bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Stability and Mechanical Properties of Plasma Sprayed Al2O3/ZrO2 Nano-Composite Coating
Authors: Sodeoka Satoshi , Suzuki Masato , Inoue Takahiro
Published: March 2009

Alumina/zirconia nano-composite coating was fabricated by plasma spraying using
agglomerated feedstock from fine powders of about 100 nm. The coating was consisted of fine
γ-alumina and zirconia crystals with size of several nano meter and some amorphous boundary layers.
The amorphous phase was crystallized and disappeared after heat treatment at 930°C. However, the
crystallite size was kept under 50 nm even after 1500°C-100hr heating, so the alumina-zirconia
nano-composite showed good thermal stability against the grain growth.
Design and Characterization of Porosity Gradient for the Laminated Alumina Tubes
Authors: Chen Chun Hong , Ishiguro Satoshi , Honda Sawao , Awaji Hideo
Published: March 2009

Based on the FGM concept, laminated alumina tube with a tailored porosity gradient along the radial direction has been successfully fabricated by the lamination method in the centrifugal molding technique. Experiments were performed with colloidally processed alumina powder and pore-former agent. The powder mixture was made into slurry in water media and the tubes were cast using a stainless steel mold. The porosity profile was designed with the presence of PMMA particles as pore-former agent and the nature of porosity was investigated by microstructure observations. The bimodal pore structure of the tubes was constructed from large spherical pores about 10 μm formed by burning-out the pore-former agent and small sub-micron pores caused by the lower sintering temperature. The fracture behavior of porous tubes with tailored porosity gradient was investigated using the O-ring compression testing. The failure behavior was divided into two types depending on the pore-former agent. The air permeability and fracture behavior were independent of the lamination process. The influence of the porosity gradient on the fracture strength was investigated and the results showed there was a reduction in fracture strength with increase in the laminate number, and the minimum strength was found in continuous graded tubes.
The Self-Regenerative "Intelligent" Catalyst for Automotive Emissions Control
Authors: Tan Isao , Taniguchi Masashi , Tanaka Hirohisa , Uenishi Mari , Kajita N. , Nishihata Y. , Mizuki Jun'ichiro , Niihara Koichi
Published: March 2009

Co-free LaFePdO3 perovskite catalyst with the self-regenerative function of Pd was
developed. This technology was named the “intelligent catalyst”. Suppression capacity for Pd
particle growth and catalytic activity of the Co-free perovskite LaFePdO3 were compared with those
of LaFeCoPdO3. It was confirmed that Pd particles on LaFePdO3 maintained a nano-particle size by
the results of XAFS analysis and TEM observation after aging in engine exhaust gas at 900 °C, and
LaFePdO3 demonstrated an excellent light-off performance. Further, the design configuration for
LaFePdO3 in the washcoat was investigated to maximize the self-regenerative function under
practical conditions.
Removal of Heavy Metal Ions from Aqueous Pb-EDTA and Cu-EDTA Solutions Using Nanosized ZnO Powders by Solution-Combustion Method
Authors: Lee Ju Hyeon , Seo Jung Uk , Chung Yun Joong , Lee Jae Chun , Park Sung
Published: March 2009

ZnO nanopowder was prepared by a novel “solution-combustion method (SCM)” and it
was used as a semiconductor photocatalyst to evaluate its photoreduction properties. Aqueous
Pb-EDTA and Cu-EDTA solutions of heavy metal ions (Pb and Cu) were used for the photocatalysis
reaction under UV illumination. The result was then compared with other semiconductor
photocatalyst powder such as TiO2 powder (P25; Degussa) and TiO2 powder prepared by
homogeneous precipitation process at low temperature (HPPLT). In the removal of Pb++ ions, the
ZnO nanopowder showed 2.6 fold higher removal rate than P25 TiO2 powder and 1.8 fold higher than
HPPLT TiO2. Also the ZnO nanopowder showed the highest removal rate of the Cu++ ions from the
solution among the different photocatalyst powders compared. The superior photoreduction ability of
the ZnO nanopowder appears to be due to its excellent UV absorption characteristics. This was
confirmed by the photoluminescence (PL) measurement.
Effect of Sintering Temperature on Structure, Piezoelectric and Ferroelectric Properties of (Na0.5Bi0.5)0.90Ba0.10TiO3 Ceramic
Authors: Xu Qing , Chen X.L. , Wu S.J. , Chen Wen , Wang Hao , Kim B.H. , Lee J.H.
Published: March 2009

Structures, ferroelectric and piezoelectric properties of (Na0.5Bi0.5)0.90Ba0.10TiO3 ceramic
sintered at different temperatures were investigated. The results confirm an important role of
sintering temperature on the structure and electrical properties of the ceramic. It was found that the
increase of sintering temperature in the range of 1110-1160 promoted the development of
crystal structure and microstructural densification, leading to an improvement in ferroelectric
properties, poling process and piezoelectric properties. Further increase of the sintering temperature
above 1160 resulted in a slight deformation of ceramic specimens. With respect to sintering
behavior and piezoelectric properties, a relatively narrow sintering temperature range near 1150
was ascertained to be preferred for the ceramic.
Syntheses of Bulky Y-Zeolite by Hydrothermal Hot-Pressing (HHP) Technique
Authors: Takezoe S. , Hosoi Kazuyuki , Tajika Masahiko , Yamasaki Yuki , Nakahira Atsushi
Published: March 2009

