bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of Wheel Tread for Property Improvement of Railway Wheel
Authors: Kwon Seok Jin , Seo Jung Won , Hur Hyun Mu , Kwon Sung Tae
Published: March 2009

Despite of improvement of wheel material for railway vehicle, the damages of railway
wheel have been occurred in service running. Because of wheel damage with spalling, shelling and
thermal crack, the maintenance cost for the railway wheel has increased. The railway wheel had
standardized but the chemical composition, the mechanical property and the hardness with respect
to railway wheel is merely established. In order to reduce wheel damage, it is necessary to reinforce
the standard of railway wheel. In present study, the fracture mechanics characteristics of railway
wheel such as low cycle fatigue, fracture toughness, impact energy depended on low temperature
and so on have tested. The result shows that the standard of railway wheel has to supplement
fracture toughness and impact energy depended on low temperature etc.
Creep Characteristics and Micro-Defects of Main Steam Pipe Steel at High Temperature
Authors: Jeong C.S. , Kim Bum Joon , Lim Byeong Soo
Published: March 2009

The initiation and growth of micro-defects such as micro cracks and voids usually causes
the failure of long term operated structural components at high temperature. In this study, the creep
characteristics and void nucleation and growth characteristics of P92 steel which is used as main
steam pipe material in power plant were investigated at several temperatures and loading conditions.
The area fraction of void increased with increase of test temperature, stress, and load holding time.
In case of internal defect presence, micro-voids initiated in the early stage of loading period and
resulted in the increased load line displacement and crack growth rate. The microvoids were found
to form along the prior austenite grain boundaries and at the martensite packet boundaries.
Stability Limits of Premixed Methane-Air Microflames for Micropower Generation
Authors: Kwon Oh Chae , Lee K.H. , Ko H.S. , Kim Tae Sung
Published: March 2009

Stability limits of premixed microflames were experimentally and computationally studied
in order to understand the fundamental behavior of the flames when applied for micropower
generation. Single microflames were generated on microtubes with inner diameters of 300-420 μm
for methane-air mixtures at temperatures of 298-400 K and atmospheric pressure. For all the
microflames at normal temperature, the stability limits were observed in a fuel-rich region, which is
different from conventional macroflames exhibiting fuel-lean stability limits. Similar to the
macroflames, however, the stability limits of the microflames show C-shaped curves in a tube exit
Reynolds number (Re) – fuel equivalence ratio diagram, due to insufficient residence times and heat
losses. For elevated temperature that is realistic condition for micropower generation using a
heat-recirculation concept, the stability limits were extended toward the fuel-leaner conditions.
Numerically predicted structure of microflames near the critical point (that is defined as the
fuel-leanest condition among the C-shaped fuel-rich stability limits) showed significant fuel-dilution
immediately near the tube exit due to a low Re effect, explaining why the stability limits of
microflames are observed only in the fuel-rich region. Microcombustors for micropower generation
should be designed to completely consume fuel for better performance.
Fatigue Damage Analysis of Drill Pipes Using FEM and Cox Regression Model
Authors: Farhangdoost Khalil , Siahpoosh Mehran
Published: March 2009

Drill pipe fatigue damage occurs under cyclic loading conditions due to, for instance,
rotation in a dogleg region. This paper presents two approaches to evaluate damage in drillpipes;
First, Finite Element Method is used to evaluate cumulative effects of fatigue damage with respect
to the actual drilling conditions and the fatigue damage curves for smooth and die-marked drill
pipes are obtained. Second, as a case study, the Cox Regression Model, a broadly applicable
method of survival analysis is used to analyze the failure data of the southern oilfields of Iran. The
resultant cumulative survival and hazard functions can reliably predict the time of failure.
Experimental Investigation on Friction and Wear of Coated Vane under the Environments of Lubricants and CO2 as a Refrigerant
Authors: Oh Se Doo , Lee Kyu Sun , Kim Jin Sun , Cho Sung Oug , Lee Young Ze
Published: March 2009

The CO2 was investigated as an alternative refrigerant to replace HFC
(hydrofluorocarbons) refrigerant in air conditioning systems due to the environmental concerns.
Because new compressors with CO2 are going to be operated under the high pressure, the tribology
of sliding surfaces in the compressor becomes very important. To develop new compressor,
especially rotary type, the friction and wear characteristics of sliding surfaces between a vane and a
roller in the rotary compressor were evaluated in this paper. Several hard coatings, such as TiN,
CrN and WC/C, were applied on vane surfaces in order to improve the tribological characteristics,
and their performances were evaluated experimentally. Two types of lubricants were used, namely
POE (polyol ester) oil and PAG (polyalkylene glycol) oil. The vane-on-disk type sliding tests were
performed with an exclusive high pressure wear tester. From the tests, wear volumes of vane
surfaces applied various coatings were compared. Test results showed that WC/C and CrN coatings
showed good tribological properties. Also, the results of the sliding tests showed that using PAG oil
has an advantage over POE oil in CO2 environment.
Influence of Stick-Slip Behavior on Friction and Wear under Fretting Conditions
Authors: Jeong Sung Hoon , Yong Seok Ju , Ahn Tae Shik , Lee Young Ze
Published: March 2009

