bluuebunny/crossref_metadata_2025 huggingface dataset:
Damage Analysis of Heat Resistant Steels
Authors: Bíró Tamás , Dévényi László
Published: March 2009

This paper shows the result of some metallographical examinations that have been
carried out on low-alloyed Cr-Mo-V heat resistant steel. The aim of this research is to present and
compare the advantages and disadvantages of the mainly applied metallographical methods. These
techniques are optical microscopy, scanning electron microscopy, replica method and special
applications of these methods. We have proved that using the investigated methods together gives
much more information about the lifetime of the specimen than using these techniques particularly.
Thermal and Metallurgical Modelling of Laser Transformation Hardened Steel Parts
Authors: Rowshan Reza , Baán Mária Kocsis
Published: March 2009

When applying laser transformation hardening (LTH) on a steel part the aim is to harden a localized area, which results in high hardness value for a defined width and depth of the material. To assure the hardened zone and keep the maximum temperature of the surface below the melting point we have used a finite element model (FEM) to compute the solution for heat distributions and the phase transformation of the material during LTH. Modelling results were used to introduce safe operating regions for LTH with different processing conditions. A problem associated with some LTH applications is the necessity to overlap the hardening passes. The temperature distribution of this phenomenon was also modelled using FEM which truly assist in finding optimum overlapping and technological parameters.
Current Research Activities on High Nitrogen Steel in Japan
Authors: Katada Yasuyuki
Published: March 2009

Nitrogen evolution research has been widely carried out in Japan after the Forth
International Conference on High Nitrogen Steels held in 1995 in Kyoto (HNS1995). The first
research forum on nitrogen evolution research has been started in The Japan Society of Corrosion
Engineering in 1996, followed by a series of research forums in the Iron and Steel Institute of Japan
(ISIJ). In the meantime, a pressurized electro-slag remelting furnace was newly developed in
National Institute for Material Science in 1998. A new research group regarding the availability
of nitrogen on the improvement in steel properties has been started in ISIJ in 2004. Current
research activities of the group cover the fabrication of HNS such as mechanical alloying,
pressurized ESR and nitrogen absorption, evaluation technologies of HNS such as microstructure
and precipitation behavior of nitride, mechanical properties, corrosion properties and physical
properties, joining/welding technologies. As one of the applications of HNS, Ni-free high nitrogen
steels with high strength, anti-corrosion, non-magnetic properties are very attractive in the fields of
bio/medical ones as anti-Ni allergy material. Recent research activities including some topics
mentioned above will be discussed.
Texture of AZ31 Magnesium Alloy Sheet Heavily Rolled by High Speed Warm Rolling
Authors: Sakai Tetsuo , Utsunomiya Hiroshi , Koh H. , Minamiguchi S.
Published: March 2009

Magnesium alloy sheets had to be rolled at elevated temperature to avoid cracking. The
poor workability of magnesium alloy is ascribed to its hcp crystallography and insufficient activation
of independent slip systems.
Present authors have succeeded in 1-pass heavy rolling of AZ31 magnesium alloy sheet below
473K by raising rolling speed above 1000m/min. Heavy reduction larger than 60% can be applied by
1-pass high speed rolling even at room temperature. The improvement of workability at lower rolling
temperature is due to temperature rise by plastic working. The texture of heavily rolled AZ31
magnesium alloy sheet is investigated in the present study.
The texture of sheets rolled 60% at room temperature was <0001>//ND basal texture. At the rolling
temperature above 373K, the peak of (0001) pole tilted ±10-15 deg toward RD direction around TD
axisto form a double peak texture. The texture varied through thickness. At the surface, the (0001)
peak tilted ±10-15 deg toward TD direction around RD axis to form a TD-split double peak texture.
The direction of (0001) peak splitting rotated 90 deg from the surface to the center of thickness.
Heavily rolled magnesium alloy sheets have non-basal texture. The sheets having non-basal texture
are expected to show better ductility than sheets with basal texture.
The Continuous Elimination of Inclusions in Molten Aluminum by Direct and Alternate Electromagnetic Force
Authors: Yoon Eui Pak , Choi Jung Pyung , Seo Yu Sik , Nam Tae Woon
Published: March 2009

In the casting Al alloys, Inclusions are formed by various melt treatment and the some alloying elements have a bad effect on quality of products. Generally, inclusions deteriorate mechanical properties of casting products as well as provide heterogeneous nucleation sites of hydrogen porosity. But the difficulty of removing it is the fact that the inclusions are measured generally small about 20㎛ in the melt. So, in this study, Experiments were carried out on commercial die casting aluminum alloy A383 (JIS: ADC 12). The separation system including a D.C. electric field with steady D.C. magnetic field was adopted for reduction of inclusion in molten Al alloy. Also the quantitative and qualitative analysis of inclusion in Al alloy was taken by using the PoDFA (Porous Disc Filtration Apparatus) and EPMA.
Modeling of Electrochemical-Mechanical Deformations of Ionic Polymer Metal Composite
Authors: Kang Sung Soo , Toi Yutaka
Published: March 2009

The bending deformation of the ionic polymer metal composite (IPMC) upon low electric
field is dominated by internal water redistribution. The one-dimensional finite element formulation is
conducted for the basic field equations governing electrochemical response of the IPMC. The
three-dimensional finite element analysis for the mechanical response of the IPMC beam is also
conducted. Some numerical studies are carried out to show the validity of the present formulation.
Preparation of High Lithium-Ion Conductive Ceramic
Authors: Oda Kengo , Takase Satoko , Shimizu Youichi
Published: March 2009