Synthesis of bulky Y-zeolite was attempted by a hydrothermal hot-pressing (HHP) method.
These bulky products synthesized under hydrothermal conditions were identified as Y-zeolite single
phase. Especially, bulky Y-zeolite having translucency, high density and large surface area was
obtained by HHP treatment at 423K for 2h with 17wt% of 5M-NaOH solution. This solidified zeolite
like single-crystal was considered to be made by dissolution and precipitation mechanism.
High-density bulky zeolites can be expected as novel molecular sieves and catalysts with high
activity.
Influence of Oxygen on the Damping Properties of Nb-Zr Alloys
Authors: Florêncio Odila , Silva Paulo Sergio , Stefanini T.F. , Botta Filho Walter José
Published: March 2009

Nb-1 wt% Zr polycrystalline and single crystalline samples were submitted to annealing,
at pressure of 2.5 x 10-8 Torr and subsequently annealed in an oxygen atmosphere for three hours, in
a temperature of 1170 K in oxygen at partial pressure of 5 x 10-5 Torr. Internal friction
measurements as a function of temperature were performed between 300 K and 650 K, using a
torsion pendulum inverted Kê-type operating in a frequency oscillation in the hertz bandwidth.
Three internal friction peaks, which were assigned as Nb-O, Zr-O and Nb-N peaks were observed in
oxidized single crystal sample and the relaxation parameters of the three peaks were obtained.
Different Damping Dependences on Volume Fractions of Thermal and Deformation-Induced ε Martensites in an Fe-Mn Alloy
Authors: Jun Joong Hwan , Lee Young Kook , Kim Jeong Min , Kim Ki Tae , Jung Woon Jae
Published: March 2009

We reports the damping properties of an Fe-23%Mn alloy with various amounts of thermal or deformation-induced ε martensite. By controlling cooling temperatures and cold rolling degrees, the volume fractions of thermal and deformation-induced ε martensites are changed from 33 to 50% and from 33 to 75%, respectively. The damping capacity of the Fe-23%Mn alloy increases with an increase in thermal ε martensite content, whereas the damping capacity associated with deformation-induced ε martensite shows a peak value at 57% of ε martensite. Transmission electron micrographs on deformed samples reveal that the decay of damping over 57% of deformation-induced ε martensite is caused by an introduction of perfect dislocations, which play a role in suppressing the movement of damping sources. For the same amount of ε martensite, deformation-induced ε martensite exhibits higher level of damping capacity than thermal ε martensite. This may well be owing to relatively greater length of γ/ε interfaces in response to higher number density of ε martensite plates.
Fe-Cr-Mn-(Co) High Damping Stainless Alloy (HIDAS)
Authors: Yamagami K. , Kogo Y. , Morizumi T. , Isono H. , Kosaka T. , Miyahara K. , Igata N.
Published: March 2009

Based on the recent requirements, high strength, high damping stainless alloy HIDAS was developed. The chemical compositions are Fe-12%Cr-22%Mn and Fe-12%Cr-22%Mn-2%Co. After solution annealing, microstructure consisting of austenite fcc , martensite hcp and bcc ’. When cold work was given, and increased. Damping capacity increased with the increase of phase. The mechanism of high damping capacity would come from the hysteretic motion of Shockley partial dislocations which are lying at interphase interface of /. This alloy has also high strength. This is due to fine structure of /. Because of these properties, HIDAS can be applied to machinery industries.
Near-Infrared Light Emission from of Er-Doped ZnO Thin Film in Micropits Processed on Si Substrate
Authors: Tanaka Shigeru , Ishikawa Yukari , Ohashi Naoki , Niitsuma Junichi , Sekiguchi Takashi , Shibata Noriyoshi
Published: March 2009

We have obtained Er-doped ZnO thin film in a micropattern of reverse trapezoids processed on Si
substrate by sputtering and ultrafine polishing techniques. Near-infrared light emission was detected
successfully from the thin film filling a single micropit with 10 μm square. Transmission electron
microscopy (TEM) observation showed epitaxial growth of ZnO crystals along the curvature of the
micropit.
Preparation and Dielectric Properties of 3D Barium Titanate Colloidal Sphere Array
Authors: Yazawa Aki , Hoshina Takuya , Kakemoto Hirofumi , Tsurumi Takaaki , Wada Satoshi
Published: March 2009

Barium titanate (BaTiO3) colloidal sphere array was prepared by meniscus method using capillary force
between particles from slurry. To pack particles closely, well-dispersed slurry was obtained using electric
double layer. From SEM observation, it was confirmed that the colloidal sphere array had point contact or
plane contact. Dielectric permittivity of prepared colloidal sphere array was measured at 1 MHz by
impedance analyzer. An obtained sample with point contact showed about the same dielectric permittivity as
that of simulation by finite element method (FEM) using closed packed model. However, colloidal sphere
arrays with plane contact showed lower permittivity than a sample with point contact. From XRD
measurement of these samples, it was suggested that the low permittivity was originated from lattice strain or
smallness of particle size.
Micropattern of Colloidal Crystal by Using Electrophoretic Deposition Process with Three-Electrode System
Authors: Hamagami Jun Ichi , Hasegawa Kazuhiro , Kanamura Kiyoshi
Published: March 2009

A novel micropatterning process for a particle assembly has been performed by using an electrophoretic deposition (EPD) method with a local electric field in a colloidal suspension generated by a three-electrode system. Monodisperse silica colloidal spheres with a diameter of 300 nm were used to fabricate micropattern of colloidal crystal. An interdigitated gold-microarray electrode with a 10 μm of width and a gold plate electrode were used as the working and the counter electrodes, respectively. After optimization of the EPD processing parameters, a micropattern was constructed from silica colloidal spheres. It had a relatively close-packed structure formed onto the interdigitated microarray electrode. This micropattern showed a characteristic optical reflectance peak due to Bragg’s law.
Doping Effect on Crystal Structure of Fast Oxide Ion Conductor LaGaO3-Based Perovskite Compounds
Authors: Kajitani Masahiro , Matsuda Motohide , Hoshikawa Akinori , Kamiyama Takashi , Izumi Fujio , Miyake Michihiro
Published: March 2009