Friction and wear characteristics between two steel surfaces under fretting condition are
investigated experimentally. The fretting damage caused by low-amplitude oscillatory sliding can be
classified into three regimes of gross-slip, mixed-slip and partial-slip due to stick-slip phenomenon.
One of the most important characteristics of fretting wear is the transition from gross-slip to
mixed-slip. This study was focused on getting the degree of stick-slip out of the friction transition
under fretting condition. Fretting wear is divided into three conditions of gross-slip/mixed-slip/
partial-slip. The criteria for the division are friction and displacement amplitude, wear scar
morphology and dissipated energy. In this test, friction force and displacement were measured for
detecting the transition from mixed-slip to gross-slip and qualitatively predicting the degree of the
wear.
Physical Modeling and Characteristics of a Johnsen-Rahbek Type Electrostatic Chuck
Authors: Choi Jae Seok , Yoo Jeong Hoon , Hong Sang Joon , Kim Tae Hyun , Lee Sung Jin
Published: March 2009

Generally, a Johnsen-Rahbek (J-R) type electrostatic chuck (ESC) generates higher
attractive force than a Coulomb type ESC. Attractive force in a J-R type ESC is caused by the high
electrical resistance that occurs in the contact region between an object plate and a dielectric layer.
This research tries the simple geometrical modeling of the contact surface and simulates the contact
resistance, the attractive force and the response time according to the variation of contact surface
shape. In the latter half of this research, the simulation for a pin-combined chuck is accomplished
using a similar surface modeling and the comparison between the pin chuck and the general flat
chuck is made in aspects of the attractive force and the response time.
A Study on the Cooling Characteristics of TMA Clathrate Compound with Additives
Authors: Kim Chang Oh , Kim Jin Heung , Chung Nak Kyu
Published: March 2009

This study aims to find out cooling characteristics of TMA 25wt%-water clathrate
compound with ethanol such as supercooling, phase change temperature and specific heat. For this
purpose, ethanol is added as per weight concentration and cooling experiment is performed at -6,
-7 and -8, cooling heat source temperature, and it leads the following result. (1) Phase change
temperature is decreased due to freezing point depression phenomenon. Especially, it is minimized
as 5.1 and 5.0, 3.8 according to cooling source temperature in case that 0.5wt% of ethanol is
added. (2) If 0.5wt% of ethanol is added, average supercooling degree is 0.9 and minimum
supercooling is 0.8, 0.7 according to cooling heat source temperature. The restraint effect of
supercooling is shown. (3) Specific heat shows tendency to decrease if ethanol is added. It is
3.013~3.048 kJ/kgK according to cooling heat source temperature if 0.5wt% of ethanol is added.
Phase change temperature higher than that of water and inhibitory effect against supercooling can
be confirmed through experimental study on cooling characteristics of TMA 25wt%-water clathrate
compound by adding additive, ethanol.
Experiments and Characteristic Analysis of a Sealless Pneumatic Cylinder
Authors: Kim Dong Soo , Bae Sang Kyu , Choi Byung Oh
Published: March 2009

This paper shows the performance analysis of a sealless cylinder with a conical type
piston and one of three types of rod bearings. The piston without seal is composed of cylindrical
and conical portions in the axial direction. The 2D Reynolds equation is solved with a finite
difference method for the performance analysis. The relationship between self-centering force and
leakage flow rate are investigated. The sealless cylinder fabricated with the proposed optimum
design values was tested with three different types of rod bearings having four, five and six pockets
respectively. Leakage flow rate tests were conducted to evaluate the performance of the proposed
sealless cylinder.
Image Processing for Optical Methods to Analyze Shape, Deformation, Stress and Strain
Authors: Morimoto Yoshiharu
Published: March 2009

The authors have been developing some novel methods to measure shape, deformation,
stress and strain of structures using optical methods and image processing as follows: (1) Phase
analysis methods using Fourier, wavelet or Gabor transforms, etc., (2) Real-time 2-D strain
measurement using moiré interferometry, (3) Scanning moiré method using thinning-out of
scanning lines and a DMD camera (4) Strain rate distribution measurement by a high-speed video
camera, (5) Real-time integrated phase-shifting method, (6) Shape measurement methods using
multi-reference planes, a linear image sensor, or a frequency modulated grating, and (7) Windowed
phase-shifting digital holographic interferometry (WPSDHI). Theories of these methods and some
applications are introduced. The most accurate result is 88 picometer standard deviation of errors
using the WPSDHI.
A Study of Judder Vibration in Automotive Disk Brakes
Authors: Cho Ho Joon , Cho Chong Du , Kim Myoung Gu , Maeng Ju Wong , Lee Sang Kyo
Published: March 2009

In this experimental paper, the judder vibration of automotive disk brake was analyzed by
the finite element method and compared with experimental results. The relationship between
specific modes of disk and pad, and hot spot was investigated. Characteristics of the judder
vibration were measured by using the chassis-dynamo and hot spots were photographed by highspeed
infrared camera. Vibration modes of the brake disk and pad were measured and an specific
relationship between mode shapes and hot spots was found. Results show that the judder vibration
occurred due to the frequency modulation of the specific mode frequency of disk brake due to the
non-linearity phenomenon. This relationship was examined by the frequency analysis of the judder
vibration.
Modulating the Optical Fiber Sensor of Laser Doppler Anemometry for Measuring the Chicken Blood Velocity
Authors: Chen Yung Chung , Chen Zhao Cheng , Lu Tung Wu , Chen Chien Ming
Published: March 2009

