen
Published: June 2012

The PVP+Ti (OC4H9)4+SnCl4·5H2O/sesame oil composite fibers were successfully prepared by a sol-gel method combined with a coaxial electrospinning technique. The Sn4+/TiO2 nanotubes were obtained by calcining the above-mentioned composite fibers and characterized by XRD and TEM. XRD results show that increasing reaction temperature facilitates to form a stable phase. TEM results show that the Sn4+/TiO2 nanotubes have smooth surface with wall thickness of ~120 nm and are composed of small particles of ~5 nm. The photocatalytic activity of Sn4+/TiO2 nanotubes was investigated. The photodegradation efficiency of Sn4+/TiO2 nanotubes decreases in UV region but increases in visible light region. The photocatalytic properties of three 0.52at% Sn4+/TiO2 nanomaterials with different morphologies were also evaluated. The photodegradation efficiencies of Sn4+/TiO2 nanopowers, Sn4+/TiO2 nanofibers and Sn4+/TiO2 nanotubes increase in visible light region in sequence. In summary, chemical modification by doping Sn4+ and morphology changing for TiO2 can improve its photocatalytic activity in visible light region significantly.
Preparation of Porous Alumina Powder Using Sol Containing Trehalose Dihydrate
Authors: Miki Takeshi , Tai Yutaka
Published: June 2012

To obtain alumina powder with large surface area, the precursor sol was prepared by hydrolysis of aluminum isopropoxide and then mixing with trehalose dihydrate. The porous alumina powders were prepared by drying and calcination at 500-900 °C. The specific surface area went up to over 340 m2/g in the alumina powder calcined at 500 °C. The mean pore diameter of the alumina powder was increased by the addition of treahalose dihydrate. The porous alumina powder was successfully prepared by the addition of trehalose dihydrate to the precursor sol.
Research on Production of Bluecoke with Low Temperature Carbonization Process
Authors: Wu Lei , Zhou Jun , Lan Xin Zhe , Zhao Xi Cheng , Song Yong Hui , Hua Jian She
Published: June 2012

Bluecoke is a new type carbon product that prepared by low temperature carbonization process, which take lignite, long flame coal, not sticky and weak glue coal as raw material. At the same time tar and coke oven gas as by-products can be obtained. Two new technologies of Bluecoke production were introduced based on summary of way of producing Bluecoke by low metamorphic coal, namely the rich oxygen carbonization and the microwave carbonization. Both ways have their advantages and disadvantages. By contrast, the quality of coke and the content of valid gas are better using microwave carbonization, which to follow-up industry chains development significantly.
Low-Temperature and Rapid Fabrication of Bulk Nano-TiO2 Ceramic
Authors: Liu Gui Wu , Jian Wen Zheng , Jin Hai Yun , Shi Zhong Qi , Qiao Guan Jun
Published: June 2012

A self-made sectional die made of high-performance graphite, SiC ceramic and Ni-based superalloy was firstly designed and developed. The TiO2 ceramic, with original TiO2 powders of average particle size ~25 nm and 80 wt.% anatase + 20 wt.% rutile, was fabricated by plasma activated sintering (PAS) at 500600 °C for 3 min under applied uniaxial pressure of 2001000 MPa using the sectional die. The influences of sintering temperature and applied pressure on the density, phase transformation and grain growth of the TiO2 ceramic were investigated. The results showed that the sintering temperature and applied pressure played key roles in determining the relative density, phase composition and grain size of the TiO2 ceramic. The relative density and grain size increased and the anatase phase transformed into the rutile phase slowly or quickly as the sintering temperature or the applied pressure increased. In particular, the increase of sintering temperature was very advantageous to the phase transformation, and the increase of applied pressure was quite effective to inhabit the grain growth. All the averaged grain sizes of TiO2 ceramics were less than 100 nm in the present experimental conditions. Moreover, the relative density of the sintered ceramic were over 95% when the optimized sintering parameters were 600 °C × 500MPa or 500 °C × 1000MPa. The TiO2 ceramics were composed of only the rutile phase when the applied pressure and the sintering temperature were not less than 300 MPa and 550 °C, respectively.
Treatment Performance of Low Strength Electric Wastewater Using Solid-Advanced Oxidation Processes
Authors: Kim Jong Oh , Lee Jun Su , Chung Jin Wook
Published: June 2012