Doping effects of Sr and/or Mg on the crystal structures of LaGaO3 perovskites were investigated.
The doping with Mg into Ga-site in LaGaO3 led to structural change from the orthorhombic
primitive lattice (Pbnm) to the orthorhombic body-centered lattice (Ibmm) at room temperature.
The orthorhombic cell (Ibmm) of LaGa0.9Mg0.1O2.95 changed to the monoclinic (I2/a) by doping
with Sr into La site. Neutron powder diffraction analyses revealed that these compounds had
GaO6 octahedral tilt. The GaO6 octahedral tilt angles were reduced with doping with Sr and/or
Mg.
Piezoelectric Properties and Depolarization Temperatures of (Bi1/2Na1/2)TiO3-(Bi1/2K1/2)TiO3-BaTiO3 Lead-Free Piezoelectric Ceramics
Authors: Hiruma Yuji , Yoshii Kazushige , Aoyagi Rintaro , Nagata Hajime , Takenaka Tadashi
Published: March 2009

The piezoelectric properties of a solid solution based on the three components of bismuth
sodium titanate, (Bi1/2Na1/2)TiO3 (BNT), bismuth potassium titanate, (Bi1/2K1/2)TiO3 (BKT), and
barium titanate, BaTiO3 (BT), that is, x(Bi1/2Na1/2)TiO3-y(Bi1/2K1/2)TiO3-zBaTiO3 [BNBKy:z(x);
x+y+z=1] are investigated. Fine piezoelectric properties in lead-free piezoelectric ceramics were
obtained near the MPB composition, and the highest electromechanical coupling factors, k33 and kp,
and piezoelectric constant, d33, were 0.58 and 0.36 for BNBK2:1(0.89) and 181 pC/N for
BNBK2:1(0.88), respectively. In this study, we also measured the depolarization temperature, Td,
from the temperature dependence of dielectric and piezoelectric properties.
Growth and Electric Properties of Al-Substituted Langasite-Type La3Ta0.5Ga5.5O14 Crystals at High Temperature
Authors: Takeda Hiroaki , Tanaka Satoshi , Shimizu Hiroyuki , Nishida Takashi , Shiosaki Tadashi
Published: March 2009

We report an effective substitution of aluminum for gallium in langasite-type La3Ta0.5Ga5.5O14
(LTG) crystals for use in a pressure sensor at high temperature. Al-substituted LTG
(La3Ta0.5Ga5.5-xAlxO14; LTGAx) single crystals up to the solubility limit of x=0.5 have been grown
by the conventional Czochralski technique. The electric properties of the LTGAx crystals were
investigated and compared with those of LTG. By Al substitution, the piezoelectric constant d11 and
the electromechanical coupling factors (k12) became slightly larger. The LTGAx crystals showed a
lower temperature dependence of d11 and a higher electric resistivity ρ than those of the LTG
crystals.
Large-Scale Synthesis and Electrochemical Properties of LiAlXMn2-XO4 Powders by Internal Combustion Type Spray Pyrolysis Apparatus Using Gas Burner
Authors: Mukoyama Izumi , Myoujin Kenichi , Ogihara Takashi , Uede Masao , Ozawa Hironori , Ozawa Kazunori
Published: March 2009

Spherical LiAlxMn2-xO4 fine powders were continuously produced by Internal Combustion Type
Spray Pyrolysis Apparatus Using Gas Burner from metal nitrate precursor solutions. XRD showed
that LiAlxMn2-xO4 powders were well crystallized in a spinel structure with the Fd3m space group.
As-prepared powders have a spherical particle shape with a diameter of 2.3 μm. As-prepared
samples were calcined at 800
for 10 h in air. The charge/discharge capacity of LiAlxMn2-xO4 was
over 100 mAh/g. A powder production capacity speed of 1 kg/h was attained by this system.
Electrical Properties of Grain-Oriented SrBi2Nb2-xVxO9 Ceramics
Authors: Inai Shinya , Hiruma Yuji , Aoyagi Rintaro , Nagata Hajime , Takenaka Tadashi
Published: March 2009

Vanadium-substituted strontium bismuth niobate, SrBi2Nb2-xVxO9 (SBNVx), ceramics were
synthesized by a low-temperature ceramic fabrication process; their electric properties were
characterized, and grain orientation effects on their electric properties were also investigated using a
hot-forging (HF) method. Resonance characteristics of the (33) and (15) modes of grain-oriented
SBNV0.1 (HF) showed relatively high electromechanical coupling factors of k33=0.272 and
k15=0.151 as well as piezoelectric constants of d33=31.7 pC/N and d15=24.8 pC/N. The temperature
dependences of the resonance frequency (TC-f) of the (33) and (15) modes of the SBNV0.1(HF)
ceramics were -16.5 ppm/°C and –25.5 ppm/°C, respectively.
Crystallization Behavior of KNbO3 Series Precursors Synthesized by CSD Process
Authors: Tanaka Kiyotaka , Kakimoto Kenichi , Ohsato Hitoshi
Published: March 2009