We designed a new module of Laser Doppler Anemometry (LDA) with fiber optical
system, which is mainly comprised of a laser diode, optical fibers and a two dimensional (2D)
photodetector. The fiber optical system involved a laser diode (VCSEL, Copax Inc.) with 850 nm
wavelength, single mode fiber (Prime Optical Fiber Inc.), half coupler and two fiber collimators.
The 2D photodetector made by silicon PIN photodiode is aligned between the two collimators with
39° beams cross angle and all the components were set into a rectangle case, which have coin’s size
and can be accommodated by two same set of these components. We added anticoagulant and
antiseptic into fresh chicken blood and diluted it with normal saline, and then put the diluted blood
into a beaker with a motor in the liquid. The diluted blood was pumped by the motor into an
aqueduct which is connected to glass aqueduct, and back to the beaker to form a circulation system.
In the experiments, we evaluate the relationships among the blood cell velocity and diameter of
glass tube, temperature variation of blood, and concentrations of blood. By analyzing the results of
these experiments, the main factor that affects the precision of velocity measurement is the cross
angle of two injected laser beams and the intensity of scattering light. The module constructed by
optical fiber light can precisely measure the velocity of blood flow at most 5% error.
Development and Evaluation of a Contacting Force Measurement System in a High Temperature and Pressure Water Condition for Fretting Wear Experiments
Authors: Lee Young Ho , Kim Hyung Kyu
Published: March 2009

New system (load cell) for measuring a contacting force in a high temperature and
pressure water condition (i.e. 320, 15 MPa) has been developed. The primary purpose is to apply
it to the experiments of a nuclear fuel fretting wear, which occurs on the contacts between the fuel
rods and the spacer grid spring/dimples due to a flow-induced vibration of the rods. A bi-axial load
cell of a cylindrical shape is specially designed. Strain gages for a special use in a high temperature
condition were attached on to the sensitive region of it to accommodate the bi-axial loading
condition in fretting. The full scale of this load cell is ±50 N in axial force and ±50 N in bending
force, respectively. In order to increase the sensitivity and to compensate for an ambient
temperature effect, the load cell consists of two Wheatstone full bridge arrangements. The
calibration results of the load cell show that the coupling effects of each force were almost
negligible. This paper mainly presents the experimental techniques used during the development of
the new load cell system. The techniques are characterized by a design optimization of a jig of a
cylindrical type, the application of a metallic sealant for a waterproofing, a free welding fabrication
process and a temperature compensation circuit. Details on the development procedure, calibration
method and application results are also given in this paper.
A Piezoelectrically Actuated Biomimetic Walking Robot
Authors: Yumaryanto Abdul A. , An Jae Bum , Xin Li Li
Published: March 2009

In this paper we present the design and prototype of a six-legged walking robot which
uses Lightweight Piezoceramic Composite curved Actuator (LIPCA) as its actuator. LIPCA consists
of multiple layers of glass/epoxy and carbon/epoxy that encapsulate a unimorph piezoelectric
ceramic actuator. It uses lightweight fiber-reinforced plastic layers, and it is a lighter structure and
generates a higher force and a larger displacement than other conventional piezo-composite type
actuators. Like most six-legged walking insects including cockroaches, our robot uses the
alternating tripod gait where the front and rear legs on the same side move together with the middle
leg on the other side for its locomotion. Two LIPCA strips in different phases are used for actuating
each tripod so that only one tripod may touch the ground ensuring static stability while walking. All
the experiments with the prototype show that LIPCA can be used as an alternative actuator for small
and light mobile robots.
Estimation Local Strength of Bow Structure for High Tensile Steel Yacht Based on Optimum Design
Authors: Park Joo Shin , Kim Yun Young , Yao Tetsuya
Published: March 2009

The optimum design for bow structure of high tensile steel yacht belongs to the nonlinear
constrained optimization problem. The determination of scantlings for the bow structure is a very
important matter out of whole structural design process of a yacht. The optimum design results are
produced with the use of Real-coded Micro-Genetic Algorithm including evaluation LR small craft
guideline, so that they can satisfy the allowable stress criterion. In this study, the minimum weight
design of bow structure on the HTS yacht was carried out based on the finite element analysis. An
analysis model is a bow structure of HTS yacht with structural scantling derived from the minimum
weight optimization. The weight of bow structure and the main dimensions of structural members
are chosen as an objective function and design variable, respectively. Optimization results were
compared with a pre-existing design. From the FE analysis results, bow structure with high tensile
steel (AH40) designed by using RμGA has a volume efficiency of 19% than the design of the actual
mild yacht.
Development of a Bi-Axial Acceleration-Detecting Device for a Tube
Authors: Oh Dong Seok , Lee Young Ho , Shin Chang Hwan , Chun Tae Hyun , Kim Hyung Kyu , Lee Kye Bock
Published: March 2009

A new device for measuring an acceleration in a fuel rod has been developed. The
primary purpose is to apply it to the experiments for a nuclear fuel fretting, which is caused by a
fuel rod and grid interaction due to a flow-induced vibration of the rods. A bi-axial accelerationdetecting
device of a cylindrical shape for an insertion into a cladding tube is designed. Two
unimorph piezoelectric accelerometers of small size and for special use in a high temperature
condition were attached to the housing’s inner wall of the mounting device, which were oriented
perpendicularly with each other to accommodate the acceleration signal during a fretting.
Verification is carried out by a displacement and a frequency response analysis. The verification
results of the bi-axial acceleration-detecting device showed a good response for the amplitude and
bi-directional trace. This paper mainly presents the detailed design of the bi-axial accelerationdetecting
device which is developed by using the design optimization of a cylindrical type and
applying it to the lower and upper plugs to sustain the device in the tube wall. The verification is
carried out by a displacement analysis and a frequency response analysis. An elaboration of the
development procedure, calibration method and results are also given in this paper.
A Micro Fluxgate Magnetic Sensor Using New Printed Circuit Board Technology
Authors: Choi Won Youl , Hwang Jun Sik , Choi Sang On
Published: March 2009