Lithium ionic conductive solid electrolyte discs based on NASICON-type
Li1+xGaxTi2-x(PO4)3 (x = 0.1 - 0.9) were prepared by a wet-chemical route at 1173 - 1273K.
Crystalline phase, density, and electrical conductivity of the sintered discs were systematically
investigated. Single phase of LiTi2(PO4)3 systems were obtained at the calcination temperatures
above 773K. Maximum conductivity 7.3 x 10-4 S/cm at 303K and activation energy of 0.30eV
were obtained for the Li1.25Ga0.25Ti1.75(PO4)3 discs sintered at 1223K.
Solvent Effect on Ion Hopping of Solid Polymer Electrolyte
Authors: Lee Yu Jin , Jo Yun Kyung , Park Hyun , Chun Ho Hwan , Jo Nam Ju
Published: March 2009

Solid polymer electrolytes (SPEs) based on poly (vinyl alcohol) were prepared with
dimethyl sulfoxide as a solvent. Prepared SPEs form the 'fast cationic transport process' and lithium
ion hopping through 'fast cationic transport process' is occurred. In this study, we observed the
dependence of ionic conductivity on the drying time of solvent and there was particular relationship
between ionic conductivity and the amount of residual solvent. Especially, we investigated the
influence of solvent on cation mobility in the ‘fast cationic transport process’ and we found that the
solvent acted as a bridge to connect neighboring ion aggregates and made the ion hopping easy.
The Discharge Properties of Nickel Sulfide Thin Film Prepared from Sulfidation of Nickel Foil
Authors: Kim Jong Seon , Lee Gun Whan , Kim Ki Won , Ahn Jou Hyen , Cho Gyu Bong , Ryu Ho Suk , Ahn Hyo Jun
Published: March 2009

The nickel sulfide (Ni3S2) thin film could be prepared from Ni/S double layer, which was
deposited on nickel foil using evaporation and sputtering. The nickel sulfide electrode was
discharged and charged between 0.6V and 2.6V versus Li/Li+ at room temperature. The nickel
sulfide film had the first discharge capacity of 270mAh/g, and two plateaus at 1.3V and 1.8V.
Electrochemical and Optical Properties of WO3 Prepared by Sol-Gel Coating
Authors: Kim Chang Yeoul , Cho Seong Geun , Park Seok , Lim Tae Yeoung , Choi Duck Kyun
Published: March 2009

Electrochromic WO3 thin film was prepared by using tungsten metal solution in hydrogen peroxide
as a starting solution and by a sol-gel dip coating method. The thermal analysis was conducted by
DSC/TG method. A DSC/TG analysis and the XRD patterns showed that a tungsten oxide crystal
phase was formed at 400oC. WO3 thin film when heat-treated at 300oC was amorphous and had a
better electrochemical property than that of the crystalline phase. Crystallization of tungsten oxide
decreased active sites of ion intercalation so that the current density decreased with heat-treatment
temperature.
Photocatalytic Degradation of NO2- by Fe3+-Doped TiO2 Nano Particles Prepared by Sol-Gel Method
Authors: Qiu Ke Hui , Zhang Chun Mei , Li Jun Feng , Li Qun , Zhao Jie
Published: March 2009

The preparation and the photocatalytic degradation NO2
- activity of Fe3+-doped
TiO2 nano-sized particles is reported in this paper. The TiO2 nano particles were prepared by
sol-gel method. The various influence factors about the synthesis process of the Fe3+-doped
TiO2 nano photocatalyst were controlled and investigated by XRD (X-ray diffraction), SEM
(scanning electron microscopy), and TEM (transmission electron microscopy) etc.. The results
show that the phase compositions, crystalline grain size, crystal structure , and photocatalytic
activity of the Fe3+-doped TiO2 particles prepared by the method depend on the synthesis
technology parameters such as calcination temperature, holding time, Fe3+ ions concentration
etc.. The influence factors of the preparation process has been discussed. The photocatalytic
decomposition of NO2
- ion into N2 and O2 using Fe3+ and Ce4+-doped TiO2 photocatalysts
were investigated under UV irradiation. It was fund that Fe3+-doped TiO2 photocatalysts shows
much higher photocatalytic activity than that of the Ce4+-doped TiO2 . The photocatalytic
decomposition effect of NO2
- ion is related to the crystalline grain size, irradiation time, and
the Fe3+ ions concentration. The Fe3+-doped TiO2 nano powders exhibited the photocatalytic
degradation NO2
- activity under UV light irradiation.
Removing Algae with Pt-Doped TiO2 Coatings on Foamed Glass
Authors: Song Jae Jin , Cho Sung Hun , Lee Soo Wohn , Kim Tae Ho , Hayashi Yamato
Published: March 2009

The commercial nano-sized TiO2 powder (P25) coated with PtO2 powder by a
sonochemistry method was immobilized on the foamed waste-glass substrates by using plasma
spray coating technology. The immobilized TiO2-Pt coatings were applied to treat both green tide
and red tide under illumination of an UV light. Their photocatalytic characterizations were
evaluated as functions of the number of residual algae, transmission as well as pH value with
illumination time. It’s found that the plasma sprayed Pt-doped TiO2 nanostructured coatings on
foamed waste-glass showed higher photocatalytic activity, which was effective to treat the green
tide and red tide.
Antimicrobial Characteristics of Metal Deposited ACF Filters
Authors: Yoon Ki Young , Byeon Jeong Hoon , Ko Byung Ju , Park Jae Hong , Park Chul Woo , Hwang Jung Ho , Yoon Hee Seung
Published: March 2009

Copper (Cu) and silver (Ag) known as antimicrobial materials were deposited on activated
carbon fibers (ACF) by an electroless plating method. The metal deposited ACF filters were
characterized by using SEM, EDX and XRD analyses. To verify the effects of metal deposition on the
adsorptive characteristics of ACF filters, the specific surface area and pore structure were determined
by BET equation and BJH method, respectively. The antimicrobial activities of metal deposited ACF
filters against E. coli, P. fluorescens, B. subtilis and M. luteus were characterized by modified
Kirby-Bauer method. By SEM-EDX and XRD analyses, it was confirmed that the electroless plating
method was adequate for deposition of Cu and Ag on the surface of ACF filters. BET and BJH
analyses showed that the micropore volume of metal plated ACF filters decreased compared to the
pristine ACF filter. The inhibition zones, which represent the antimicrobial effects, were formed
around the Cu and Ag deposited ACF filters whereas not in the case of pristine ACF.
Dome-Shaped High Power Transformer for Driving A 61 W T5 Lamp
Authors: Yoon Man Soon , Kim Il Ho , Ur Soon Chul
Published: March 2009