The development of lead-free piezoelectric materials has been required from the viewpoint of environmental preservation. We focused the lead-free KNbO3-based systems, and used a chemical solution deposition (CSD) process to obtain their precursor. (Na1-xKx)NbO3 precursor solutions were prepared from metal alkoxides and solvents such as absolute ethanol and 2-methoxyethanol. Crystallization behavior of the precursor gels obtained from the above solutions was investigated by the thermogravimetry differential thermal analysis (TG-DTA) measurement.
Ultrasonic Nondestructive Measurement Systems – Models and Measurements
Authors: Lopez-Sanchez Ana , Schmerr Lester W.
Published: March 2009

The electroacoustic measurement model is an explicit model of an entire ultrasonic
measurement system, including the pulser/receiver, cabling, and transducers. A summary is given of
the measurement procedures needed for characterizing all the system elements contained in this
measurement model, including a description of a new pulse-echo method for obtaining the
sensitivity and impedance of an ultrasonic transducer. It is demonstrated that these models and
measurement procedures can be combined to accurately simulate the measured voltage of a pulseecho
immersion system.
Influence of α-Adrenoceptor Mediated Vasoconstriction on Spontaneously Hypertensive Rats after Exercise Training
Authors: Seo Young Hwan , Im Kwang Hee
Published: March 2009

This study aims to examine the effects of aerobic exercises for 8 weeks on vascular
contraction with α-adrenaline acceptor in SHR (Spontaneously Hypertensive Rats). The rats of 8
weeks with hypertension (SHR) having the weight of 155165g were aerobic-exercised with using
treadmill for 5 days a week through 8 weeks (20m/min). After 8 weeks, chest artery is extracted,
suspended into organ bath and changes of isotonia tension are recorded on vital records. The piece
of extracted chest artery showed density depending contraction by norepinephrine and its sensitivity
to Emax and norepinephrine was significantly reduced after aerobic exercise for 8 weeks.
Contraction reaction was accelerated in both groups after eliminating endothelium cell, but when LNNA
was input in the state with endothelium cell, contraction reaction by norepinephrine was
increased in exercise group and its aspect was similar to the contraction by norepinephrine in the
state eliminating endothelium cell. Relaxation by acetylcholine was significantly increased in
exercise group, but there was no difference in relaxation by sodium nitroprusside. In conclusion,
vascular endothelium cell isolates niotric oxide and reduces contraction reaction of blood vessel
with α exercise group, but there was no difference in relaxation by sodium nitroprusside.
Non-Invasive Analysis of the Micro-Structural and Biomechanical Properties of Trabecular Bone in Human Femoral Head
Authors: Won Ye Yeon , Baek Myong Hyun , Cui Wen Quan , Kim Kwang Kyun
Published: March 2009

This study investigates micro-structural and mechanical properties of trabecular bone in
human femoral head with and without osteoporosis using a micro-CT and a finite element model. 15
cored trabecular bone specimens with 20 of diameter were obtained from femoral heads with
osteoporosis resected for total hip arthroplasty, and 5 specimens were removed from femoral head of
cadavers, which has no history of musculoskeletal diseases. A high-resolution micro-CT system was
used to scan each specimen to obtain histomorphometry indexes. Based on the micro-images, a
FE-model was created to determine mechanical property indexes. While the non-osteoporosis group
had increases the trabecular thickness, the bone volume, the bone volume fraction, the degree of
anisotropy and the trabecular number compared with those of osteoporotic group, the
non-osteoporotic group showed decreases in trabecular separation and structure model index.
Regarding the mechanical property indexes, the reaction force and the Young's modulus were lower
in the osteoporotic group than in non-osteoporotic group. Our data shows salient deteriorations in
trabecular micro-structural and mechanical properties in human femoral head with osteoporosis.
Nondestructive Cucumber Quality Evaluation System Using Machine Vision
Authors: Kang Suk Won , Lee Kang Jin , Lee Ho Young
Published: March 2009

This study was aimed at developing a new quality evaluation system for classifying the
cucumber based on its length and curvature, and removing the taper and dumbbell shaped cucumbers
using the thickness changes. Especially machine vision technique was used in carrying out field
application. The cucumber image was obtained from a frame grabber, and the image was improved by
minimizing the nonuniform illumination and image blurring due to line movement. From the obtained
image, background was separated from the original image, and cucumber length and curvature was
calculated after thinning and post-processing operation. After thinning operation, cucumber region
was sliced and the thickness was calculated. From the thickness calculation, cucumber can be
classified as straight, cudgel and dumbbell shape. The classification rate for bowing was close to
100%. The overall average recognition rate for good, dumbbell and cudgel cucumber fruits was
90.7%
Application of Sensors to Assess Soil Conditions in a Korean Paddy Field
Authors: Chung Sun Ok , Chong Byong Hak , Kang Suk Won , Kim Gi Young
Published: March 2009

Precision agriculture, also called as site-specific crop (or field) management, is a recent
trend in crop production that uses field information collected at different within-field locations to
optimize amount, timing, and location of agricultural inputs according to the site-specific
requirements. Recent development of soil property sensors has facilitated sensor-based data
collection for SSCM in many countries around the world. In this study, commercial soil strength,
electrical conductivity, and water content and temperature sensors were applied to a Korean rice
(Oriza Sativa L) field and spatial and non-spatial statistical techniques were used to assess soil
conditions and the variability, and investigate optimum sampling intensity. Results of the study would
be useful for establishment of data collection schemes and better application of soil property sensors
to Korean paddy fields for successful precision agriculture.
Analysis of Characteristics of In-Line Magnetic Resonance Sensor
Authors: Kim Seong Min , McCarthy Michael J.
Published: March 2009