This study aims to show the catalyst effect for the removal of low molecular weight organics in semiconductor wastewater. To investigate and compare the removal efficiency, experiments were conducted to change in mixing ratio of catalyst with activated carbon. As a result, optimal condition for the removal of acetone and IPA of the catalyst ratio was (Cu+Fe) = 8:2 and (Fe+Al)=9:1 with activated carbon at pH 3. Acetone was removed above 70% and isopropyl alcohol (IPA) was almost removed 100% in the pH 3, pH 4 except for pH 7 condition, the remaining acetone concentration was 51.4 ppb in IPA solution, these results is attributed that IPA transformed to acetone after the reaction. Solid-advanced oxidation processes was believed to be an effective method to treat the low adsorbability of organics contained in electric wastewater.
Preparation and Performance of LiFePO4/C Using Fe2O3 as Starting Material
Authors: Ren Qiang , Yang Yang , Wu Xiu Lan
Published: June 2012

To improve the electrochemical performance of LiFePO4, LiFePO4/C composite materials were prepared by solid-state synthesis method with Fe2O3 as one of the starting materials. The phase composition, microstructure and morphology of samples were determined by X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical performance of samples were characterized by constant current charge-discharge method. The results show that the prepared samples have the single phase, and the carbon coating lead to no change of the crystal structure of LiFePO4. The sample with carbon content of 10wt% shows the best electrochemical properties. Its initial discharge capacity is 144.6 mA·h /g at 0.2C rate. After 30 cycles the capacity remains 131.4 mA·h /g, and the capacity retention rate is 91%.
A Brief Review about Surface Treatment of Magnesium Alloys
Authors: Bai Yu , Yu Fang Li , Du Jun , Wang Wen Xian , Cui Ze Qin , Han Zhi Hai , Yang Jian Feng
Published: June 2012

Due to the low density and high specific strength, magnesium and its alloys have been extensively used in the automobile and aerospace applications, where the weight reduction is critical. However, they are highly prone to corrosion, which has greatly limited their application in the automotive and aerospace industries. This paper briefly reviews the technologies for improving the corrosion and wear resistance of magnesium alloys and finds that the widespread application of magnesium alloys is still limited by the lack of proper protective coatings. Therefore, there is still a need to explore new materials and methods for the effective protection of magnesium and its alloys.
Effect of Calcination of the Raw Materials on the Microstructure and Electrical Properties of ZnO-Based Linear Resistance Ceramics
Authors: Zhu Jian Feng , Zhou Yong
Published: June 2012

ZnO-based linear resistance ceramics were fabricated by the conventional ceramic method. The effect of calcination of the raw materials on the microstructure and electrical properties was investigated in detail. The results show that the electrical properties, such as resistivity, nonlinear coefficient and resistance temperature coefficient, have been obviously influenced by the calcining process. The optimal samples fabricated with the materials calcinated for twice possess the highest stabilization of resistivity. Meanwhile, the resistance temperature coefficient is improved by 30%, and the nonlinear coefficient of voltage decreases to 1.16, decreased by 20.7%.
Effect of Ti, Al and Cu Addition on Structural Evolution and Phase Constitution of FeCoNi System Equimolar Alloys
Authors: Wang Xiao , Xie Hui , Jia Lei , Lu Zhen Lin
Published: June 2012

FeCoNi system equimolar alloys were fabricated by a vacuum arc melting. The phase constitution of FeCoNi system alloys was determined by XRD analysis and the microstructure was observed by OM. The comprehensive atomic radius δ, the mixing enthalpy ΔHmix and the mixing entropy ΔSmix of alloys were also calculated according to relevant equations. The results show that the addition of Ti, Al and Cu has an obvious influence on the microstructure and phase constitution of FeCoNi system equimolar alloys. Single Ti addition resulted in almost entire solid solution with a typical dendrite growth character and a little unknown phase. However, further addition of Al, Cu or Al+Cu into the FeCoNiTi equimolar alloys led to the occurrence of an entire solution phase with dendrite, coarse dendrite, and rosette dendrite respectively. Such a phenomena suggested that the mixing entropy caused by the increase of components number rather than the comprehensive atomic radius between the elements or the mixing enthalpy of the alloy systems might be responsible for the formation of almost entire solid solution in FeCoNi system equimolar alloys.
A Study on Reaction Bonded Ceramics Fabricated by Silicon Infiltration to B4C Preforms
Authors: Liu Rong Zhen , Duan Qing Wen , Gu Wen Wei , Jin Hai Yun , Xu Shao Chun , Yang Jian Feng
Published: June 2012

