bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Property and Microstructure in HAZ of High-Strength Abrasion-Resistant Steel
Authors: Niu Ji Tai , Huang Wei Feng , Xu Jing Jun , Guo Yong Liang
Published: March 2009

In this paper, a type of the high-strength abrasion-resistant steel-NM360 has been studied with the aid of the modern physical simulation technology to solve the problem of its poor weldability. In the experiment, the welding thermal cycles under different cooling conditions with the peak heating temperature of 1320oC were simulated via the Gleeble-1500D thermal/mechanical simulator. The SH-CCT diagram of NM360 has been established by investigating the microstructure transformation course and the hardness of the welded heat-affected zone (HAZ) near fusion line during different cooling process. Moreover, the impact toughness and fracture in HAZ with different cooling rate have been studied. The established SH-CCT diagram and impact toughness in HAZ provide the referential experimental basis for selecting proper welding parameters. At last, the welding parameters for NM360 steel are determined with the aid of nomography of carbon dioxide gas shielded arc welding and empirical formula.
Mechanical Properties of Hip Joint Heads Made of the Dispersion Ceramic - Alumina Toughened Zirconia
Authors: Begand Sabine , Oberbach Thomas , Glien Wilfried
Published: March 2009

For orthopaedic applications an Alumina Toughened Zirconia Ceramic was tested regarding its mechanical behaviour. We observed a marked higher strength compared to the requirements according to FDA guidelines and a significantly higher strength compared to alumina ceramic despite of 15 % decreased fatigue burst strength. The wear resistance after ring-on-disc method is significantly improved comparing to standard Al2O3/Al2O3 pairings. It means the application of endoprosthetic components made of ATZ-ceramic offers more safety and reliability.
Performance of Osteoinductive Biphasic Calcium-Phosphate Ceramic in a Critical-sized Defect in Goats
Authors: Habibovic Pamela , van den Doel Mirella , van Blitterswijk Clemens A. , de Groot K.
Published: March 2009

Osteoinductive biomaterials are able of inducing bone formation at ectopic, i.e. extraskeletal implantation sites. It is, however, important to investigate whether osteoinductive biomaterials perform better when implanted orthotopically as well, in particular in clinically relevant criticalsized defects. In this study, an osteoinductive and a non-osteoinductive biphasic calcium-phosphate (BCP) ceramic were compared in a critical-sized iliac wing defect that allows for paired comparison. After 12 weeks of implantation in the critical-sized defect, the osteoinductive BCP1150 ceramic showed significantly more bone than the non-osteoinductive BCP1300 ceramic. In addition, the analysis of fluorochrome markers, which were administered to the animals 4, 6 and 8 weeks after implantation in order to visualize the bone growth dynamics, showed an earlier start of bone formation in BCP1150 as compared to BCP1300. Significantly better performance of osteoinductive ceramic in a critical-sized orthotopic defect in a large animal model in comparison to the non-osteoinductive ceramic suggests osteoinduction to be clinically relevant.
Optimum Conditions for Superosteoconductivity of Polarized Hydroxyapatite Ceramics
Authors: Kobayashi Takayuki , Nakamura Satoshi , Yamashita Kimihiro
Published: March 2009

Surface charges of biomaterials are recognized as one of the important factors to determine cell and tissue responses. The HA ceramics polarized at various temperatures were estimated by implantation tests. The HA ceramic samples with the polarization treatment at temperature ranging from 250 to 500°C
were implanted into bones. These phenomena were observed regard less the polarization temperature. It was obvious that the negatively chargedsurfaces acquired the excellent osteoconductivity at the polarization
temperature from 250 to 500°C. The similarity of the tissue reactions implied that the variation of stored charges was within a tolerance of an effective stimulation and that the enhancement mechanism of the osteoconduction had not a linear sensibility of electrostatic charges.
Titanium Oxide Layer with Micro and Nano Tubes on Titanium Substrate
Authors: Hwang Jae Sun , Lee Sang Bae , Oh Keun Taek , Kim Kyoung Nam , Kim Kwang Mahn
Published: March 2009

The formation of titanium oxide layer with micro and nanotube arrays on titanium substrate was investigated by grit-blasting and anodic oxidation treatment. Micro rough surface can be formed by grit-blasting and nanotube arrays can be formed by anodic oxidation. The morphology of the hybrid surface(micro and nanotube arrays surface) can be affected by the mechanical conditions (grit size, grit material, blasting pressure, nozzle tip of blasting machine, distance nozzle tip and specimen, blasting time) and electrochemical conditions (applied potential,
electrolyte concentration and anodizing time) used. Such micro pore and nanotube arrays of titanium oxide can be useful for well-adhered bioactive surface layer on Ti implant metals for orthopedic and dental implants, as well as for photo catalysts
and other sensor applications.
Emulsion Technique Preparation of Nano-HA/PMMA Composites and In Vitro Evaluation
Authors: Hu Quan , Liu Hui Bin , Weng Wen Jian , Cheng Kui , Song Chen Lu , Du Pi Yi , Zhao Gao Ling , Shen Ge , Wang Jian Xun , Han Gao Rong
Published: March 2009