This study was performed to show the feasibility of nuclear magnetic resonance (NMR)
techniques for quality evaluation of various agricultural and food products. A real-time in-line NMR
quality evaluation sensor was designed, constructed and tested. The device consists of an NMR
spectrometer coupled to a conveyor system and a data acquisition system. The conveyor was run at
speeds ranging from 0 to 300 mm/s. An NMR signal can be detected when a sample is within ±50
mm of the NMR coil center. The response of NMR sensor was tested using several fruits. The
results showed a feasibility of an NMR sensor for evaluating internal quality of various fruits.
High Speed Decoding of Entropy Codes in H.264/AVC Based on a Symbol Prediction
Authors: Kim Chung Hyo , Kong Tae Sik , Lee Young Jun , Kim Hee Dong , Ju Young Ho
Published: March 2009

H.264/AVC is adopted as a next generation moving picture compression standard. Context-based Adaptive Binary Arithmetic Coding (CABAC) is the major entropy coding algorithm employed in H.264/AVC. Although the performance gain of H.264/AVC is mostly resulted from CABAC, it is difficult to implement a high-throughput decoder due to its decoding complexity. Although CABAC excludes a multiplication, the algorithm is basically sequential and needs large computations to compute some important variables, which are range, offset and context variables. Therefore, it is difficult to achieve fast decoding performance. In this paper, a prediction scheme is proposed to decode maximally two bits at a time and thus to reduce overall decoding time. A CABAC decoder based on the proposed prediction scheme reduces total cycles by 24% compared to conventional decoders.
Wavelet Based Multi-Bit Fingerprinting Against Geometric Distortions
Authors: Kim Won Gyum , Seo Yong Seok , Jung Hye Won , Lee Seon Hwa , Oh Won Geun
Published: March 2009

This paper presents a new image fingerprinting scheme which embeds a multi-bits
fingerprinting code and is robust against the geometric attack such as rotation, scaling and translation.
We construct a 64 bits fingerprinting code and embed into wavelet subband of 512x512 images
repeatedly. In order to restore an image from geometric distortion a noise reduction filter is performed
and a rectilinear tiling pattern is used as a template. Results of experimental studies show that our
method is robust against geometric distortions and JPEG compression.
Optical Properties for ZnSe Epilayer Obtained From Photoluminescience Measurement
Authors: Lee Sang Youl , Hong Kwang Joon
Published: March 2009

The ZnSe epilayers were grown on the GaAs substrate by hot wall epitaxy. After the
ZnSe epilayers treated in the vacuum-, Zn-, and Se-atmosphere, respectively. The defects of the
epilayer were investigated by means of the low-temperature photoluminescence measurement.
The dominant peaks at 2.7988 eV and 2.7937 eV obtained from the PL spectrum of the as-grown
ZnSe epilayer were found to be consistent with the upper and the lower polariton peak of the
exciton, I2 (Do, X), bounded to the neutral donor associated with the Se-vacancy. This donorimpurity
binding energy was calculated to be 25.3 meV. The exciton peak, I1
d, at 2.7812 eV was
confirmed to be bound to the neutral acceptor corresponded with the Zn-vacancy.
Nondestructive Evaluation of Corrosion Progression on Titanium and Its Alloy Surface by Wetting Method
Authors: Wang Rong Guang , Kido Mitsuo , Mukai Koji
Published: March 2009

The corrosion behavior of pure titanium and Ti-6Al-4V alloy in NaF solutions and the
wettability of pure water on the specimens after corrosion were investigated. The relation between the
change of surface chemistry and roughness of specimens after corrosion and the wettability of pure
water droplets on such surfaces were discussed.
Fracture Characteristic of Aged DLC Films Using Nano-indentation and Micro-indentation
Authors: Baek Seung , Koo Jae Mean , Seok Chang Sung
Published: March 2009

In this study, we performed fracture tests on thermally aged DLC thin films by using
micro-indentation and nano-indentation and investigated the deformation and fracture
characteristics of these films. The aged high hydrogen films have better characteristics such as thermal
and mechanical stability than low hydrogen films.
Determination of the Mechanism Based Deposition Processes of Thin Film in OLED
Authors: Lee Kwang Ki , Lee Kwang Soon , Kim Tae Won
Published: March 2009

Physical vapor deposition technique has been employed to develop a thin film of OLED, and atomic force microscopy was used to investigate the boundary characteristics such as uniformity of emitting layer, roughness, and surface morphology. In order to determine the deposition characteristic which associated with the materials failure in OLED, finite element simulation, together with alternative analytical modeling has been carried out by means of island growth mechanism analysis. The boundary growth of thin film can be determined from the velocity of island boundary using simple rate equations. The results obtained are compared with experimental observation. Generally good agreement has been achieved.
Nondestructive and Non-Contact Characterization Technique for Metal Thin Films Using a Near-Field Microwave Microprobe
Authors: Yoo Hyun Jun , Kim Jong Chel , Babajayan Arsen , Kim Song Hui , Lee Kie Jin
Published: March 2009

We observed the surface resistance of metal thin films by a nondestructive characterization
method using a near-field scanning microwave microprobe (NSMM). The NSMM system was coupled
to a dielectric resonator with a distance regulation system. To demonstrate the ability of local
microwave characterization, the surface resistance dependence of the metallic thin films has been
mapped nondestructively.
Measurement of Alloying Degree of Galvannealed Steels by X-Ray Diffraction
Authors: Park Hyoung Kuk , Hong Jea Hwa , Lee Chong Soo
Published: March 2009