We have developed a micro fluxgate magnetic sensor using new printed circuit board
(PCB) technology. The fluxgate sensor consisted of five PCB stack layers including one layer of
magnetic core and four layers of excitation and pick-up coils. The center layer as a magnetic core
was made of micro patterned amorphous magnetic ribbon with an extremely high DC permeability
of ~100,000, and the core had a rectangular ring shape. Four outer layers as an excitation and pickup
coils had a planar solenoid structure. The amorphous magnetic core was easily saturated due to
the high permeability, low coercive field, and closed magnetic path for the excitation field. The chip
size of the fabricated sensing element was 7.3 × 5.7 mm2. Excellent linear response over the range
of –100 μT to +100 μT was obtained with sensitivity of 780 V/T at excitation sine wave of 3 Vp-p
and 360 kHz. A very low power consumption of ~8 mW was measured. This low power, small size,
and high sensitive fluxgate sensor to measure a low magnetic field is very useful for various
applications.
Characterization of Impact Fracture Behavior of Biodegradable PLA/PCL Polymer Blend
Authors: Takayama Tetsuo , Todo Mitsugu , Arakawa Kazuo
Published: March 2009

Attempts have been made to improve the impact resistance of biodegradable
thermoplastic polymer, PLA. A ductile biodegradable polymer, PCL, has been used to improve such
property of PLA by using blending technique. Details of the impact fracture properties and
mechanisms of PLA/PCL blends, however, have not fully been understood yet. Recently, it was also
found that LTI can improve the immiscibility between PLA and PCL. In this study, PLA/PCL and
PLA/PCL/LTI blends were prepared, and their impact fracture toughness values were measuredto
assess the effect of PCL content and LTI addition on the impact resistance. Fracture mechanisms of
the polymer blends were also characterized by scanning electron microscopy.
Impact Energy Measurement of a Hydraulic Breaker
Authors: Park Jong Won , Kim Hyoung Eui
Published: March 2009

A hydraulic breaker for construction machinery generally used for the destroying and
disassembling of buildings, crashing road pavement, breaking rocks at quarry and so on. So the
measurement of the impact energy of a hydraulic breaker is very important thing to prove its
capability to manufacturers and customers. In this study, the test system for measuring the impact
energy of a hydraulic breaker was designed and constructed. The test system was consisted with
hydraulic cylinders for mounting a breaker, impact absorbing base and frames, pressure and flow
sensors, high speed and accurate data acquisition system diesel engine driven hydraulic power
unit. The test process of the developed system was carried by measuring guide for tool energy rating
for hydraulic breakers which was developed by the CIMA (Construction Industry Manufacturers
Association) USA. The developed test system can be applied to measure the impact energy for
various kinds of hydraulic breakers.
Effect of Al18B4O33 Whisker Surface Treatment on Aging Behavior of Al18B4O33 Whisker/ ZK60 Magnesium Alloy Composites
Authors: Wang W.G. , Hasegawa Y. , Choi Yong Bum , Fuyama Nobuyuki , Matsugi Kazuhiro , Yanagisawa Osamu , Sasaki Gen
Published: March 2009

MgAl2O4 layer with several decade nano-meter in thickness was coated uniformly on
Al18B4O33 whisker by vapor-deposition of pure magnesium in vacuum and then heat-treated in
atmosphere in order to prevent to the direct reaction between Al18B4O33 whisker and molten ZK60
(Mg-(4.8-6.2)%Zn-(0.45-0.8)%Zr) alloy in preparing the composites. By the coating, the composite
have no interfacial reaction in whisker and matrix. As the consumption of Zn at the interface was
not observed during preparation of the composites, the composites have good aging behavior, but
showed the shortening of the time to reach the peak hardness. As the cooling speed of the composite
after solution treatment is slow because of low thermal conductivity of the composites, some
precipitation (MgZn2) was observed in the composites. Furthermore, the precipitation grew around
the interface between whisker and matrix preferentially because of thermal stress around the
interface. It seems these phenomena affect to the shortening of the time to reach the peak hardness.
Bending Characteristics of Plate-Type Piezoelectric Composite Actuators According to Applied Electric Fields and Drive Frequencies
Authors: Woo Sung Choong , Goo Nam Seo
Published: March 2009

A performance evaluation of plate-type piezoelectric composite actuators (PCA) having
different lay-up sequences was experimentally carried out at simply supported and fixed-free
boundary conditions. The actuating displacement of the manufactured PCAs was measured using a
non-contact laser displacement measurement system. It was shown that the actuating displacement
with increasing applied electric field at a drive frequency of 1 Hz increased nonlinearly at the
simply supported boundary condition whereas it almost linearly increased at the fixed-free
boundary condition. In contrast, the actuating displacement of the PCAs depended on the applied
electric fields in a drive frequency range from 1 Hz to 10 Hz. However, the displacement behavior
of PCAs varied significantly at a higher range of drive frequency, i.e., beyond 15 Hz, due to the
occurrence of resonance. On the basis of these experimental results, the bending characteristics of
PCAs in relation to applied electric field, drive frequency, and boundary conditions were elucidated.
Buckling of Composite Thin-Walled Members
Authors: Lee Seung Sik , Yoon Soon Jong , Back Sung Yong
Published: March 2009