Nano-sized hydroxyapatite (HA) chloroform suspensions were firstly prepared by
reactions in an emulsion system of Ca(OH)2-H3PO4-chloroform-lecithin, then, HA/PMMA composites with well dispersed HA could be obtained by adding PMMA into the suspension. The residual water in the HA suspension could lead to a porous surface which demonstrated better bioactivity in in vitro test. The residual water could cause HA particles to exist on pore walls during the composite formation, resulting in the increase of the HA amount per unit surfac
A Complementary Biocompatibility Evaluation of Plasma Sprayed Dentine (DHA) and Enamel Derived Hydroxyapatite (EHA) Using Fibroblasts
Authors: Oktar Faik N. , Zdrentu Livia E. , Petrescu S. , Valério Patricia , Ozyegin L.S. , Peker Ismail
Published: March 2009

Hydroxyapatite (HA) material, collected from human tooth, was calcined and then
separated very easily to enamel HA (EHA) and dentine HA (DHA). The EHA and DHA were plasma sprayed on pre-prepared titanium implants. HeLa (a lineage malignant fibroblast cell) and primary fibroblast cells cell lines were used in this study. The results using fibroblasts from primary culture are interesting since the cells did not die or became apoptotic. However, this does not mean
that the present method reveals the complete biocompatibility of the tested HA material. This study aimed to investigate if fibroblasts with fluorescent tests could be used as a secondary evaluation method for biocompatibity fibroblasts cell culture studies prior to osteoblasts cell culture.
Crystallites Size and Changes in Mineral Phase of Bone with Age and Type of Bone
Authors: Bertazzo S. , Bertran Celso A.
Published: March 2009

In this work, some modifications that occur in crystallites that compose the mineral phase of bone throughout the lives of animals were studied by X-ray diffractometry. The Debye-Scherrer equation was applied to the diffractograms, allowing the determination of the mean crystallite size and the changes in the mean crystallite size with relation to the diffraction planes 002 and 310. Likewise, the intensity of peaks in the diffractograms corresponding to the same diffraction planes
was correlated with the number of crystallographic planes or of unit cells present in the crystallites.
Bovine Serum Albumin Adsorption on Hydroxyapatite and Biphasic Calcium Phosphate and the Correlation with Zeta Potentials and Wettability
Authors: Zhu Xiang Dong , Fan Hong Song , Zhao Chao Yong , Ikoma Toshiyuki , Tanaka M. , Chen Ji Yong , Zhang Xing Dong
Published: March 2009

Studying on the interaction between proteins and calcium phosphate implants is one of the basic subjects in biomaterials science and engineering. In this work, zeta potentials and contact angles of hydroxyapatite (HA) and biphasic calcium phosphate (BCP) ceramics were measured, and the adsorption behaviors of bovine serum albumin (BSA) on the surfaces were investigated. The
adsorption isotherms of BSA on both ceramics follow the Langmuir type, however, BCP shows higher BSA adsorption ability. The differences of contact angles and zeta potentials in HA and BCP are the key factors to determine their ability to bind BSA molecules.
Effect of Protein Addition on the Setting Behaviour of a Calcium Phosphate Cement
Authors: Chauhan S. , Hofmann M.P. , Shelton R.M.
Published: March 2009

This study investigated the influence of the addition of various proteins to the liquid
phase (albumin, fibrinogen and foetal bovine serum (FBS)) on the mechanical strength and setting time of a brushite forming calcium phosphate cement. Additions of 1wt% protein to the liquid phase led to a deterioration in compressive strength of the set cement by up to 50%. The setting time was not affected by adding albumin and FBS but was increased by 50% with admixtures containing
fibrinogen. The conversion of the reactants, β-tricalcium phosphate and monocalcium phosphate, to brushite was found to be unaffected by addition of up to 10wt% proteins.
Comparative Investigation of Various Adding Methods on Synthesis of Calcium Phosphate Containing Chinese Medicine
Authors: Huang C. , Qu Shao Xing , Feng Bo , Shen R. , Hong Z.M. , Li M.H. , Liu Y.R. , Li Xiao Hong , Weng Jie
Published: March 2009

The purpose of this paper was to investigate the effect of various Chinese medicine
adding methods on their contents in calcium phosphate (CaP) and the crystal structure of the CaP comparatively. In the present study, CaP was synthesized by the wet chemistry method, in which starting reagent grades calcium nitrate and diammonium phosphate were used as the molar ratio Ca/P=1.5. Chinese medicine parenteral solution, Salvia Miltirrhiza Bunge (SMB), was added into
the Ca2+ and PO43- reactive solutions before, during or after synthesis process. CaP was synthesized without adding SMB as the control. UV-VIS spectrophotometer was used to measure the supernatant absorbency. Zeta potential was used to characterize the various CaP slurries.
Thermogravimetry, X-ray diffraction and transmission electron microscope were used to characterize the various powders, respectively. The presented results showed that adding SMB during the reaction can obtain the maximal medicine content among the four different adding methods. There was a slight effect on the crystal structure of CaP by adding SMB.
Statistical Evolution of Microvoids in Particle-Filled Polymers under Plate Impact
Authors: Chen Jian Kang , Huang Zhu Ping , Bai Shu Lin
Published: March 2009

Statistical evolution of microvoids in a particle-filled polymer under plate impact is
theoretically studied. Based on the constitutive equations of the material recently obtained by the authors, the velocity of the propagation of one-dimensional strain wave caused by the plate impact is analyzed, and the evolution of the microdamage is calculated. It is shown that the microvoid evolution is influenced by several factors, such as particle size-dispersity, average radius of particles, and the adhesive energy of the interface. The numerical results show that there is a
sensitive crest of the impact velocity for microvoid evolution. If the impact velocity reaches the critical value corresponding to the peak value of the crest, the microvoids accumulation will increase rapidly, and it may lead to the dynamic failure of the material.
A Fracture Mechanics Based Approach to the Assessment of Seismic Resisting Steel Structures
Authors: Hyland Clark , Ferguson W. George
Published: March 2009