Processing and properties of a dome-shaped piezoelectric transformer with a composition
of 0.03Pb(Sb0.5Nb0.5)O3-0.03Pb(Mn1/3Nb2/3)O3-0.465PbTiO3-0.475PbZrO3 have been investigated.
A dome-shaped sample was fabricated by powder injection molding. The dimension of the domeshaped
sample was a 28 mm in diameter and 2.1mm in thickness with a curvature radius of 18 mm.
Finite element modeling for the complicated piezoelectric transformer was applied to simulate
strains and vibration mode in the sample. The high power characteristics of a dome-shaped
piezoelectric transformer were examined by the lighting test for 27 and 34 watt T5 circle lamps
connected in series. The series connected T5 circle lamps were successfully driven by the domeshaped
piezoelectric transformer with sustaining efficiency higher than 98.5%. The transformer
with ring(input)/dot(output) electrode ratio of 2.5 exhibited the maximum properties in terms of
output power, efficiency and temperature stability.
Effect of Aging on Damping Capacity of AZ91 Alloy
Authors: Jun Joong Hwan , Lee Geon Ha , Kim Jeong Min , Kim Ki Tae , Jung Woon Jae
Published: March 2009

Changes in microstructure and damping capacity with aging time for solutionized AZ91 (Mg-9%Al-1%Zn-0.2%Mn) alloy have been investigated based on experimental results from optical micrography, X-ray diffractometry, hardness test and damping capacity measurement vibrating in a flexural mode. Discontinuous β (Mg17Al12) precipitates form along the primary grain boundaries, the amount of which increases as the aging time increases. The hardness of α matrix with respect to aging shows a typical “S” shape, indicating a generation of fine continuous precipitation in the matrix during aging. The peak level of damping capacity for the AZ91 alloy is obtained after 1 hour of aging, over which the damping capacity becomes deteriorated continuously. The optimum density of continuous β precipitates with fine morphology, which may well act as pinning points for dislocation lines, might be responsible for the improvement of damping capacity.
Effect of Dam Design on the Fluid Flow in T-Shaped Continuous Casting Tundish
Authors: Hong Sung Hwan , Kang Jung Hoon , Han Jeong Whan
Published: March 2009

In the continuity casting technology of steel-manufacturing process, the tundish has two
important functions: the preservation and distribution of molten metal and the reaction container
able to perform float-out separation of nonmetallic inclusions. The residence time affects the
effective removal of the nonmetallic inclusions. In this study, a T-shaped tundish with a submerged
entry nozzle (SEN) and three strands was investigated for its ability to extend the residence time.
Analysis conditions were the shape of the dam which was transformed to three cases. Fluid flow
and non-metallic inclusion movement were also analyzed. The movement and removal of nonmetallic
inclusions was determined by residence time distribution (RTD) analysis. As a result, the
number of float-out, non-metallic inclusions was increased when the deviation of mean residence
time was reduced.
Effect of Rare Earth on the Microstructure and Performance of SnAgCuRE Solder
Authors: Zhang Jin Yong , Bai Gang , Zhang Ke Ke , He Yu Hang , Yang Shun
Published: March 2009

In the paper, the Sn2.5Ag0.7Cu solder alloy is selected out by comprehensive comparison.
Minute a mount of rare earth (RE) was added into Sn2.5Ag0.7Cu solder aiming at examining the
effect of different a mount of RE on microstructure,the physical properties and mechanical
properties of Sn2.5Ag0.7Cu solder.the aim is to define the optimization range of the RE addition.
Effect of the Size of the Reinforcement Phased on the Properties of Silica-Filled Composites
Authors: Kim Hyung Jin , Koh Sung Wi , Kim Jae Dong , Kim Byung Tak
Published: March 2009

In this study, the mechanical properties of silica-filled epoxy resin composites with
average silica particle diameter of 6-33m were investigated at ambient temperature and pin-ondisc
friction test was conducted for this. Experimental results demonstrated that mechanical
properties such as flexural strength, flexural modulus and critical stress intensity factor depend on
average particle diameter. The flexural strength decrease with increase of particle size whereas the
critical stress intensity factor increases with increases of particle size. Wear rates of silica-filled
composites are below a half those of unfilled epoxy. Fracture surface analysis was discussed based
on SEM examination.
Effect of Thermo-Mechanical Processing on Microstructure and Elastic Modulus of Metastable Ti-Nb-Si Alloys for Biomedical Application
Authors: Kim Han Sol , Kim Won Yong
Published: March 2009

This work describes the effect of microstructures on elastic modulus in Ti-26Nb-xSi alloy
(x=0.5~1.5at.%) prepared by arc melting, cold rolling and recrystallization heat treatment. OM
observation and x-ray diffraction analysis revealed that the microstructure of as-quenched sample
appeared to mixture appearance consisting of mostly bcc-structured β phase and small amount of
orthorhombic-structured α″ phase. After cold rolling, elongated structure parallel to the rolling
direction was observed, and equiaxed structure with the average grain size of about 20~30μm was
developed for the sample after recrystallization heat treatment. In as-quenched sample randomly
distributed feature of pole figure was characterized without showing a specific texture component. In
cold-rolled sample α-fiber, γ-fiber and rotated cube texture components were detected. After
recrystallization heat treatment the intensity of α-fiber texture component was markedly decreased,
while the rotated cube component becomes sharpened and γ-fiber component remains relatively
unchanged. The elastic modulus increased by cold rolling and then decreased by recrystallization over
the entire chemical composition range investigated. The variation of elastic modulus values was
interpreted in terms of changes in texture components depending on thermomechanical processing.
Characterization of Flame-Generated TiO2 Deposited Activated Carbon Fibers (ACF)
Authors: Park Jae Hong , Ji Jun Ho , Byeon Jeong Hoon , Lee Gyo Woo , Hwang Jung Ho
Published: March 2009