The use of pultruded fiber reinforced polymeric (FRP) members in civil engineering
applications can greatly reduce construction time and maintenance cost of structures, because
pultruded members have high specific strength and excellent corrosion resistance compared to steel
and concrete. Pultruded members for civil engineering application are mostly made of a polymeric
resin system reinforced with E-glass fibers and, as a result, they have low elastic moduli. Therefore,
stability is an important issue in the design of pultruded members. In this paper, the results of an
experimental investigation into the global buckling behavior of pultruded thin-walled members
subjected to axial compression are presented. The analytical solutions are validated through a
comparison with the results of FE analysis as well as the experimental results.
Preparation of Electrospun Protein Nanofibers with Multiwalled Carbon Nanotubes
Authors: Kang Min Sung , Yoon Seok Ho , Jin Hyoung Joon
Published: March 2009

A simple and mass producible method was developed to incorporate multiwalled carbon
nanotubes (MWCNTs) into electrospun silk fibroin (Bombyx mori) nanofibers. The process consists
of dispersing the acid-treated MWCNTs in an aqueous silk fibroin solution, and blending this
solution with a water-soluble polymer, poly(ethylene oxide) (PEO), followed by electrospinning of
the composite solution. The morphology and microstructure of the electrospun nanofibers were
characterized using field emission scanning electron microscopy (FESEM) and transmission
electron microscopy (TEM). The FESEM and TEM images show that the MWCNTs are embedded
along the nanofibers. Aqueous-based electrospinning of silk/PEO/MWCNTs composites provides
potentially useful options for the fabrication of biomaterial scaffolds, e.g. wound dressings, based
on this unique fibrous protein.
Compression Method for Superplastic Boronizing of DSS
Authors: Hasan Rafidah , Jauhari Iswadi , Ogiyama Hiroyuki , Ramdan Raden Dadan
Published: March 2009

Superplastic boronizing (SPB) is a new surface hardening technique utilizing the ultra
high plasticity phenomenon in metals in carrying out boronizing process. In boronizing, boron
atoms are diffused into the metal substrate to form a hard boride layer. In this research, a new
compression method for the SPB process was introduced. A clamp with an initial compressive load
of about 1960 N was used. Thermo-mechanical treated duplex stainless steel (DSS) with fine grain
microstructure which can show superplastic behavior at high temperatures was used as the
superplastic material. SPB experiments were conducted at temperatures between 1123 and 1223 K
for durations of 1 - 6 hours. The boronized specimens demonstrated thin, smooth and compact
morphology of boride layer. The boride layer thickness was within ±10 0m - ±46.2 0m. On the
boride layer, only the favorable single phase of Fe2B was detected. High value of surface hardness
was observed in the range of ±847 HV - ±2914 HV. The overall results from the study show that the
SPB process can significantly improve the surface properties of DSS.
Impact Characteristics of a Honeycomb Sandwich Panel
Authors: Lee Jae Heon , Cheong Seong Kyun , Shin Ki Hoon
Published: March 2009

The concept of light weight design will be very helpful for the tilting train to travel
around a curve at a faster speed because the light weight car body makes the center of gravity
lower. The impact characteristics of composite materials should be investigated because the impact
property of composites is very important. This paper investigates the low-velocity impact
characteristics and residual strength conducted on honeycomb sandwich panels. Low-velocity
impact tests were carried out at different energy levels on honeycomb sandwich panels using a
drop-weight apparatus. The impact-induced damages such as fiber breakage, matrix crack and
delamination are examined with an optical microscope apparatus. Residual strength was evaluated
by applying three point bending load to honeycomb sandwich panels. Experimental results show
that the residual strength is greatly reduced as the impact energy increases. From the microscopic
observation data, matrix crack, fiber breakage and delamination are the main impact damages of
honeycomb sandwich panels.
A Study on the Birefringence Measurement in Injection Molded Parts Using Two Different Laser Sources and R-G-B Separation of White Light
Authors: Kim Jong Sun , Hwang Chul Jin , Yoon Kyung Hwan
Published: March 2009

Recently, injection molded plastic optical products are widely used in many fields,
because injection molding process has advantages of low cost and high productivity. However,
there remains residual birefringence and residual stresses originated from flow history and
differential cooling. The present study focused on developing a technique to measure the
birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i)
the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of
both methods came from the fact that more information can be obtained from the distribution of
retardation caused by different wavelengths. The comparison between two methods is demonstrated
for the same sample of which retardation is up to 850 nm.
Direct CTE Measurement Technique for the MEMS Materials
Authors: Oh Chung Seog , Choa Sung Hoon , Lee Chang Seung , Lee Hak Joo
Published: March 2009