A method for assessing likelihood of brittle fracture in cyclically loaded steel assemblies subjected to inelastic strains is proposed. The method proposed is based upon relationships between monotonic and cyclic endurance of steel specimens proposed by Kuwamura and Takagi, and analysis of crack tip opening displacement (CTOD), Charpy V-Notch (CVN) and tensile results
of pre-strained, fatigue pre-cracked and side-grooved specimens of constructional steel. The proposed method allows the influence of displacement ductility classification (as used in seismic design of structures), notch geometry, and cyclic strain amplitude history on crack initiation to be incorporated into a single design analysis approach. Small scale CTOD testing of steel materials
with various levels of pre-strain may be used to identify stress intensity and crack tip displacement at crack initiation for use in the analysis. The integration of a fracture mechanics based approach to analysing stress intensity in conjunction with assembly plastic deformation characteristics derived from finite element modeling offers the promise of an improved approach to steel assembly design
for cyclic plastic endurance and should result in more reliable structures and reduced need for large scale testing. This has particular relevance to the structural design of seismic resisting steelwork assemblies which are expected to develop dependable ductile behaviour under high strain variable amplitude cyclic actions.
Model Prediction of Thermodynamics Activity in Multicomponent Liquid Alloy
Authors: Fan Tong Xiang , Yang Guang Jun , Chen Jian Qi , Zhang Di
Published: March 2009

This work presents a thermodynamic model to theoretically predict the component
activity in multicomponent liquid alloy based on the Wilson equation and an extended Miedema model. Using only the physical parameters of pure metals, the component activities can be theoretically calculated and the calculation results agree well with the measured data. The model should enable very useful predictions to be made for activities in multi-component liquid alloys, especially for the trend of the activity changes with increasing alloy content.
The Effect of Tungsten Addition on the Thermal Stability and Microstructure in the Electroless Ni-P-W Composite Coating
Authors: Tien Shih Kang , Wu Fan Bean , Duh Jenq Gong
Published: March 2009

Ni-P-W composite deposit on the mild steel substrate was derived by the electroless process. The composition of the eletroless coating was Ni-10.7wt.%P-8.7wt%W analyzed by electron probe microanalysis (EPMA). The coating was annealed at various temperatures from 350oC to 600oC for 4h and the structure at different heat-treated temperature was studied by X-ray diffraction, and transmission electron microscope (TEM). The crystallization behavior was evaluated by the differential scanning calorimeter analysis with continuously heating from room temperature to 550oC at different heating rates. The hardness at all depths of the coating on the substrate could be acquired by the nanoindentation. From the DSC analysis, the onset temperature and crystallization temperature were 397.7oC and 405.5oC, respectively, at the heating rate of 10oC/min. The activation energy of the Ni-P-W coating was 307 kJ/mol analyzed by Kissinger, and Augis and Bennett methods with different heating rates. The Ni-P-W coating showed an amorphous structure in the as-deposited state and exhibited a relatively low hardness of approximately 6.8 GPa. As temperature was raised to 380oC, the hardness was slightly increased to 8.7 GPa due to the partial precipitation of Ni and Ni3P in the amorphous matrix. On heating to 500oC for 4 h, the hardness reached the maximum value of 12.3 GPa with a grain size of 33.1 nm and followed by gradual degradation above 500oC.
Fabrication and Application of Diamond-Coated Bearing Support Implements
Authors: Sun Fang Hong , Wang Y. , Zhang Zhi Ming , Chen Ming
Published: March 2009

The bearing support implement is the key component in the precision process of bearings.
Diamond films are deposited on Co-cemented carbide bearing support implements using the
acetone and hydrogen as the gas source by the bias–enhanced hot filament chemical vapor
deposition (HFCVD) technique. Diamond-coated bearing support implements are fabricated and
used in the precision grinding of bearings. The research results show that the appropriate
pretreatment methods and CVD process can effectively control the morphology, chemical quality,
surface roughness, and adhesion of diamond films. As compared with the cemented carbide bearing
support implements, the diamond-coated bearing support implements have obviously better wear
resistant properties and working performance. It is of great significance for improvement of the
bearing processing quality and raising of the bearing processing level.
Visualized Characterization of Slurry during CMP Based on LIF
Authors: Yuan Ju Long , Lou Fei Yan , Zhou Zhao Zhong , Wang Zhi Wei , Lv Bing Hai
Published: March 2009

Chemical mechanical polishing has emerged recently as an indispensable processing
technique in large scale integration. In chemical and mechanical polishing process, chemical and
mechanical principle is the vital factor in the removal process. Little is known about what is
occurring beneath a wafer during Chemical Mechanical Polishing (CMP) processes. The paper
provides a LIF technology to visualize the fluid flow between the wafer and pad. In this paper, the
experiment setup is built. And then, the images of fluorescence intensity excited by LIF have been
obtained from CCD. Finally, the relationships between pH, temperature, laser power, film thickness
and fluorescence intensity excited by LIF (Laser induced Fluorescence) are studied.
The Analysis and Calculation of Shock Track during Laser Shock Forming
Authors: Yin Su Min , Jin C. , Zhang Yong Kang , Zhou Jian Zhong , Yang Ji Chang
Published: March 2009