Even though activated carbon fibers (ACF) have been attractive due to high specific
surface area and uniform micropore structure, there are only a few reports about the photocatalyst
immobilization on ACF or their photodegradation behavior for removal of organic pollutants. In this
study, ACF were selected as adsorptive support for photocatalyst immobilization. As photocatalysts,
TiO2 nanoparticles were synthesized by using a N2-diluted and oxygen-enriched co-flow hydrogen
diffusion flame. The visible flame length of 150mm was obtained by direct photographs. Flame
temperature was measured by rapid insertion measurement technique with a R-type (Pt/Pt-13%Rd)
thermocouple which was in wire shape (127μm diameter). TiO2 particles were sampled by using a
high temperature particle sampler and then were coated on ACF filters. The sampling was carried out
at 70mm and 110mm above the burner. The structure of TiO2 particles was analyzed by XRD. TiO2
coated ACF filters were characterized by FESEM-EDX and BET analyses. TiO2 particles on ACF
filters were found to be agglomerated particles and the size of primary particles was approximately
50nm. The structure of TiO2 particle was anatase-phase crystalline structure. The specific surface
area of TiO2 coated ACF filter was enhanced to be 1700~1860m2/g, depending on the sampling
location, and the pores were micropores, regardless of the sampling location.
Fabrication of Lotus-Type Porous Ni-(15, 28 and 31) at.% Al Alloys by Unidirectional Solidification in Hydrogen Atmosphere
Authors: Hyun Soong Keun , Ikeda Teruyuki , Nakajima Hideo
Published: March 2009

Lotus-type porous Ni- (15, 28 and 31) at.% Al alloys whose long cylindrical pores
are aligned in one direction were fabricated by continuous zone melting technique under
high-pressure gas of hydrogen of 2.5 MPa. A part of 5-10 mm in length of the rod in the
vicinity of the coil was melted by high frequency induction heating, and was moved
downwards by electric motors at a constant velocity of 330 μms-1 to 500 μms-1 for
unidirectional solidification. The pores are formed as a result of precipitation from the
supersaturated hydrogen gas when the liquid metals dissolved with gas atoms is solidified.
The porosity and the pore size decrease with increasing aluminum content. An increase of
solidification velocity from 330 μms-1 to 500 μms-1 leads to a decrease of pore diameter and
an increase of pore number in the porous Ni-28at%Al.
Glass-Polydimethysiloxane Hybrid Microthermostat for Restriction Enzyme Digestion
Authors: Ko Yong Jun , Kim Dae Jin , Cho Woong , Ahn Yoo Min , Hwang Seung Yong
Published: March 2009

This paper reports a low-cost microthermostat that is able to maintain a constant
temperature necessary for restriction enzyme digestion. Polydimethylsiloxane (PDMS) and Pyrex
glass were used to make the microthermostat, because PDMS is a cheap and mass-producible
material and both PDMS and glass have very good biocompatibility compared to the more
commonly used silicon. A heater made of Au wiring patterned on Pyrex glass was used to control
the temperature. A PDMS replica molding technique was used to fabricate a reaction chamber with
3.6 μl capacity. Restriction enzyme digestion was performed by using the fabricated
microthermostat and by a conventional method. Then, using gel electrophoresis, we compared
results between the microthermostat and conventional methods. It was found that restriction enzyme
digestion using the microthermostat required 5 min of heating.
Processing and Properties of Al Based Amorphous/Crystalline Alloy Composites
Authors: Sung T.J. , Jung Taek Kyun , Kim Mok Soon , Yi Sung
Published: March 2009

Three types of composite materials, Al-10Ni-6Ce (at%)/pure Al (Vf=0.3), Al-10Ni-
6Ce/Al-3.6Mn (Vf=0.3) and Al-10Ni-6Ce/Al-5.5Mg (Vf=0.3), and monolithic Al-10Ni-6Ce alloy
were successfully fabricated to a fully dense rod-shaped bulk form having a diameter of about
10mm by adopting a powder forging or extrusion process using amorphous Al-Ni-Ce powder
together with crystalline pure Al, Al-Mn and Al-Mg powders. The monolithic Al-Ni-Ce specimen
forged at 648K showed a very high compressive strength of 1.3GPa without exhibiting any
compressive plastic strain. All of the composite specimens forged at 648K gained a compressive
plastic strain with the considerable sacrifice of strength. In contrast, Al-Ni-Ce/Al-Mg composite
specimen extruded at 648K showed a noticeably high compressive strength of 1.2GPa with the
compressive plastic strain of 0.5%. The extruded Al-Ni-Ce/Al-Mn composite specimen also
exhibited a considerably high compressive strength (1.1GPa) accompanied with plastic strain
(0.2%).
Synergistic Effect of Hybrid Filler Contained Composites on Thermal Conductivity
Authors: Kim Dae Hoon , Kim Min Hyung , Lee Ji Hoon , Lim J. H. , Kim K.M. , Lee B. C. , Park Joung Man , Kim Sung Ryong
Published: March 2009