The accurate characterization of linear coefficient of thermal expansion (CTE) of thin
films is vital for predicting the thermal stress, which often results in warpage and failure of a
MEMS structure. In this paper, special emphasis is placed on the development of novel test
method to extend an ISDG (Interferometric Strain/Displacement Gage) technique to the direct and
accurate CTE measurement of MEMS materials, AlN and Au. The freestanding AlN and Au films
are 1 μm thick and 5 mm wide. Strain is directly measured by a brand-new digital type ISDG with
two Cr lines deposited on the specimen while heating a specimen in a furnace. The whole test
system is verified first by measuring the CTE for the NIST’s SRM (Standard Reference Material)
736 (Cu) block. The measured CTE is 17.3 με/oC up to 167 oC, which agrees well with the
NIST’s certified value. The CTE of Au is 25.4 ± 1.15 με/oC and that of AlN film is 3.77 ± 0.12
με/oC. The in-plane displacement resolution is about 5 nm at the best circumstances.
Measuring Strains for Hematite Phase in Sinter Ore by Electron Backscattering Diffraction Method
Authors: Sasaki Yasushi , Iguchi Manabu , Hino Mitsutaka
Published: March 2009

Based on the relationship between quantified blurring degree of Kikuchi bands obtained
by an electron backscattering diffraction (EBSD) technique and macroscopic strains measured by a
strain gauge, the local compression strain SEBSD in sinter ore has been evaluated under various
conditions. There is a good linear relationship between the SEBSD and the strains measured by a
strain gauge. The local strain SEBSD evaluated by EBSD patterns can be used as an index of local
strains.
Design and Fabrication of a Flexural Plate Wave Accelerometer
Authors: Lee Jin Seung , Kim Yong Chul , Lee Woon Seob , Lee Seung Seob
Published: March 2009

We design and fabricate a novel flexural plate wave (FPW) accelerometer which has
wide working range and improved sensitivity. A bridge as well as a rectangular diaphragm with a
proof mass has been considered for a wave propagation medium to enhance the performance. The
performance improvement is also verified with the bridge structure and the existence of the proof
mass in the simulation results.
A Novel PDMS Valveless Micropump with a Circular Lightweight Piezo-Composite Actuator
Authors: Nguyen Thanh Tung , Goo Nam Seo
Published: March 2009

This paper presents a design and performance evaluation of a valveless micropump
fabricated from polydimethylsiloxane (PDMS) based on molding techniques. A circular lightweight
piezo-composite actuator (LIPCA) was successfully developed for the actuating diaphragm of the
micropump. The LIPCA is a composite actuator designed and fabricated with piezoceramics in
combination with carbon fabric and glass epoxy. Numerical and experimental methods were used to
investigate the performance of the circular LIPCA. The LIPCA was glued to a PDMS membrane to
form the diaphragm of the micropump. The diaphragm has several advantages, such as high
displacement, dome-shaped deformation and geometrically independent actuation profile. The
diaphragm based on a LIPCA 9 mm in diameter produces a deflection of 27 μm at the applied
voltage of ± 200 V and a frequency of 1 Hz. The micropump has a maximum water flow rate of
0.95 ml/min and a maximum backpressure of 3.8 kPa. The merits of the present micropump are low
cost, ease of manufacturing and high level of effectiveness. The proposed LIPCA is proven to be a
promising alternative to the conventional piezoelectric actuator used in micropumps.
Micro-Deformation Measurement on a Specular Surface by DIC with Nanoparticles
Authors: Chen T.Y. , Huang I.T. , Chen B.H.
Published: March 2009

This paper proposes a method of applying Cu nanoparticles on the surface of miniature
specimen for micro-deformation measurement. The microscope image processing system, making and
preparation of Cu nanoparticles are described. Use of the nanoparticles on a miniature specimen to
determine the Young’s modulus is demonstrated through a tensile testing with an image resolution of 0.3
μm/pixel. Comparable well result is shown and discussed.
A Study on the Strength under Pressure of Micro Heat Exchanger
Authors: Son Taek Joon , Lee Young Shin
Published: March 2009

The strength of micro heat exchanger under pressure is studied in this paper. Micro heat
exchanger is made with brazing technology. It is constructed of stainless steel thin plates with micro
channels and in/out port for fluid flow. Micro channels in thin plates are formed by etching and all
parts including thin plates are joined by brazing. The study on the strength under pressure is
performed by structural analysis. For structural analysis, one layer of micro heat exchanger body is
considered. It is composed of thin plate with micro channel and brazing filler which is used to join
thin plates. This paper shows the tendency of stress behavior and gives design guideline of micro
heat exchanger.
Effect of Phase-Shifting Error on Deformation Evaluation Using Phase-Shifting Digital Holography
Authors: Kang Xin , He Xiao Yuan , Tay Cho Jui , Quan C.
Published: March 2009

Phase-shifting technique is an effect way to suppress the zero order diffraction and the conjugate term in
digital holography. However the phase-shifting error will influence inevitably the evaluation precision in practice
operation. In this paper, the deformation evaluation errors by means of two kinds of four-step phase-shifting
algorithms, which are in common use in digital holography, are analyzed and compared by computer simulation.
In addition, the phase-shifting errors may cumulate or not according to different phase-shifting techniques, and
both cases are considered in this paper. The results based on the digital in-line holography show that the two
four-step phase-shifting algorithms possess different sensitivity to the phase-shifting errors, and the preferable one,
which is more immune to the phase-shifting errors, is educed in conclusion.
Effect of Film Thicknesses of TbFe and SmFe on Magnetostrictions for Micro-Wireless Actuators
Authors: Lee Heung Shik , Cho Chong Du , Lee Usik
Published: March 2009