Silicon was infiltrated into B4C preforms to fabricate B4C based composites ceramics at 1600 °C under vacuum circumstance. In this paper, silicon infiltration process was discussed by theoretical calculation. The volume expansion caused by reactions between silicon and boron carbide was about 89.1% from the calculation. In our study, the maximum density of B4C preform for the infiltration of silicon was about 1.5g/cm3 which was larger than theoretical result. The results of mechanical behavior showed that B4C based composites had excellent mechanical properties with a density lower than 2.6g/cm3, Vickers-hardness of this material was 27.2GPa, and this material showed a flexural strength of 349MPa and fracture toughness of 3.8 MPa*m1/2.
Fabrication of Porous SiC/SiAlON Composites Using Semi Coke and Fly Ash as Raw Material
Authors: Duan Qing Wen , Liu Rong Zhen , Jin Hai Yun , Yang Jian Feng , Jin Zhi Hao
Published: June 2012

Porous SiC/SiAlON ceramics were fabricated by carbothermal reduction method from raw materials of fly ash and semi coke in nitrogen atmosphere. The results showed that composites were composed by multi-structure of SiC, Ca-SiAlON and AlN phases. With the increase of semi coke contents, the contents of Ca-Sialon increased. The fracture mode of this material was intergranular. The results also showed that micro area hereditary of semi coke particles was observed in the morphology of this material. The morphology of this material was composed by nanosized SiC and plate like Ca-SiAlON. The median pore diameter was affected by the contents of semi coke and increased with the increase of semi coke content.
Prediction of the Flow Stress of a High Alloyed Austenitic Stainless Steel Using Artificial Neural Network
Authors: Zhang Zhao Hui , Yan Dong Na , Ju Jian Tao , Han Ying
Published: June 2012

The high temperature flow behavior of as-cast 904L austenitic stainless steel was studied using artificial neural network (ANN). Isothermal compression tests were carried out at the temperature range of 1000°C to 1200°C and strain rate range of 0.01 to 10s1. Based on the experimental flow stress data, an ANN model for the constitutive relationship between flow stress and strain, strain rate and deformation temperature was constructed by back-propagation (BP) method. Three layer structured network with one hidden layer and nine hidden neurons was trained and the normalization method was employed in training process to avoid over fitting. Modeling results show that the developed ANN model exhibits good performance for predicting the flow stresses of the 904L steel. Therefore, it can be used to reflect the hot deformation behavior in a wide working window.
Modified Distillers' Grains by Microwave-Assisted Hydrolysis for Cu2+ Adsorption from Aqueous Solution
Authors: Su Rong Rong , Chen Yan , Zhou Yan Fang , Lin Xiao Yan , Feng Juan , Rao Jia Quan
Published: June 2012

Sodium hydroxide was used to modify distillers' grains (DG) assisted by microwave in order to comprehensive utilization of distillers' grains (DG). The property of distillers' grains (DG) before and after modified was investigated as well as modified conditions. 0.1g of different modified distillers' grains (MDG) was, respectively, used as the absorbents for removal of heavy metal Cu2+ ions from aqueous solution at pH 7 and 25°C for 10h. The results show that the modification temperature, time and liquid to solid ratio has little effect on absorption of the modified distillers' grains (MDG) for Cu2+ except for concentration of alkali, 5% (wt/v) is the optimum concentration. 5% (wt/v) of the alkali concentration, the hydrolysis temperature of 20°C and the hydrolysis time of 30min and the ratio of liquid to solid ratio of 5:1 were, respectively, used as the optimized conditions to modified distillers' grains (MDG). The removal efficiency of the modified distillers' grains (MDG) for Cu2+ (20.00 mg·L1) is 98.11% under optimized conditions.
Fabrication of Nanosheet-Assembled Hierarchical AlOOH and γ-Al2O3 Microspheres and its Application in Water Purification
Authors: He Xuan Meng , Li Guang Jun , Liu Hui , Li Jun Qi
Published: June 2012