In terms of the principle and characteristics, this paper proposes a new method to
implement laser shock forming for large region based on the STL model. The method allows the
build-up of laser shocking track to be accomplished automatically and therefore resolves the
problem of continuous machining in course of the laser shock.
Effect of TiN Addition on the Low Temperature Degradation of Ceramic Tool Materials 3Y-TZP
Authors: Sun Jing , Huang Chuan Zhen , Wang Jun
Published: March 2009

Ceramic tool materials, 3Y-TZP added by TiN particles, were fabricated through
hot-pressing techniques. The effects of TiN on their low-temperature degradation at 220# in air
were investigated. It is shown that TiN can improve the stability of t-ZrO2 and inhibit the
transformation from tetragonal to monoclinic phase, and that the content of TiN affects the stability
of tetragonal phase and the propagation of tetragonal-to-monoclinic transformation into the
specimen interiors. It is suggested that the grain-boundary phase prevents the nucleation of
transformation, and that the high elastic modulus of TiN can prevent the propagation of phase
transformation by resisting the volume expansion of transformation. When the content of TiN is
20wt%, the ceramic material shows better low temperature degradation resistance.
Research on Energy Saving EDM Pulsed Power Supply with Cyclically Superimposed Chopper Circuit
Authors: Di Shi Chun , Wei Dong Bo , Chi Guan Xin , Wang Zhen Long , Jiang J.T.
Published: March 2009

This paper presents an energy saving electrical discharge machining (EDM) pulsed power
supply, the principle of which is introduced. This pulsed power supply possesses no current-limiting
resistors used in conventional EDM pulsed power supplies and no energy storage inductors applied in
most other energy saving pulsed power supplies. Direct current from DC power supply is chopped to
form many branches of paralleling spike pulse currents and the current branches are then combined
into the desired pulse current for EDM machining through cyclic superimposition. The calculation
method of energy loss is then analyzed. The short-circuit and contrastive machining experiments
proved that the new pulsed power supply was capable of performing stable machining with higher
machining efficiency and less main-machining-circuit energy loss than those of conventional EDM
pulsed power supplies.
Research on Influence of Crystal KDP Anisotropy on Critical Condition of Brittle-Ductile Transition in Ultra-Precision Cutting
Authors: Chen Ming Jun , Liang Ying Chun , Wang Jing He , Dong Shen
Published: March 2009

In order to machine high accuracy Potassium Dihydrogen Phosphate (KDP) crystal part,
the indentation experiments are carried out with various loads and various orientation angles. The
experimental results show that the critical condition of brittle-ductile transition of KDP has strong
anisotropy. Therefore, the influence factors on the surface quality of crystal KDP was discussed, it
is shown that influences of the tool's geometry parameter, feed rate and Nominal depth of cut etc on
the surface quality of KDP are main. Afterwards the cutting experimental study on crystal KDP
material is carried out. The experimental results show that the super-smooth surface quality only
can be obtained while KDP is ultra-precision machined in ductile mode.
FEM Simulations on the Milling Dynamics of the Thin-Walled Structure Components
Authors: Wu K. , He Ning
Published: March 2009

The existent studies on milling dynamics of the thin-walled structure components are reviewed first, then a kind of FEM simplified model analyzing the milling dynamics of the thin-walled structure components is proposed. Based on the proposed model, some simulations have been done under different cutting parameters and different machining conditions. At last, the simulation results are analyzed and discussed.
Effects of the Substrate on the Determination of SEBS Thin Film Mechanical Properties by Nanoindentation
Authors: Cao Yong Zhi , Liang Ying Chun , Dong Shen , Sun T. , Wang Bo
Published: March 2009

In order to investigate nanoindentation data of polymer film-substrate systems and to learn more about the mechanical properties of polymer film-substrate systems, SEBS (styreneethylene/ butylene-styrene) triblock copolymer thin film on different substrate systems have been tested with a systematic variation in penetration depth and substrate characteristics. Nanoindentation experiments were performed using a Hysitron TriboIndenter with a Berkvoich tip. The resulting data were analyzed in terms of load-displacement curves and various comparative parameters, such as hardness and Young’s modulus. The results obtained by the Oliver and Pharr method show how the composite hardness and Young’s modulus are different for different substrates and different penetration depth.
FEA and Precision Machining on Ceramic Plunger Couple
Authors: Tian Xin Li , Tang Xiu Jian , Yu Ai Bing , Bi X.P.
Published: March 2009

Ceramic plunger couple are appreciated by engine designer thanks to its high
performances such as anticorrosion and wearproof, however which are restricted due to
machining difficulty. This article will discuss the feasibility of replacing metal material with
silicon nitride ceramics in plunger coupler manufacturing through analysis on change law of
stress and displacement of 12150L diesel engine plunger coupler at rated condition, design and
develop special clamp for intractable spiral line and oil-out trough, and with satisfactory
machining effect.
Effect of α-Alumina as a Seed in Alumina/Silicon Carbide Composites
Authors: Choi Seong Min , Leela-adisorn Uraiwan , Honda Sawao , Hashimoto Shinobu , Awaji Hideo
Published: March 2009