Thermal conductivity of polyetheretherketone (PEEK) with fillers was investigated. By
adding the hybrid fillers to polymer the thermal conductivity of composites was increased
significantly. Thermal diffusivity of composites was measured using laser flash method. Synergistic
filler effect between particulate SiC and carbon fiber (CF) was observed for thermal conductivity.
In a PEEK based composite, thermal conductivity increased to 8.25 W/m-K for a 50 vol% hybrid
filler (SiC+CF) system, whereas the thermal conductivity of 40 vol% CF was 3.1 W/m-K and 50
vol% of SiC was 2.4 W/m-K, respectively. The use of hybrid filler was found to be effective in
increasing thermal conductivity of its composites due to formation of effective thermal conductive
path. Experimental results of two-phase system were compared with Nielsen prediction.
Application in Up-Flow Filtration of Filter Material for Urban Stormwater Control
Authors: Kim B.G. , Park H.J. , Lee Byung Cheol
Published: March 2009

In this research, a up-flow filtration device was developed for the on-site treatment of urban
stormwater runoff during storm events, and particle removal characteristic of porous polypropylene as
a filter material was experimentally examined. The up-flow filtration device showed high removal
efficiency, more than 90% (mainly 95-98%) of the SS concentration of influent particles. After the
sedimentation in the bottom part of up-flow filtration device, the up-flow filtration filled with porous
polypropylene material was able to remove more over 70% of the SS concentration in the up-flow.
The increase rate of captured particle amount retained in 10, 20 cm from the bottom of filter bed was
lower while flow rate increased. This is attributed to the fact that fine particles detached or not
removed by the bottom of filter bed were mainly retained in that section. The particles (mainly finer
particles) captures were increased by those particles (mainly large particles) retained in the initial
stage for influent particles. However, the improvement of particle removal efficiency (as SS
concentration) was not observed along with this phenomenon. The reason may relate to the fact that
the particles retained by the captured particles in the initial stage were fine particles.
Effect of Grinding and Extraction of Lignocellulosic Fiber on Oil Sorption
Authors: Lee Beom Goo , Lee Hyun Jong , Shin Dae Yong , Jeong Yeon Ho , Wu Jin Chen , Cho Dong Ha , Lee Kang Yol , Kim Dong Eun , Kang Wie Soo , Goh Young Gyun
Published: March 2009

Cotton, a lignocellulosic fiber and environment friendly natural material, was tested for its
ability to sorb diesel oil from the pure diesel oil bath and the diesel oil containing water bath. The
fiber was ground to disrupt the lumen structure or extracted with diethyl ether to remove wax from
cotton. Diethyl ether is an organic solvent and extracts only extractives in the cell wall. Oil sorption
capacity was the highest in control as 30.6 g/g in the pure diesel oil bath, and the lowest in ground
cotton as 0.8 g/g in the diesel oil containing water bath. Cotton is mainly composed of hydrophilic
components and sorb water more easily than oil. As a result diesel oil sorption capacity was much
higher in the oil bath than in the water bath. However, after grinding and passing through 20 mesh
screen (0.86 cm), wax is preserved but the lumen structure of cotton, of which the fiber length is about
18 mm, is disrupted by grinding and can not hold oil. Therefore, the diesel oil sorption capacity of
cotton was decreased significantly to 5.2 g/g in the pure diesel oil bath, and to 0.8 g/g in the water
bath, compared to those of control. And because wax is removed but lumen structure is not destroyed
after diethyl ether extraction, the diesel oil sorption capacity decreased slightly to 27.7 g/g in the oil
bath and to 7.5 g/g in the water. When cotton was presoaked in water, cotton sank during the
presoaking process, and so the oil sorption capacity could not be determined. Grinding, extractingand
presoaking all contributed to the changes in oil sorption capacity. The most significant change is
attributed to the reduction in the particle size of cotton.
Filtration Treatment of Pollutants in Urban Runoff Using Expanded Polypropylene Media
Authors: Kang Sung Won , Lee Byung Cheol , Kim Young Im , Yun Sang Leen , Park Yong Jin , Ahn Jae Hwan
Published: March 2009

Pollutants such as heavy metals and PAHs (Polynuclear Aromatic Hydrocarbons) in
stormwater runoff are a major problem in urban areas because these pollutants are discharged directly,
in most cases without any treatment, into the receiving environments like river and lake. Since many
of the pollutants are associated with suspended particulate materials in stormwater, SS (suspended
solids) is of acknowledged importance in stormwater runoff treatment by BMPs (best management
practices). Filtration, which is commonly used for removing particulate matter in stormwater
structural BMPs, depends on various factors (e.g., filter media size, flow rate, bed depth, filter surface
properties, etc). Especially, the characteristics of filter media are important factor affecting removal
efficiency of pollutants and replacement period of filter media in filtration performance. In this study,
EPM (expanded polypropylene media) as a filter media was manufactured at different expansion
ratios (i.e., 5, 10, 15 times) and tested in the up-flow filtration for removing pollutants in urban
stormwater runoff. The specific surface area of EPM10, EPM15, EPM30, EPM54 was 0.760 m2/g, 0.799
m2/g, 0.812 m2/g, 0.845 m2/g, respectively. The SS removal efficiency (64.1%) by EPM media was
higher than that (44.2%) by sand media. In case of EPM10 media, it took 175min of removal rate of
filtration system to be approached under 50% and EPM15 media was spent 110min. However, the SS
removal efficiency of EPM15 was over 10% higher than that of EPM10. The CODCr removal efficiency
of EPM media was also increased with increasing expansion rate. The experimental results in this
work show that pollutant removal efficiency by EPM media was increased with increasing expansion
ratio but replacement period of media was decreased. EPM media are expected to adsorb
non-biological organics like PAHs owing to its hydrophobicity.
Impact Sound Reduction Analysis of Concrete Slab Containing Artificial Lightweight Aggregates Fabricated Using a Sewage Sludge
Authors: Kim Kang Duk , Kang Seung Gu
Published: March 2009