Silicon based magnetostrictive structures were fabricated for micro-wireless actuators,
and finite element models were developed to predict mechanical characteristics of the actuated
structures. These structures can be used to design wireless micro-vehicles and multi-function
packaged micro-devices. In the fabrication process, amorphous magnetostrictive films of the
optimized binary compound Tb0.4Fe0.6 and Sm0.47Fe0.53 were deposited with various thicknesses on
the silicon membrane by DC magnetron sputtering using cast composite targets. Magnetic fields
lower than 2KOe were applied for micro-system applications. These films have been tested in a
simple cantilever arrangement and the predicted magnetostrictions of the actuated membranes
through the developed FE models have been calculated.
Real-Time Shape Measurement by Unwrapping Method Using Aliasing
Authors: Fujigaki Motoharu , Toyotake Toshio , Matui Toru , Morimoto Yoshiharu
Published: March 2009

We previously proposed a real-time shape measurement method using two-component
synthesis grating projection. In the method, phase unwrapping of the projected grating is performed
by using aliasing of the Fourier spectrum of the grating images. It requires only 5 images obtained
for one-cycle phase-shifting. Each phase in the two-component can be extracted from only 5
phase-shifted grating images. In this paper, we propose a real-time shape measurement system. The
theory, the algorithm for the analysis and the experimental results are shown.
Electrostatic Ejection of Single-Walled Carbon Nanotubes Suspended in Solution
Authors: Kim Yong Jae , Lee Sang Hwan , Byun Do Young , Han Sang Joon , Yang Ji Hye , Ko Han Seo , Baik Seung Hyun
Published: March 2009

We propose to use electrostatic drop-on-demand devices, with precise metering and
accurate delivery capabilities, to manipulate single-walled carbon nanotubes suspended in solution.
The conductivity of the solution increases significantly by the addition of anionic surfactants and
nanotubes, generating favorable conditions for electrostatic ejection. This technique could find
applications, combined with chemical functionalization, in the fabrication of carbon nanotube field
emission devices as well as electronic circuits. hanseoko@yurim.skku.ac.kr
Characteristics of Nanosize Sn Powder Prepared by Spark Processing
Authors: Chang Sung Sik , Park Hye Jeong , Sakai Akira
Published: March 2009

The spark processing of metallic Sn yields a powder, which is a mixture of nanosize Sn
and crystalline SnO2. This paper reports the characteristics of nanosize Sn powders. Scanning
tunneling microscopy (STM) and transmission electron microscopy (TEM) studies reveal an
existence of spherical shaped nanocrystals ranging from 2 to 5 nm in size. In contrast the measured
surface area of spark processed Sn (sp-Sn) powders by BET is 27.7 m2/g and calculated average
size of sp- Sn is about 31 nm, which is close to one order of magnitude larger than the observed size.
Further, the characteristics of sp-Sn powders are studied by Raman, and differential thermal
analysis (DTA).
Design and Orthogonality Correction of a Planar Scanner for an Atomic Force Microscope
Authors: Lee Dong Yeon , Gweon Dae Gab
Published: March 2009

This paper shows a method of designing a nano-positioning planar scanner that can be used in a
scanning probe microscope. The planar scanner is composed of flexure guides, piezoelectric
actuators and feedback sensors. Furthermore, we used a motion amplifying mechanism in the
piezoelectric actuator to achieve a large travel range. We theoretically determined the travel range
of the total system and verified the range by using a program based on a finite element analysis. The
maximum travel range of the planar scanner was greater than 120 μm. A planar scanner of an
atomic force microscope can move samples with a few nm resolutions. To get stable AFM images
of small feature samples, a closed loop control could not be used due to large random errors of the
sensor. The orthogonality of a new planar scanner having a motion guide is measured and corrected
by using a simple electronic circuit in the open loop scanning to reduce the scanner artifact.
Serration Phenomena of AA5182/Polypropylene/AA5182 Sandwich Sheets
Authors: Kim Kee Joo , Kim Joo Sung
Published: March 2009

It has been reported that the 5182 aluminum sheet shows Lüders band because of
dissolved Mg atoms that cause fabrication process problem, especially surface roughness. The
examination of serration phenomena has been made after the tensile deformation of the AA/PP/AA
sandwich sheets as well as that of the 5182 aluminum. All sandwich sheets and the 5182 aluminum
skin showed serration phenomena on their flow curves. However, the magnitude of serration was
significantly diminished in the sandwich sheet with high volume fraction of the polypropylene core.
According to the results of the analysis of the surface roughness after tensile test, Lüders band depth
of the sandwich sheet evidently showed lower than that of the 5182 aluminum skin. The strain rate
sensitivity, m-value, of the 5182 aluminum skin was -0.006. By attaching these skins to the
polypropylene core, which has relatively large positive value of 0.050, m-value of the sandwich
sheets changed to the positive value.
Single-Step UV Nanoimprinting Lithography with Multi-Head Imprinting System and Its Applications
Authors: Lee Jae Jong , Lee Seung Woo , Cho Hyun Taek , Kim Gee Hong , Choi Kee Bong
Published: March 2009

The contact-based nanoimprinting lithography (NIL), such as thermal and/or UV nano-imprint,
has been well known as one of the next generation lithography alternatives. Especially, the UV nanoimprinting
lithography technology has the advantages in terms of process simplicity, low cost, high
replication fidelity, and relatively high throughput. The UV nanoimprinting lithography tool is built with
the characteristic functions like a self-alignment wafer stage, a nanoimprinting head unit, an alignment
system for multi-layer process, stamp/wafer chucking units, releasing unit, and anti-vibration unit, etc. This
UV-NIL tool is comprised of UV light source using mercury lamp, ultra-fine XY stage with nano-level
positioning accuracy, and self-adjusting flexure stage. The self-adjusting stage has the capability to control 6-
axes positions of wafer-holder. The UV-NIL tool can be used for fabrication of some functional
nanostructure-patterns i.e. nanosensor electrodes, optical grating patterns and 70nm rectangle patterns.
Non-Contact Single-Mode Guided Wave Technique by the Combination of Wavelength-Matched Laser Generation and Angle-Matched Leak Wave Detection
Authors: Kim Hyun Mook , Lee Tae Hun , Jhang Kyung Young
Published: March 2009