Hierarchical AlOOH microspheres assembled from nanosheets were successfully synthesized via a microwave hydrothermal method, by using AlCl3·6H2O and NaOH as raw materials and cetyltrimethyl ammonium bromide (CTAB) as a surfactant. Thermal decomposition of the AlOOH precursor at 500°C for 2h produced γ-Al2O3 that maintained the precursors morphology. The products were well characterized by SEM, TEM and XRD. Finally, both hierarchical AlOOH and γ-Al2O3 microspheres were used to adsorb Congo red from a water solution. The experimental results show that hierarchical AlOOH microspheres with the diameter about 1μm are assembled from nanosheets with average thickness of about 20nm. The morphology of the obtained γ-Al2O3 microspheres is well preserved, and nanometer-size holes appear on the surface of the nanosheets. Both AlOOH and γ-Al2O3 microspheres are very effective in the removal of Congo red pollutant from waste water which may be attributed to their textured microstructure and high specific surface area.
Synthesis of Glycerol Carbonate from Biomass Glycerol: Focus on the Calcination Temperature
Authors: Baek Jae Ho , Ryu Young Bok , Kim Myung Hwan , Moon Myung Jun , Lee Man Sig
Published: June 2012

We carried out a reaction in which glycerol carbonate was synthesized by using glycerol and urea. The physical properties of the prepared catalysts were investigated by BET surface area, X-ray diffraction, temperature programmed desorption, and Field-emission scanning electron microcopy. In addition, we confirmed the conversion of the glycerol and the yield of the glycerol carbonate according to calcination temperature. From XRD results, the crystalline of prepared ZnAl2O4 was slowly increased with an increasing of the calcination temperature. When the calcination temperature of ZnAl2O4 was 500 , the conversion of the glycerol was 74.4% and the yield of the glycerol carbonate was 73.3%. The conversion of the glycerol and the yield of the glycerol carbonate can be obtained higher when acid/base ratio is approx. 1. From this result, we may conclude that the acid & base site density and ratio of catalysts were very important parameters in the synthesis of glycerol carbonate from urea and glycerol.
Dye Sensitized Solar Cells Based on ZnO Nanorod/TiO2 Nanoparticle Composite Films
Authors: Tong Hui , Inada Miki , Tanaka Yumi , Enomoto Naoya , Hojo Junichi
Published: June 2012

ZnO nanorod/TiO2 nanoparticle composite films were prepared by a sol-gel method, in which the slurry of TiO2 nanoparticles (NPs) were penetrated into ZnO nanorod arrays. The agglomerate size of TiO2 NPs was controlled with tetraethylammonium hydroxide. Lowering ZnO nanorod array density was an effective way to fill TiO2 NPs in the space of ZnO nanorod array. The presence of ZnO and TiO2 was confirmed by scanning electron microscopy and X-ray diffraction. Triblock copolymer (P123) was added as a template agent to obtain high specific surface area, and the solar cell performance was improved. However, the viscosity of the TiO2 slurry was increased by addition of P123, and TiO2 content in the composite film was reduced. Low concentration TiO2 slurry was preferable to be penetrated into ZnO nanorod array and solar cell performance was further improved.
A Study on Fabrication, Dispersion and Surface Coating of Nanocarbon for MgO-C Refractories
Authors: Jeong Kwang Jin , Son Jeong Hun , Lee Seung Seok , Bae Dong Sik
Published: June 2012

Spherical carbon nanoparticles were synthesized by sol-gel polymerization of resorcinol and formaldehyde in the presence of CTAB(cetyltrimethyl ammonium bromide) and subsequent carbonization at 900 in N2 atmosphere. It is found that the amount of CTAB, water and catalyst showed a significant impact on the morphology and size of carbon nanoparticles. The magnesia-carbon (MgO-C) bricks containing 1~4 wt% nanocarbon were prepared by adding various types of carbon black (CB), multi walled carbon nanotubes (CNT) and synthesized nanocarbon. The mechanical properties, oxidation resistance and corrosion resistance of the MgO-C brick in which the nanocarbon is added was investigated. The MgO-C refractories were characterized by Field Emission Scanning Electron Microscope (FE-SEM, MIRA II LMH), Cold Crush Strength (CCS).
Synthesis and Characterization of Sulfonated Poly(diphenyl ether ketone sulfone)s Containing Dibenzoylbenzene Moiety for Proton Exchange Membrane Fuel Cell
Authors: Hossain Md. Awlad , Lim Young Don , Seo Dong Wan , Lee Soon Ho , Lee Hyun Chul , Jang Ho Hyoun , Islam Md. Monirul , Kim Whan Gi
Published: June 2012