The artificial lightweight aggregate (ALA) was fabricated using a sewage sludge produced
from a municipal wastewater, and impact sound reduction analysis for concrete slab made with the
ALA was done. Specific gravity of ALA decreased with the sewage sludge content due to the gas
bloating caused by melt films on the surface of ALA, which is formed easily because of low
temperature melting P2O5 and modifiers, CaO, MgO and K2O contained in the sewage sludge. And
water absorption of ALA increased with the sewage sludge content owing to open pores which were
formed by connecting an inside pore to a surface. A specific gravity of 10mm diameter ALA was
lower than that of 7mm ALA since a trapped gas could not escape from the core to the surface of ALA
due to longer moving distance. The ALA containing 20 wt% sludge sintered in a electric furnace
showed a specific gravity 15% lower and water absorption 50% higher than that of ALA sintered in a
rotary kiln. It might be attributed to easy release of gases during the pre-heat zone (600-1000oC) in the
rotary kiln, resulting in densification of ALA. Light and heavy weight floor impact sound of concrete
slab made with ALA were 63-72dB and 44-76dB respectively, similar to a general concrete slab. The
unit weight of concrete slab made with ALA, however, was 18% lower than that of general one owing
to the lightweight of ALA, so it could be suitable to applying for high-rise building.
Preparation of Adsorbent from Mine Residues
Authors: Shim Choon Hee , Lee Woo Keun , Ban Hyo Jon
Published: March 2009

The object of this study is to prepare adsorbents to remove heavy metals from
abandoned mine residues. There are many factors that affect the adsorptivity of prepared adsorbents.
The adsorptivity of prepared adsorbents is evaluated by cation exchange capatity(CEC). The
maxium CEC value is obtained by Dongwon mine residues treated with NaOH. The optimum
condition at that time is 75/25 wt% of mixing ratio of Dongwon mine residues and NaOH under N2
atmosphere at the activation temperature of 500°C. The CEC value was 95meq/100g at this
condition. 99.5% of Pb was removed under the condition of 50 mg/L, pH 5 and reaction time of 1hr.
Crystal Growth of Aragonite Precipitated Calcium Carbonate by Seeded Method
Authors: Park Woon Kyoung , Ahn Ji Whan , Ko Sang Jin , Han Choon
Published: March 2009

Characteristics of nucleation and crystal growth of aragonite precipitated calcium
carbonate in Ca(OH)2 – MgCl2 – CO2 system via a carbonation process is investigated. Aragonite
precipitated calcium carbonate with high aspect ratio was synthesized at high reaction temperature
and concentration of Ca(OH)2 slurry. The increase in crystal size with decreased in CO2 gas flow
rate can be explained by a decrease in the nucleation rate and an increase in the crystal growth rate
caused by a decrease in the dissolution rate to CO3
2- ion. In this study, crystal growth of aragonite
was investigated by adding aragonite seed. It was found that crystal growth of aragonite precipitated
calcium carbonate could be controlled by three-step carbonation process using reactants as the
Ca(OH)2. Aragonite with an aspect ratio from 5 to 27 and diameter from 3μm to 24μm was thereby
grown at a reaction temperature of 80°C and a CO2 flow rate of 50ml/min. It was also found that
MgCl2 aqueous solution can be used again in the carbonation process for the synthesis of aragonite
precipitated calcium carbonate.
Crystal Growth of KNbO3 by Solution-Dropping Method
Authors: Yoshiguchi Takashi , Ota Toshitaka , Adachi Nobuyasu
Published: March 2009

By the solution-dropping method imitating the growth of stalagmite in nature, piezoelectric
KNbO3 crystal was prepared onto a substrate by dropping metastable K2NbO3F aqueous solution.
The transformation from K2NbO3F to KNbO3 was accelerated by separately dropping H2O2 solution
at the same time. Under the conditions of K2NbO3F concentration of 4.2×10-2 mol/l, H2O2
concentration of 9mol/l, dropping rate of 1.7ml/min, dropping time of 2 h, and substrate
temperature of 20°C, KNbO3 crystals of 2 to 5μm and polycrystalline film composed of KNbO3
crystals of < 1μm were grown at aqueous temperatures of 20°C and 60°C, respectively.
Effect of Several Factors on the Synthesis of Calcium Hydroxide Prepared by Spray Drying Method Using Limestone
Authors: Choi Moon Kwan , Cho Jin Sang , Joo Sung Min , Park Jin Koo , Ahn Ji Whan , Kim Hwan
Published: March 2009

The purpose of this work is to influence of CaO concentrations of 5.0 wt.% and 10.0
wt.%, slurry feeding rate of 200~400 /min, rotating rate of drum of 5,000 and 10,000 rpm, inlet
and outlet temperature on the synthesis of Ca(OH)2 powder, and the synthesis of precipitated
calcium carbonate by carbonation process using Ca(OH)2 prepared by spray drying method. As the
feeding rate of slurry was increased, the particle size of Ca(OH)2 was decreased. Regardless of
rotating rate of drum, when the concentration of CaO was 5.0 wt.% and 10.0 wt.%, the morphology
of Ca(OH)2 showed spherical shape of 10~30 μm and 20~60 μm, respectively. The specific surface
area of synthesized Ca(OH)2 was 27~30 m2/g. When the initial reaction temperature was 11 °C and
30 °C, the shape and particle size of precipitated calcium carbonate synthesized in the carbonation
process showed the rectangular shape of 0.1~0.4 μm and the spindle shape of 0.5~1.0 μm,
respectively.
Fabrication of Al2O3 Microtubes Using Carbon Fibers and Al/ Al2O3 Mixed Powder in Solid-Vapor Reaction (SVR) Process
Authors: Myoung Sang Won , Jung Yeon-Gil , Lee Je Hyun
Published: March 2009