Galvannealed steels are produced by reheating of Zinc-coated steels, in which the iron and the zinc are interdiffused to form Zn-Fe intermatallic compound. In recent years, application of galvannealed steel has increased due to its excellent corrosion resistance, good weldability and paintability. Galvannealed production requires strict control of processing conditions to obtain an optimal alloying degree in the coatings. The analysis of the alloying degree is very important since they are closely related to the corrosion and mechanical properties. This study is measurement of alloying degree of the galvannealed steel by using the XRD. Partial least squares (PLS) model is a powerful multivariate tool that has been successfully applied to the quantitative analysis of data in XRD. The alloying degree was determined by using PLS regression to a concentration accuracy of 0.2%. The XRD analysis and proposed PLS model can be successfully used to determine the alloying degree of industrially produced galvannealed steel.
Ultrasonic Characterization of Residual Stress in Shot Peened AI 7075 Alloy Using Acoustic Signature
Authors: Kim C.S. , Cho Dong Su , Park Ik Keun
Published: March 2009

We attempted to estimate the residual stress which evolved during the shot peening of Al
7075 alloy using leaky surface acoustic wave (LSAW). Shot peening was conducted to produce a
variation in the compressive residual stress with the depth from the surface at a shot velocity of 30m/s.
The LSAW velocity was measured using a scanning acoustic microscopy (SAM). The Vickers
hardness profile obtained inwards from the surface showed significant work hardening of the near
surface layer with a thickness of about 0.3mm. The variation in the LSAW velocity through the shot
peened surface layer was in good agreement with the distribution of the residual stress measured by
X-ray diffraction.
Evaluation of Surface and Internal Defects of Railway Wheel using Induced Current Focusing Potential Drop
Authors: Kwon Seok Jin , Lee Dong Hyung , Seo Jung Won , Lee Chan Woo
Published: March 2009

In the present paper, the induced current focusing potential drop (ICFPD) technique is
applied to the detection of surface and internal defects for railway wheels. To detect the defects for
railway wheels, the sensors for ICFPD are optimized and the tests are carried out with respect to 4
surface defects and 3 internal defects each other. The results show that the surface defect of 0.5 mm
and internal crack of 1.0 mm apart from surface of wheel tread could be detected by using this method.
The ICFPD method is useful to detect the defect that initiated in the tread of railway wheels.
Reliability Assessment Approach Using Failure Mode Analysis in Machining Center
Authors: Kim Bong Suk , Lee Soo Hun , Kim Jong Soo , Song Jun Yeob
Published: March 2009

The importance of evaluation and establishment during product development process, for
the reliability and safety of mechanical system and parts, is getting increased in the field of
mechanical and electronic industry. The object of this paper is to suggest the reliability assessment
method for machine tools using failure mode analysis and to introduce two web-based analysis
programs which save all data related to failure rate, failure mode, and failure component. In order to
evaluate the reliability of machine tools, this paper takes three steps: the use of previous database, the
failure rate estimation using failure history data, and the failure mode analysis using performance test.
Determination of the Hydrogen Concentration in Zr-2.5Nb Alloy by a Resonant Ultrasound Spectroscopy
Authors: Cheong Yong Moo , Kim Young Suk
Published: March 2009

Zirconium alloys are used for many applications in nuclear components, such as the pressure tube material in a pressurized heavy water reactor, nuclear fuel cladding, etc. One of the problems during the operation of a nuclear reactor is the degradation of the zirconium alloys, which is due to an increase of the hydrogen content in the zirconium alloy. Therefore a non-destructive determination of the hydrogen concentration in zirconium alloy is one of the important issues that need to be addressed. The resonant ultrasound spectroscopy (RUS) technique is evaluated for a characterization of the hydrogen concentration in Zr-2.5Nb alloy. Referring to the terminal solid solubility for dissolution (TSSD) of Zr-2.5Nb alloy, the plot of the mechanical damping coefficient (Q-1) versus the temperature or the deviation of the resonant frequency for the temperature (df/dT) versus the temperature was correlated for the hydrogen concentration in Zr-2.5Nb alloy. It was found that the temperature at an abrupt change of the slope can be correlated with the hydrogen concentration of the Zr-2.5Nb alloy.
Characteristics of Crack Detection on Plates Using Strain Mode Shapes; Sensor Grids and Geometry
Authors: Kim Beom Seok , Yoo Seung Hyun , Lee Sang Jo , Baik Sung Kook
Published: March 2009

The existence of a crack in a structure produces changes in modal parameters of it such
as natural frequencies, damping, displacement and strain mode shapes. This paper is focused on
characterization of crack detection methods using strain mode shapes. To characterize crack
detection methods, we changed sensing grids from corner grid to cross grid and geometry of the
specimens from rectangular to triangular plate. Rest of conditions was fixed. For crack detection
criteria, COMAC, ECOMAC, ADSM and new method have been used and the results are compared
with each other. The COMAC, ECOMAC and ADSM showed limited capacity of crack detection
on plates but the new method gave good results in 90% of all cases.
Dynamic Stability Characteristics of Axially Accelerated Beams
Authors: Yoo Hong Hee , Eun Sung Jin
Published: March 2009

Dynamic stability of axially accelerated beams is investigated in this paper. The equations
of motion of a fixed-free beam undergoing axially accelerated motion are derived. Unstable regions
due to the acceleration are obtained by using the Floquet’s theory. Stability diagrams are presented to
illustrate the influence of the acceleration characteristics. Large unstable regions of flutter type
instability exist around the first, twice the first, and twice the second bending natural frequencies.
Divergence type instability also occurs when the acceleration exceeds a certain value. The validity of
the stability diagram is confirmed by direct numerical integration of the equations of motion.
Performance of Electro-Active Papers Made with Cellulose and Multi-Walled Carbon Nanotubes
Authors: Kim Jae Hwan , Yun Sung Ryul , Song Chun Suk
Published: March 2009