Sulfonated poly (diphenyl ether ketone sulfone) s, SPDPEKSs were successfully synthesized for proton exchange membranes (PEMs). Poly (diphenyl ether ketone sulfone) s, PDPEKSs were prepared by the polycondensation of 4,4'-sulfonyldiphenol with 1,2-bis (4-fluorobenzoyl)-3,6-diphenylbenzene (BFBDPB) and 4-fluorophenylsulfone respectively, at 210 °C using anhydrous potassium carbonate as catalyst in sulfolane. PDPEKSs were followed by sulfonation using chlorosulfonic acid and concentrated sulfuric acid at two step reactions. Different contents of sulfonated unit of SPDPEKS (25, 35, 45 mol% of BFBDPB) were studied by FT-IR, 1H NMR spectroscopy, and thermogravimetric analysis (TGA). The ion exchange capacity (IEC), water uptake and proton conductivity of SPDPEKS were evaluated with increase of degree of sulfonation.
Inspection of the TFT Devices Using the Low-Energy Electron Beam Emitted from the Microcolumn
Authors: Oh Tae Sik , Ahn Seung Joon , Ahn Seong Joon , Kim Dae Wook , Kim Ho Seob
Published: June 2012

The inspection of the TFT device for the LCD panel has been usually carried out by the large-scale electron column where the kinetic energy of the electron beam is higher than 10 kV, which has many disadvantages for the inspection. In this work, we replaced the bulky electron column with a tiny microcolumn and carried out the inspection of the TFT device. The result shows that the low-energy e-beam inspection can clearly observe the physical defects of the devices and also identify the abnormal electrical behavior caused by the defects in the device.
Fast Inspection of Non-Visual Defects in the Wafer Surface Using Two Low-Energy E-Beam Sources
Authors: Ahn Seong Joon , Oh Tae Sik , Kim Dae Wook , Kim Ho Seob , Ahn Seung Joon
Published: June 2012

Although the electron-beam (e-beam) inspection can find the non-visual defects in the semiconductor devices under the fabrication procedure, it has a problem of low inspection speed. To resolve this problem, in this work, we have demonstrate the low-energy e-beam inspection using a tiny microcolumn as the e-beam source. The experimental result indicates that the non-visual defects in the wafer can be easily identified by measuring the e-beam current at the backside of the wafer. Since it is not difficult to make the multiple e-beam sources by packing many microcolumns, we can enhance the inspection many times by using the microcolumn e-beam sources.
The Effects of Catchment Materials and Treatment Train on Rainwater Quality in a Rainwater Harvesting System
Authors: Mun Jung Soo , Kim Ree Ho , Han Moo Young
Published: June 2012

Recently the interest on rainwater harvesting has been increasing and the installation of rainwater harvesting system (RWHS) has been spread. However, little information is available about influences of catchment materials and system configurations on rainwater quality. This study was performed to examine the rainwater quality according to catchment conditions and system configurations in a roof RWHS. The catchment area of the building #39 in Seoul National University, Seoul, South Korea is 3,652 m2 and consists of the concrete roof, roof garden and marble terrace. RWHS provides water for toilet flushing through the supply facilities. Water quality was analyzed at each catchment area and facilities of the system during rainfall. The pH, EC, turbidity and SS of runoff from the marble terrace showed higher than those of runoff from roof and roof garden. As influences of runoff from terrace and roof garden, turbidity, SS and EC showed high concentration in early part of the RWHS, but those were lower as passing through the system. Catchment conditions should be considered carefully in design of RWHS. Furthermore, the change of water quality due to the arrangement and configurations of the system should be reflected to evaluate water quality in RWHS.
Study on the Rheological Properties of LLDPE/CaCO3 Plasticized with the Fatty Acid Extracted from Hogwash Oil
Authors: Yun Chao Le , Luo Xue Gang , Lin Xiao Yan , Zhang Hong Ping , Li Ji Wei , He Pan
Published: June 2012

The reaction in linear low density polyethylene/Calcium carbonate (LLDPE/CaCO3) melting blend system with the presence of fatty acid extracted from Hogwash oil (HWOFA) was investigated by means of a Torque Rheometer during compounding. The characteristics of the products were evaluated by DSC and Universal Testing machine. The results showed that the maximum torque and equilibrium torque of the LLDPE/CaCO3 blends with addition of 15wt% HWOFA decreased respectively by 23.83% and 27.55% which were lower than that without HWOFA. The tensile strength decreased by 23.94%and the elongation at break increased by 16.88%. The compatibility became poor with addition of more than 15wt% HWOFA. The above results indicated that the fatty acid extracted from Hogwash oil can be used as a lower-cost plasticizer, which provides a new method of utilization of Hogwash oil.