Intra-type structure of ceramic matrix composites (CMCs) can improve the mechanical
properties of ceramic materials. In this work, we used γ-alumina as a matrix including nano-pore for
fabricating alumina/silicon carbide composites using pressure-less sintering and pulse electric current
sintering (PECS) techniques. We added α-alumina as a seed in order to improve densification of this
commercially available γ-alumina. The mixture was sintered from 1250 to 1450 by pressure-less
sintering and PECS techniques. Densification of the specimen sintered by pressure-less sintering is
very difficult and bulk density of the specimen sintered at 1450 showed lower than 3.0 g/cc. In the
case of the PECS technique, the density was improved to 3.8 g/cc in seed added specimen sintered at
1450. Maximum Vickers hardness and maximum fracture strength were obtained 17 GPa and 500
MPa for the seed added specimens sintered at 1450, respectively.
Rapid Fabrication of C/C-SiC Composites
Authors: Wang Ji Ping , Jin Zhi Hao , Qiao Guan Jun
Published: March 2009

C/C-SiC composites, namely carbon fiber reinforced silicon carbide and pyrocarbon
matrices, were fabricated in two steps in this study. Firstly, C/C composites were prepared by a rapid
economical densification process of chemical liquid-vaporized infiltration. PAN based felt and
2-Dimensional carbon fibers were chosen as preform, respectively. A liquid hydrocarbon, kerosene,
was used as a precursor. The C/C composites were processed in a temperature range of 900-1100°C
for 150 minutes. Subsequently, C/C-SiC composites were fabricated from the C/C composites and
silicon powder by reactive melt infiltration method. Densities, open porosities of the C/C and the
C/C-SiC composites were investigated. Structural properties of the C/C-SiC composites were studied
by optical microscopy. X-ray diffraction was used to identify the element and the crystal phase of the
composites. It was shown that the density of C/C composite reached to 1.72 g/cm3 based on the 2D
carbon fibers by CLVI method. Microstructure observation of the C/C composite revealed that the
pyrocarbon is layer concentric around the fibers. It was found that during the RMI processing β-SiC
was formed through the reaction only between liquid silicon and pyrocarbon, while carbon fiber was
not damaged. Free silicon remains in the C/C-SiC composites because of insufficient reaction with
the pyrocarbon.
From Niihara's Equation to Peculiar Nanoindentation Deformation of Ceramics and Semiconductors
Authors: Nowak Roman , Hirvonen Ari T. , Sekino Tohru
Published: March 2009

The present paper is based on the contribution by Niihara and his co-workers devoted to indentation testing of ceramic materials, while it provides new observations of peculiarities registered during nanoindentation of sapphire, GaAs and InGaNAs deposited by MBE-technique. Exploiting previous studies of the spherical indentation in sapphire, the present authors recognized different causes that result in the apparently similar pop-in phenomenon for sapphire and GaAs-based semiconductors. The finite element modeling of the quasi-plastic nanoindentation of the ( 1 1 20) plane of sapphire with the elastically deformable tip confirmed that the deformation of sapphire is governed by twinning which causes pop-in phenomenon, as suggested earlier by Niihara et al. The singularities registered for GaAs-based crystals are associated with dislocation movement within {111} slip bands, which is in contrast to the case of sapphire.
Prediction of Fracture Toughness in Fibrous Si3 N4 Monolithic Ceramics
Authors: Guo Hai , Yoon Dae Hyun , Shin Dong Woo
Published: March 2009

A fracture toughness model of fibrous monolithic ceramics revealed that the major
factor that contributed to the fracture toughness in ceramics was the actual energy absorbed by
crack propagation rather than the total work of fracture. The load-displacement curve and the
crack propagation path were predicted using the derived model mirror image with that of
experimental data.
Wet Jet Milling of Ceramics Powder
Authors: Omura Naoki , Hotta Yuji , Kinemuchi Yoshiaki , Kume Shoichi , Watari Koji
Published: March 2009

Wet jet milling is a new technology for the pulverization of powders, in which streams of
slurry, higher than 100m/s, collide in the channel made of diamond. The effect of processing
parameters was investigated in the system of BN/SiO2 mixed powders. The particle size after
milling was evaluated by the measurement of BET surface area. The BET surface area of BN
increased with increase in the number of milling, in the mixture ratio of SiO2/BN, in the particle
size of SiO2 and in the processing pressure, whereas no significant change in the size of SiO2
particle was found. The surface area of BN increased by about 2.1 times by wet jet milling for only
about 20 minutes (5 times).
Durability of Ceramic Filter for Hot Gas Cleaning
Authors: Shin Min Chul , Cha Jin Sun , Lee Jun Han , Lee See Hee , Lee Hee Soo
Published: March 2009

A porous filter was manufactured using cordierite powder by an extrusion method. The filter had an apparent porosity of 58% and a compressive strength of 10 MPa. Pulse cleaning process affected the durability of the filter. We investigated the effect of operating conditions of a hot gas cleaning system using ceramic filter, thermal shock and pressure shock on durability. When pulse cleaning was repeated periodically, the baseline differential pressure was relatively higher. On the other hand, when we repeated pulse cleaning per specific maximum differential pressure we could improve the durability of the filter. In our test conditions, thermal shock is the most important factor decreasing the durability of the filter. Pressure shock didn’t deteriorate the durability of the filter. However thermal shock caused the formation of cracks at the filter surface. This will lead to an increasing of the baseline differential pressure by depth filtration of dust and decrease the durability of the filter.
Effect of Additives on Dielectric Loss of AlN Ceramics
Authors: Kume Shoichi , Yasuoka Masaki , Omura Naoki , Watari Koji
Published: March 2009