In this work, we report on the fabrication process of alumina (Al2O3) microtubes using
carbon fibers and aluminum/alumina (Al/Al2O3) mixed powder via a solid-vapor (SV) reaction. Al
and Al2O3 (α-Al2O3) were mixed in a 1:1 molar ratio, and heated to generate an AlO vapor. The
carbon fibers were heat-treated in the pre-carburized Al2O3 crucible at 1400°C for 9h with a heating
rate of 5°C/min in flowing argon (Ar) gas at 200 ml/min. Any carbon residues remaining in the core
after the heat treatment at 1400°C were burned off by subsequent calcination at 700°C for 3 h in air. A
post-heat treatment was conducted to convert the product to Al2O3. As a result, Al2O3 microtubes are
successfully synthesized via the SV reaction between carbon fibers and Al/Al2O3 mixed powder. The
TGA study shows that the AlO vapor is generated at temperatures above 750°C. As the calcination
temperature increases, carbon residues and Al4C3 peaks disappear in XRD patterns. Al2O3 microtubes
are synthesized at 1200°C, and show thinner wall thickness and undulating outer and inner surfaces
arising from the partial decomposition of Al2O3 microtubes.
Field Effect Transistor with ZnS Active Layer on ITO/Glass Substrate
Authors: Back In Jae , Gong Su Cheol , Lim Hun Seoung , Shin Ik Sub , Kuk Seoung Woo , Kim In Hoe , Jeon Hyeong Tag , Park Hyung Ho , Chang Ho Jung
Published: March 2009

The organic-inorganic field effect transistors (OIFETs) with ZnS active layer were
fabricated on the ITO/glass substrate using cross-linked PVP (poly-4-vinylphenol) as a gate insulator.
ZnS semiconductor films were prepared by the atomic layer deposition method. In the case of
cross-linked PVP film, the leakage current and capacitance were about 1× 10-8 A and 12 nF/cm2,
showing good gate insulation property. The carrier concentration and mobility of ZnS film deposited
on SiO2/Si wafer was found to be -9.4×1015 cm-3 and 49.0 cm2/ V·sec, respectively. For the OIFET
devices with ITO/PVP/ZnS/Ti:Au structure, the carrier mobility was about 1.9 cm2/V·sec. From the
AFM images, lower mobility in the OIFET device compared with ZnS film on SiO2/Si substrate may
be attributed to a rough surface morphology of ZnS film.
Growth Behavior of Carbon Tips Grown by Electron Beam Induced Deposition Method
Authors: Park Sung Hwak , Kim S.H. , Shin J.K. , Kim Jae Wan , Kang C.J. , Kim Yong Sang , Choi Y.J.
Published: March 2009

For the investigation of high aspect ratio structures with Atomic Force Microscope (AFM),
the cantilevers with very sharp and long tips are useful. Electron beam induced deposited(EBID) tips
can be simply fabricated by aligning the electron beam directly down the vertical axis of Si cantilever
and then irradiating a single spot on the cantilever for a proper time in the dominant atmosphere of
residual gases generated by the oil of the diffusion pump of the Scanning Electron Microscope
(SEM). However, the EBID tips cannot grow over 1&m in the residual gas atmosphere since there is a
little carbon source. We could enhance the height of tips by dipping the cantilever into the organic
solvents, drying it in the vacuum chamber and irradiating electron beam on it. With this process, we
could acquire the tip whose base diameter is 180nm and effective length is 3.18&m. In addition, we
observed that the growth behaviors of the tips are different in accordance with the species of the
solvents and we will discuss the effects of the organic solvents on the growth of the tips.
Phase Transformation of Nanocrystalline CdS Synthesized by Solvothermal Reaction
Authors: Thongtem Titipun , Phuruangrat Anukorn , Thongtem Somchai
Published: March 2009

CdS was synthesized by solvothermal reaction of CdCl2.2.5H2O and (NH2)2CS in
ammonia solution at 200 oC for 10 h. XRD, TEM and SAED show that the products are
nanocrystalline CdS. The phase is 100 % hexagonal (hcp) in pure water, gradually transformed into
cubic with the increase of NH3 concentration, and 100 % cubic in 25 % NH3 solution. By using
FTIR, no solvents were detected in the products. Raman analysis revealed the presence of 1LO
(longitudinal optical) and 2LO phonon peaks at 297.0 and 597.1 cm-1 for CdS (hcp), and 295.9 and
596.9 cm-1 for CdS (cubic), respectively. Strong peaks of the photoluminescent (PL) spectra were
detected at 450 nm for hcp, and 519 nm for cubic.
Porous Scaffold of n-HA/PA66/CS for Tissue Regeneration
Authors: Xiang Hong Zhao , Li Yu Bao , Mu Yuan Hua , Wang Xue Jiang , Li Hong
Published: March 2009

Nano-hydroxyapatite/polyamide66/chitosan composite (n-HA/PA66/CS) was prepared
by a co-precipitation method and porous scaffolds from n-HA/PA66/CS composite were prepared
by means of porogen–leaching method and were characterized by SEM, IR, XRD and universal
mechanical testing machine. IR and XRD analyses showed that some chemical bonds existed
between n-HA and polymers. Furthermore, macroporous structure of the scaffolds and mechanical
strength were tested with a changed ratio of porogens (PVP/NaCl). When the ratio of PVP and NaCl
is1: 6, the scaffold processed highly porosity and the pores were interconnected. The compressive
strength of the scaffold, can meet the requirement of tissue regeneration.
Supercritical Impregnation of Organic Phase Change Materials into Polyester Fiber
Authors: Ju Chang Sik , Kim Tae Won , Kim Si Young
Published: March 2009

A new technique preparing polyester fiber impregnated with organic phase change
material(PCM) was proposed and experimentally examined. The impregnation apparatus consisted of
a high pressure pump, two consecutive high pressure cylinders and auxiliary facilities. Polyester fiber
was bound on cylindrical stainless steel net inside equilibrium cylinder and was impregnated with
supercritical solution of PCM. PCMs, paraffin waxes and organic acids, were successfully
impregnated into the polyester fiber even at temperature below it’s glass transition temperature(Tg),
and the impregnated fibers showed high energy storage and release capacity around the melting point
of respective PCMs.
Surface Modification of Li (Co1/3Mn1/3Ni1/ 3)O2 Fine Powders Using Aqueous Al2O3 Sol
Authors: Kim Seon Hye , Shim Kwang Bo , Han Kyoung Ran , Kim Chang Sam
Published: March 2009