Cellulose-based Electro-Active Paper (EAPap) has been studied as an attractive electroactive
polymer material for artificial muscles due to its low cost, availability, lightweight, large
displacement output, low actuation voltage and low power consumption. However, the force output
of EAPap is small since paper is so flexible that the bending stiffness is low. In this paper, the
cellulose based EAPap material is enhanced by using carbon nanotubes with cellulose paper.
Coating of multi-walled carbon nanotubes mixed with polyaniline on EAPap as well as MWNT
dispersion in the paper are tried to enhance the force output of the EAPap. The coating process of
MWNT/PANI on the EAPap and the dispersion of MWNT in the cellulose paper are explained. The
performance of the hybrid EAPap actuators is evaluated in terms of tip displacement, blocking force
and electrical power consumption. The power output and the actuator efficiency are improved.
Nondestructive SANS Study of Reactor Pressure Vessel Steel after Irradiation
Authors: Han Young Soo , Shin Eun Joo , Seong Baek Seok , Lee Chang Hee , Park Duck Gun
Published: March 2009

The irradiation induced defects of irradiated reactor pressure vessel(RPV) steel were investigated by a small angle neutron scattering. The degradation of the mechanical properties of RPV steels during an irradiation in a nuclear power plant is closely related to the irradiation induced defects. The size of these defects is known to be a few nanometers, and the small angle neutron scattering technique is regarded as the best non destructive technique to characterize the nano sized inhomogeneities in bulk samples. The RPV steel was irradiated in the HANARO reactor in KAERI. The small angle neutron scattering experiments were performed at SANS instrument in the HANARO reactor. Both unirradiated and irradiated RPV steels were measured and the SANS data of both steels were compared. The nano sized irradiation induced defects were quantitatively analyzed by SANS. The type of defects was also analyzed based on the SANS results, and the effect of the chemical composition of the RPV steel on the irradiation induced defects was discussed.
Interfacial Reaction of Cu-Tie Coating-Polyimide Flexible Copper Clad Laminates
Authors: Lee Jea Won , Lee In Seon , Kang Tae Won , Kim Dong Won , Kim Sang Ho
Published: March 2009

Adhesion of flexible copper clad laminates (FCCL) on two different types of polyimide
(PI), sputtering raw polyimide (SRPI) and casting raw polyimide (CRPI), were studied. Chromium
(Cr), strongly reacts with dangling O bonds, was used as tie-coating layer in order to improve low
adhesion between copper (Cu) and polyimide (PI). Polyimide surfaces were pretreated with gas
plasma that was generated with a mixture of argon and oxygen before sputtering process. Adhesion
measurement was performed on these samples according to IPC specification. The results show that
the peel strength of the FCCL on SRPI was higher than on CRPI. This is considered to be due to the
formation of Cu-Cr-O solid solution at the metal- PI interface.
Surface Monitoring Technique for Fatigue Effect of Shape Memory Alloys(SMAs)
Authors: Chang Kug Kwan , Rhee In Kyu , Roh Young Sook
Published: March 2009

There have been very few research results available for high cycle fatigue properties of
SMAs. In many of the devices designed to exploit the effect of fatigue loadings, the specimen is
subjected to only several thousand thermal or loading cycles. Therefore, the stability of the alloy
under applied loading with high cycle fatigue becomes an important issue. Moreover, there has not
been any fatigue testing in compression for SMAs. The behavior of SMAs under tension and
compression may be different, which is very important for many special applications of SMAs. The
present study focus on the high cycle fatigue of SMAs under compression. A new surface
monitoring technique for micro-deformation and micro-strain analysis, called IIMT, is introduced.
IIMT is used for monitoring the performance of SMAs under high cycle stress loading in
compression. The stress-strain curves and shape memory strain output at various loading cycles
were obtained, which provide valuable information for design and applications of SMAs.
Cohesive Zone Parameters for the Interface between NiTi Shape Memory Alloy and CFRP
Authors: Yang Seung Yong
Published: March 2009

To explore the structural strength of CFRP shape memory alloy composites, it is necessary
to evaluate the interface bonding strength. Jang and Kishi experimentally investigated the adhesive
strength between NiTi fibers and CFRP composite [1]. In this paper, the interface de-decohesion
behavior was simulated by three-dimensional cohesive zone method. The values of related numerical
parameters were chosen to fit the experimental result.
On-Line NDE and Structural Health Monitoring for Advanced Reactors
Authors: Nakagawa N. , Inanc F. , Frishman A. , Thompson R. Bruce , Junker W.R. , Ruddy F.H. , Dulloo A.R. , Beatty J.M. , Arlia N.G.
Published: March 2009

This paper considers the use of on-line structural health monitoring in advanced nuclear
power systems such as IRIS. The motivation for the on-line health monitoring is to prevent routine
maintenance from interrupting long-term continuous reactor operation. However, the outcome of the
on-line monitoring implementation has a broader impact, and amounts to a paradigm shift in
maintenance strategy from outage-based maintenance to continuous real-time monitoring of
operational and structural integrity. Indeed, on-line health monitoring data will provide a foundation
for diagnostics and prognostics (i.e., predictive) capabilities that will detect component degradation
prior to failure, thus allowing for proactive rather than reactive maintenance strategies. Specifically,
this paper briefly reports on our studies on (1) on-line monitoring strategy and its benefits, (2)
candidate reactor components where on-line monitoring provides maximum benefits, (3) applicable
on-line NDE sensor methodologies and conceptual sensor designs, and (4) model-based sensor
performance estimations.
Evaluation of the J Integral of a Surface Crack by the Three-dimensional Local Hybrid Method
Authors: Machida Kenji , Mizukami Gaku , Oyama Hirohisa
Published: March 2009