The effects of sintering additives on dielectric loss tangent of AlN ceramics were explored.
Different amounts of Y2O3 and TiO2 were respectively added as sintering additives to AlN powders
and pressureless sintering was performed in a nitrogen flow atmosphere at 1850 °C or 1900 °C for 2
hours. The resulted AlN ceramics became denser when TiO2 addition was more than 0.5 mol%, and a
dense sinter with a relative density of 0.987 could be obtained. Tan δ decreased when TiO2 content
was more than 0.5 mol% and a tan δ value of as low as 1.0 x 10-3 could be attained.
Effect of Alumina Additions on Mechanical and Electrical Properties of 8mol% Yttria-Stabilized Zirconia Prepared by Spark Plasma Sintering
Authors: Kim Jae Kwang , Kim Kyung Hun , Choa Yong Ho , Yoon Jong Won , Shim Kwang Bo
Published: March 2009

Dense 8mol% yttria-stabilized zirconia (8YSZ) consisting of submicrometer-sized grains
was prepared using spark plasma sintering (SPS) along with Al2O3 additives. The starting powder
with average particle size of 50nm was densified to 98% of the relative density with short sintering
time (5min) at 1200 while preserving a submicrometer grain size. The fracture toughness and
bending strength showed maximum values of 2.54MPam1/2 and 380MPa at 2vol% alumina-added
8YSZ, due mainly to the higher relative density and small grain size. The electrical conductivity of
2vol% alumina-added 8YSZ was 0.0278 S/cm at 700 in airThus, alumina additions in 8YSZ
using the SPS method are an effective process to improve the mechanical strength and electrical
conductivity.
Domain Wall Engineering in Potassium Niobate Single Crystals and Their Piezoelectric Properties
Authors: Yokoh Keisuke , Nam Song Min , Kakemoto Hirofumi , Tsurumi Takaaki , Kumagai Hirohiko , Wada Satoshi
Published: March 2009

For potassium niobate (KNbO3) single crystal, the 31 resonators with the highest piezoelectric constant d31 were designed using transformation of axis. We confirmed that the engineered domain configurations with maximum d31 of –55.1 pC/N was caused by a combination between two polarization with polar directions along [101]c and [-101]c directions. Moreover, if there are larger piezoelectric constants from domain wall region, we can expect the much higher piezoelectric properties. To induce the above domain configuration, a new poling method using patterning electrode was investigated. In this study, the two methods on the basis of temperature-induced phase transition at 207 °C and electric-field-induced phase transition at room temperature were investigated.
Synthesis of a New Photochromic ZrO2 Precursor for Preparation of Functional Thin Films
Authors: Nishizawa Kaori , Fukaya Haruhiko , Miki Takeshi , Suzuki Kazuyuki , Kato Kazumi
Published: March 2009

A new photochromic ZrO2 precursor solution was prepared using zirconium tetra-n-butoxide,
4-(phenylazo)benzoic acid and ethyleneglycol monomethylether. The ZrO2 precursor solution was
irradiated with ultraviolet light (UV) at room temperature. After that, UV-irradiated precursor
solution was irradiated with visible light (Vis) at room temperature. UV-Vis spectra were measured
before irradiation, after UV irradiation and Vis irradiation. Changes of UV-Vis spectra indicated that
the new ZrO2 precursor including 4-(phenylazo)benzoic acid shows photochromism. The
phenomena have synchronized with reversible photoisomerization of 4-(phenylazo)benzoic acid in
the precursor. In addition, the difference of peak position originated from Zr-O CT transition
between before UV irradiation and after UV irradiation increased with increasing the concentration
of 4-(phenylazo)benzoic acid. Furthermore, the optimized structure of the new ZrO2 precursor was
derived by density functional theory (DFT) calculation.
New Method to Adsorb Dye Molecules for Dye Sensitized Solar Cell
Authors: Sakai Kenji , Fujimura Kenji , Yoshikado Shinzo
Published: March 2009

TiO2 thin films for the dye sensitized solar cell have been deposited by the electrophoresis method
using the ultra fine particles of TiO2. To adsorb much dye molecules on the TiO2 film,
electrophoresis method and vacuum impregnation have been tried. The quality of TiO2 thin film and
the amount of the dye molecules adsorbed on the thin film affect the energy conversion efficiency
of the dye sensitized solar cell. The condition to adsorb large amounts of dye molecules on the TiO2
film was discussed. The values of open-circuit voltage and short-circuit current increased using both
vacuum impregnation and electrophoresis method to adsorb dye molecules.
Evolution of Crystallographic Grain Orientation of (K0.5Na0.5)NbO3 Piezoelectric Ceramics
Authors: Takao Hisaaki , Saito Yasuyoshi , Aoki Yoshifumi , Horibuchi Kayo
Published: March 2009

The microstructural development of crystalline-oriented (K0.5Na0.5)NbO3 (described as KNN hereafter)-based piezoelectric ceramics during sintering was investigated. The addition of CuO as a sintering aid was found to be effective for fabricating highly oriented and dense KNN ceramics. KNN specimens with 0.5-1.0 mol% CuO sintered at 1100°C for 1 h have both a relative density and a pseudo-cubic {100} orientation degree of 95% or higher. In the early stages of sintering, KNN is formed in the reaction between complementary reactants NaNbO3 and KNbO3, after which oriented grain growth proceeds at a relative density of more than 90%. In addition, the results of TEM observation showed that textured KNN ceramics have a unique pectinate-like domain structure, in which the domain walls consist of {101} planes.
The Development Telemedicine System for Blood Pressure Monitoring via Ethernet
Authors: Moon Yong K. , Song Yu H. , Kim Jae H. , Lee Sang Sik , Mun Joung H.
Published: March 2009