This paper proposes a non-contact single-mode guided wave technique, where the laser beam illuminated through the arrayed line slits is used as the transmitter, and the air-couple transducer is used as the receiver. The line-arrayed laser illumination has a wavelength-matching effect that can generate only a few modes. The air-coupled transducer detects the leaky wave of the propagated guided wave, and by tuning the detection angle of the transducer we can detect the selected single mode. The proposed technique is fully non-contact and is possible to avoid difficulty in the mode identification. The experimental results for a 1-mm thick aluminum plate prove the usefulness of the proposed method, and most especially, it shows that the method is powerful in the generation and detection of anti-symmetric modes of the lowest order.
Assessment of Fatigue Life for High-Temperature Pipeline Welds by Non-Destructive Method
Authors: Yoo Keun Bong , Choi Hyun Sun , Kim Eui Hyun , Cho Sun Young , Kim Jae Hoon
Published: March 2009

The objective of this study is to estimate the feasibility of X-ray diffraction method application
for fatigue life assessment of the high-temperature pipeline steel such as main steam pipe, re-heater pipe
and header etc. in power plant. In this study, X-ray diffraction tests using various types of specimen
simulated low cycle fatigue damage were performed in order to analyze fatigue properties when fatigue
damage conditions become various stages such as 1/4, 1/2 and 3/4 of fatigue life, respectively. As a result
of X-ray diffraction tests for specimens simulated fatigue damages, we conformed that the variation of the
full width at half maximum intensity decreased in proportion to the increase of fatigue life ratio. And also,
the ratio of the full width at half maximum intensity due to fatigue damage has linear relationship with
fatigue life ratio algebraically. From this relationship, it was suggested that direct expectation of the life
consumption rate was feasible.
Effect of High Glass Transition Temperature on Reliability of Non-Conductive Film (NCF)
Authors: Park Jin Hyoung , Chung Chang Kyu , Paik Kyoung Wook , Lee Soon Bok
Published: March 2009

Among many factors that influence the reliability of a flip-chip assembly using NCF
interconnections, the most effective parameters are often the coefficient of thermal expansion
(CTE), the modulus (E), and the glass transition temperatures (Tg). Of these factors, the effect of Tg
on thermal deformation and device reliability is significant; however, it has not been shown clearly
what effect Tg has on the reliability of NCF. The Tg of a conventional NCF material is
approximately 110°C. In this study, a new high Tg NCF material that has a 140oC Tg is proposed.
The thermal behaviors of the conventional and new NCFs between -40oC to 150oC are observed
using an optical method. Twyman-Green interferometry and the moiré interferometry method are
used to measure the thermal micro-deformations. The Twyman-Green interferometry measurement
technique is applied to verify the stress-free state. The stress-free temperatures of the conventional
and new Tg NCF materials are approximately 100oC and 120oC respectively. A shear strain at a part
of the NCF chip edge is measured by moiré interferometry. Additionally, a method to accurately
measure the residual warpage and shear strain at room temperature is proposed. Through the
analysis of the relationship between the warpage and the shear strain, the effect of the high-Tg NCF
material on the reliability is studied.
Research on 3D Geomechanics Model Test for a Large-Scale Offspur Tunnel Project
Authors: Zhang Qiang Yong , Li Shu Cai , Guo X.H.
Published: March 2009

Geomechanics model test has some distinctive advantages in simulating changing laws
of stress and strain of rockmass as well as failure mechanism of surrounding rockmass of tunnel. In
order to systematically study mechanics deformation properties of a large-scale offspur tunnel under
excavation state, we design and manufacture a large scale 3D model test rack installation with
hydraulic equipment. The test rack is 3.7 meters long, 2.2 meters wide and 4 meters high, which is
the largest 3D geomechanics model test rack in present Chinese communication trades. The
new-type similar material of model is a kind of cementitious composite which is mixed with iron
ore powder, blanc fix, quartz sand, rosin, industrial alcohol and gypsum powder. 3D geomechanics
model test for a large-scale offspur tunnel is carried out by utilizing the test installation and the
similar material. The original design and construction of the offspur tunnel has been effectively
optimized by results from model test.
Nondestructive Characterization of Degradation of EPDM Rubber for Automotive Radiator Hoses
Authors: Kwak Seung Bum , Choi Nak Sam , Choi Youn Joung , Shin Sei Moon
Published: March 2009

In this study, for EPDM rubber conventionally used as a radiator hose material the aging
behaviors of the skin part under the electro-chemical stresses were nondestructively evaluated. On
account of the penetration of coolant liquid into the skin part the weight of rubber specimens
degraded by ECD test increased, whereas their failure strain and IRHD hardness decreased largely.
The penetration of coolant liquid seemed to induce some changes in inner structure and micro
hardness distribution of the rubbers. Consequently, EPDM rubbers degraded by ECD could be
characterized nondestructively by micro-hardness and chemical structure analysis methods.