To evaluate the 3-D stress field inside a specimen from displacement data on the free
surface obtained from the 2-D intelligent hybrid method, we developed the 3-D local hybrid method
based on inverse problem analysis. In a previous study, when a uniform load was applied to a
structure with a surface crack, it was demonstrated that the stress field was analyzed with high
accuracy. In this study, the 3-D local hybrid method was applied to a structure with a surface crack
subjected to bending load. However, a suitable solution was not able to be obtained on a bending
problem. Therefore, another method was applied. The relative error between the J integral value of
the whole model and the local model was compared, and accuracy was investigated. First, the
variation of accuracy with width and thickness was examined. If thickness is increased, the relative
error decreases as found in the uniform load case. Moreover, as width increases, the relative error
decreases. However, even if width and thickness become large, accuracy does not necessarily
become better. Therefore, the relative error was compared and a suitable hybrid size was examined.
Assessment of Structural Integrity for a Concrete Runway by Seismic Techniques
Authors: Joh Sung Ho , Kang Tae Ho , Kwon Soo Ahn
Published: March 2009

Concrete runways are subject to material deterioration or structural problems, which lead to surface cracks and scaling of a concrete pavement. In this study, seismic techniques including the SASW method, the impact-echo method and the impulse-response method were integrated into a systematic nondestructive approach, which is designed for the assessment of structural integrity of concrete runway pavements. Numerical simulation of the employed seismic methods was performed to verify the validity. For feasibility, the integrated approach was applied to a concrete runway which has surface cracks at pavement segments not subject to airplane loading. The approach verified that the surface cracks were attributed to reduced subgrade stiffness, which may not be detected by conventional pavement tests. The validity of the integrated approach was also proven in lieu of forensic engineering for concrete runway pavements.
Effect of Confining Pressure on Modeling High Early Strength Concrete under Uniaxial Loading
Authors: Oh Bo Hwan , Rhim Hong C. , Park Hyo Seon
Published: March 2009

Better understanding of concrete behavior is beneficial to the determination of concrete
strength and detection of cracking using nondestructive testing techniques such as ultrasonic and
acoustic emission. For advanced nondestructive evaluation of high early strength concrete under
triaxial compression loading, stress-strain relationship in axial as well as in radial directions needs to
be described in explicit form. This paper presents empirical models developed for high early strength
concrete under active confinement to explore the effect of confining pressure. Empirical model for
axial stress-strain relationship is determined first. Transverse deformation model is automatically
generated from the given axial stress-strain model using plastic strain rate. Parameters used in the
model are identified and their recommended values are provided. Compressive strength of 24 MPa
and 45 MPa concretes are considered along with four different levels of confining pressures.
Analytical Evaluation of Plastic Resistance of Column Base Connection Using Convex Set Theory
Authors: Choi Jae Hyouk , Ohi Kenichi
Published: March 2009

It is important to estimate the structural safety of column base connection by calculating
exact collapse loads. Column bases connection transfer reactions from the structure the foundation. In
this paper, a simple mechanical model to predict their plastic resistance is proposed. An efficient
linear-programming technique, which is called as Compact Procedure, is applied to column base
connection model including multi-spring elements, where a column base is replaced by a set of plastic
axial and bending springs. In Compact Procedure, it is not necessary to know the whole interaction
surface of resistances at a plastic portion. A simple analytical model of column base connection to
calculate its load-carrying capacity considering bi-axial loading effect is presented. In addition,
efficiency of the proposed model is examined by comparing it with the past test results.
A New Eddy Current 3-D Profilometry for a Quantitative Measurement of Geometric Anomaly in Steam Generator Tubes of Nuclear Power Plants
Authors: Lee Deok Hyun , Choi Myung Sik , Hur Do Haeng , Han Jung Ho , Song Myung Ho , Lee Un Chul
Published: March 2009

Most of the corrosive degradations in steam generator tubes of nuclear power plants are
closely related to the residual stress existing in the local region of a geometric change, that is, an
expansion transition, u-bend, ding, dent, bulge, etc. Therefore, accurate information on a geometric
anomaly in a tube is a prerequisite to the activity of a non destructive inspection for a precise and
earlier detection of a defect in order to prevent a failure during an operation, and also for a root cause
analysis of a failure. In this paper, a newly developed eddy current technique of a three-dimensional
profilometry is introduced and the proof for the applicability of the technique to a plant inspection is
provided. The quantitative profile measurement using a new eddy current probe was performed on
steam generator expansion mock-up tubes with various geometric anomalies typically observed in the
operating power plants, and the accuracy of the measured data was compared with those from the
laser profilometry.
DC Potential-Drop Technique for the Evaluation of 3-D Back-Wall Cracks in Steel Structures
Authors: Reaz Ahmed S. , Saka Masumi , Takeo Fumio
Published: March 2009

A direct-current potential-drop NDE technique has been developed for the evaluation of a 3-D back-wall crack in thick-walled structures. The measuring system contains two pairs of probes – one for current supply and the other for the measurement of potential-drop, where the currentsupply and measuring probes are in close proximity to each other. The optimum arrangement of the four-point-probes system is determined from the finite-element simulation of the three-dimensional electric crack problem. The predicted potential-drop across the crack has been verified experimentally using the newly developed measuring sensor. Measured results of semi-elliptical cracks in stainless steel plates establish the practicality as well as reliability of the present potentialdrop method of testing for the evaluation of 3-D back-wall cracks in thick-walled structures.