The objective of this study was to develop an Ethernet-based telemedical blood pressure monitor. Although telemedical applications utilizing a variety of media are currently available, present systems do not provide remote signals with regard to integrated vital information, including blood pressure and pulse rate. In addition, the existing systems are largely embedded-structure, single-access, single-process models. Thus, we developed an Ethernet-based blood pressure monitor which includes a client/server structure, and is a real-time multi-access and multi-process system. The client for the developed system uses the Microsoft Comm Control in Microsoft Visual Basic and ODBC to connect Microsoft Chart Control with DB for a user interface. The server is programmed with the J2SE development platform, in a multi-thread structure. The system is capable of receiving data simultaneously. A TCP/IP socket was used for the Ethernet connection. The JDBC was applied to connect with the database for the saving, searching, and sampling of the data. The data transfer failure rate of the developed system was determined to be less than 0.05%.
A New Signal Processing Technique to Estimate Velocity Dependent Dynamic Friction Coefficient
Authors: Shin Ki Hong
Published: March 2009

In general, dynamic friction coefficient in a dry surface condition is dependent on the relative velocity between two sliding bodies. A conventional method of estimating the velocity dependent dynamic friction coefficient is time consuming and requires a special jig to measure the friction forces. In this paper, a new technique called the state space mapping method is proposed based on the nonlinear dynamics of a 1-DOF friction oscillator. One body is constructed as a single degree of freedom system and another body is formed as a moving base that may be built as a rotating disk or a horizontally oscillating plate. The resulting friction induced vibration system is used to estimate the dynamic friction coefficient. The measured vibration signals are utilized to construct a three dimensional plot of acceleration versus state variables. Then, the velocity dependent dynamic friction coefficient can be estimated from the plot. The natural frequency can also be estimated from the plot, which can be used to verify the quality of the results.
Design of a Time-Frequency Distribution for Vibration Monitoring under Corrosions in the Pipe
Authors: Park Gi Young , Lee C.K. , Kim Jung Taek , Kwon K.C. , Lee Sang J.
Published: March 2009

To monitor the wear and degradation on a pipe by corrosion during a plant operation, the
vibration signals were measured by an accelerometer and analyzed by several analysis techniques.
From the conventional methods, it was difficult to identify the wear and degradation on the pipe. And
hence, the time-frequency distribution (TFD) and the adaptive cone-kernel distribution (ACKD)
devised for reducing the interfering cross-terms are applied to the acquired data. They can provide the
distinguishing peak patterns between the normal and corrosion signals.
Measurement of Carboxyl Group Separated from a Thin Film Copolymerized by Low-Temperature Plasma at Atmospheric Pressure of C2H2 and CO2
Authors: Sohn Hong Lae , Cho Young Tae , Lee Bong Ju
Published: March 2009

We developed a device that makes possible the normal generation of low-temperature plasma under atmospheric pressure. For plasma generation, a radio frequency of rf (13.56 MHz) was used, for plasma gas, helium (He), and for material gases, acetylene (C2H2) and toluene (C6H5CH3) were used. As a result of measuring Fourier transform infrared (FT-IR) after adding the CO2 gas to the generated plasma, the absorption of C=O (carboxyl group) was observed around 1715 cm-1. When the flow rates of the added CO2 increased, the absorption peak increased at the same time, and we knew that this originated from the CO2 molecules.
Tribological Performance of Two Oilless Sintered-Metal Bearings for the Geared Motor in a Refrigerator
Authors: Oh Se Doo , Lee Young Ze
Published: March 2009

The tribological performances of two types of oilless sintered-metal bearings with
varying loads were investigated. One is the Cu-based bearing and the other is Fe-based bearing. The
frictional forces of the bearings were measured using the bearing tester. By measuring the change of
weight before and after sliding tests, the oil losses of the bearings were surveyed. Also, PV curves,
which could be used to predict the life of the oilless bearing, were plotted. By observing the
roundness, the cylindericity and the images of scanning electron microscopy of bearings before and
after sliding tests, the tribological characteristics of the bearings were evaluated. It was found that
Fe-based bearing show lower friction, more oil loss, less wear and longer life than Cu-based bearing.
Evaluation of the Ride Comfort for High Speed Trains in Korea
Authors: Kim Young Guk , Kim Seog Won , Park Chan Kyoung , Moon Kyoung Ho , Park Tae Won
Published: March 2009

Evaluation of the ride comfort for railway vehicles can be divided into two classes; the
long-term evaluation of ride comfort and the momentary evaluation of ride comfort. In the present
paper, the ride comfort of railway vehicles are investigated for high speed trains in Korea. The
long-term ride comfort has been analyzed by a statistical method and the momentary ride comfort has
been analyzed by using the longitudinal acceleration, the jerk and the stationary lateral acceleration.
Nonlinear Structural Dynamic Analyses of Micro Cantilever Beams Actuated by Electrostatic Force
Authors: Yoo Hong Hee , Song Simon , Jung Kang Sik , Kim Kwan Yong
Published: March 2009

Nonlinear modeling method for the structural dynamic analysis of a micro cantilever beam
actuated by electrostatic force is presented in this study. Static deflection is first obtained by solving
nonlinear static equilibrium equation and the modal and the stability characteristics are calculated at
the static equilibrium position. It is found that the amplitude and the frequency of the applied
electrostatic voltage influence the stability of the structure significantly.
Finite Element Analysis of an Induced Current Potential Drop Method for the Defect Detection of Railway Axles
Authors: Goo Byeong Choon , Lim C.H. , Kwon Seok Jin
Published: March 2009

NDT(Non-Destructive Testing) is useful for the defect detection of rolling stock because
it can be used to detect defects in many invisible parts. In rolling stock one of the components
vulnerable to damage is the axle. Fatigue cracks are initiated in press-fitted parts such as the wheel
and brake disk seats of the axle. Those parts suffer from fretting fatigue damage. A precise and
reliable NDT technique is necessary to detect cracks in the axle. But conventional induced current
potential drop methods (ICPD) have some difficulties to detect such cracks in press-fitted parts of
axles. In this study, we have introduced an induced current focusing potential drop method (ICFPD),
a new concept that can be applied to the press-fitted parts of the axle. And we have measured
electromagnetic properties of the wheelsets and performed finite element analysis for wheelsets
with defects. Results suggest that the method is very powerful and effective to detect defects.
Application of Ultrasonic Test on Creep-Fatigue Life Evaluation
Authors: Kim Bum Joon , Lim Byeong Soo , Song Sung Jin , Kim Young H.
Published: March 2009

This work investigates the relationship between the creep-fatigue life and ultrasonic test of
creep-fatigue damage. Under the creep-fatigue interaction, the main cause of life reduction is the
initiation and growth of microvoid with increasing hold time. The number/size of microvoid/cavity,
the fraction of cavity area varied with the hold time. Therefore, the life evaluation using the microvoid
with the variation of hold time is very informative for safety of components in power plants. In this
study, using the heat resisting alloy, P122 steel for USC (ultra super critical) power plant, the
creep-fatigue tests with various hold times and their ultrasonic inspection were carried out for the
purpose of evaluation for creep-fatigue life. The results obtained by Rayleigh surface wave of
backscattered ultrasound were compared and analyzed with the experimental parameters. The good
agreement between the experimental life and the predicted life was obtained.
Ball SAW Sensors for Safety and Reliability of Fuel Cell Technologies
Authors: Yamanaka Kazushi
Published: March 2009

Detection of hydrogen gas is a crucial task for establishing safety and reliability of fuel cells, a key technology for the environment and our society. However, hydrogen is difficult to detect and various hydrogen sensors have many drawbacks. Here we report a novel hydrogen gas sensor, the ball surface acoustic wave (SAW) sensor, using Pd or PdNi sensitive film. The ball SAW sensor is based on a novel phenomenon, diffraction-free propagation of collimated beam along an equator of sphere. The resultant ultra-multiple roundtrips of SAW makes it possible to achieve highest sensitivity among SAW sensors. Moreover, it enables to use a very thin sensitive film, and consequently the shortest response time (2s) was realized. In terms of the sensing range, it has the widest range of 10 ppm to 100 % among any hydrogen sensors including FET or resistivity sensors. The ball SAW sensor can be applied not only to hydrogen but also to any gasses and possibly to liquids.
Characterization of Material Degradation in Epoxy Film Based on Scanning Acoustic Microscopy (SAM)
Authors: Kim Noh Yu , Nah Hwan Seon , Lee Sang Soon
Published: March 2009

In order to evaluate the degradation of the epoxy coating in nuclear power plants, acoustic
wave velocities of epoxy films are measured using defocused scanning acoustic microscopy
system(SAM). Unlike metals, the surface of the epoxy coating on the concrete liner is so thin and
wavy that the conventional ultrasonic techniques for acoustic velocity of epoxy coating are hard to
apply. Acoustic velocities of bulk waves are determined from V(z,t) curves of mode-converted waves
generated in the film by SAM. Epoxy films are fabricated and degraded under various accelerated
aging conditions, and both of longitudinal and shear wave velocities of the epoxy film are measured.
Approximately 10% of reduction in acoustic wave velocity is observed from experimental results
when the aging is developed fully in epoxy films. It is also found that longitudinal wave is more
sensitive to deterioration of epoxy coating than transverse wave.
Nondestructive Detection of Crack and Delamination of Ceramics Coating on SUS304 Stainless Steel Using ESPI Method
Authors: Wang Rong Guang , Kido Mitsuo , Shinhara Yoshiko
Published: March 2009

An electronic speckle pattern interferometry (ESPI) method was applied to nondestructive detection of cracks and delaminations of ceramics coating (Al2O3/NiCr) on SUS304 stainless steel. A drop of surface strain on the coating was found when cracks in the coating or delaminations from the coating/substrate interface occurred.
Burst Pressure Estimation of Steam Generator Tubes Based on Fracture Mechanics Analyses
Authors: Chang Yoon Suk , Kim Young Jin , Hwang Seong Sik , Kim Joung Soo
Published: March 2009

During the past couple of decades, several limit load solutions have been proposed to
resolve steam generator (SG) tube integrity issue. However, for estimation of specific load carrying
capacity under different conditions, these solutions have to be modified by using lots of experimental
data. The objective of this paper is to introduce a new burst pressure estimation scheme based on
fracture mechanics analyses for SG tubes with a crack. In this context, closed-form equations were
derived to get relevant parameters from three dimensional elastic-plastic finite element analyses and,
then, a series of structural integrity analyses were carried out using the predicted J-integrals from the
equations. Finally, in comparison with the experimental data as well as corresponding estimation
results from conventional limit load solutions, it was proven that the proposed estimation scheme can
be used as an efficient tool for integrity evaluation of cracked SG tubes.