The surface of Li(Ni1/3Co1/3Mn1/3)O2 was modified with Al2O3 using aqueous alumina sol
and the electrochemical properties of the coated oxide were measured and compared with both
uncoated and Al-doped one. The alumina coated powder showed 185 mAh/g at first cycle, and 139
mAh/g after 50 cycles in the voltage range of 3.0~4.6 V at 1C rate. The initial discharge capacity of
the coated powder was slightly lower than that of the alumina doped one, but the cycle stability of the
coated was better than that of the doped.
Synthesis and Characterization of Sr1-xLaxFe12-yCoyO19 Nanoparticles Prepared by a Sol-Gel Method Using Propylene Oxide
Authors: Lee Su Jin , Paik Seung Uk
Published: March 2009

Nano sized ferrites, Sr1-xLaxFe12-yCoyO19 with improved magnetic properties have been
successfully synthesized by a simple sol-gel method forming Fe2O3 and Co2O3 gel using propylene
oxide as a gelation agent, followed by the addition of Sr2+ and La2+ ions. The magnetic behavior of
Sr1-xLaxFe12-yCoyO19 powders annealed at and below 900°C showed that an increase of the
annealing temperature resulted in the enhancement of the coercivity and the decrease of the
saturation magnetization. Especially the highest values of the coercivity and the saturation
magnetization of the ferrites with heat treatment were observed at temperature 150°C lower than
those of the previously reported values. The highest observed values of the coercivity and the
saturation magnetization of Sr0.6La0.4Fe11.8Co0.2O19 were 7,431 Oe and 52.3 emu/g at 900°C. The
ferrite powders annealed at 700°C have a crystalline structure of M-ferrite and showed spherical
particles shapes. The resulting spheres which were formed by the aggregation of nanoparticles with
size 3~5 nm have diameter around 50 nm.
Adhesion Improving of TiO2-Coated Fabrics
Authors: Nimittrakoolchai O. , Panyathanmaporn Thammarat , Jaroenworaluck Angkhana , Supothina Sitthisuntorn
Published: March 2009

Adhesion between TiO2 coatings and the fabrics was improved by using a silane adhesive
agent. To investigate a suitable method of applying adhesive agent, two different coating methods
were conducted. The silane was either mixed with Ti precursor for fabric dipping, or coated onto
the fabrics before dipping them in a Ti precursor. The effect of Ti precursor, sol and colloid, on
coating morphology was also studied. It was found that continuous coating with no cracking was
obtained when the fabrics were pre-treated with the silane. The TiO2 coatings had good adhesion,
regardless of the method of applying the adhesive agent. Thick, cracked coatings were obtained
from Ti colloid precursor while continuous coating was obtained from the Ti sol precursor.
Dependence of the Dielectric Properties of Pt/ZrO2/Si Capacitors Prepared by RF-Magnetron Sputtering on the Oxygen Partial Pressure and the Annealing Temperature
Authors: Lee Chong Mu , Park Anna , Park Su Young , Park Min Woo
Published: March 2009

Effects of the O2/Ar flow ratio in the reactive sputtering process and the annealing
temperature on the structure and surface roughness of ZrO2 films and the electric properties of
Pt/ZrO2/Si MOS capacitors in which the ZrO2 film was deposited by magnetron sputtering have
been investigated. The optimum process parameters of the Pt/ZrO2/Si capacitor based on reactively
sputtered- ZrO2 determined in such a way as the capacitance is maximized and the leakage current,
the oxide charge, and the interface trap density are minimized is the O2/Ar flow ratio of 1.5 and the
annealing temperature of 800°C
Phase Transformation of TiO2 in the Preparation of Pearlescent Pigment
Authors: Kim Tae Gun , Kim Hae Joeng , Kim Jeong Ja , Kim Sung Woong , Park Seong Soo , Hong Seong Soo , Lee Gun Dae
Published: March 2009

The TiO2/mica pearlescent pigments were prepared by the hydrolysis of TiOCl2 on the
natural mica (muscovite) followed by a calcinations process. The phase transformation of anatase to
rutile during calcination and their proportion in the TiO2 thin layer have been analyzed by XRD
measurements. The pH controlling during the initial stage of hydrolysis of TiOCl2 showed a
pronounced effect on the phase transformation of TiO2 on the substrate. This result may be due to
the fact that the pH controlling during the hydrolysis affects the crystal structure and size of TiO2.
The decrease in crystallinity and crystallite size of TiO2 resulted in lowering the temperature of
phase transformation from anatase to rutile.
Experimental Study on the Effects of the Performance of Polymer Electrolyte Membrane Fuel Cell
Authors: Kim Hong Gun , Kwac Lee Ku , Kang Sung Soo , Kang Young Woo
Published: March 2009

An experimental study is carried out to investigate the performance and the practical
application of polymer electrolyte membrane fuel cell(PEMFC) with the double-tied catalyst layers
in a Membrane Electrolyte Assembly (MEA). Characteristics of PEMFC depend highly on the
conditions such as gas pressure, temperature, thickness, supplied oxidant type (Oxygen/Air) as well
as humidification. They are controlled under the same condition for the comparison of the simulation.
Testing condition is fixed at 60sccm and 70°C in anode and cathode, respectively. The humidification
about 15% the performance is improved no humidification rather. The current density is increased
around 20% significantly when pure oxygen gas is provided as an oxidant. It is found that measured
values of unit cell voltage and current are influenced strongly by the type and amount of oxidant,
which give more enhanced values in case of oxygen compared to the ambient air as oxidant.
Influence of Hydrogen Sulfide in Fuel on Electric Power of Solid Oxide Fuel Cell
Authors: Nagamori Minako , Hirata Yoshihiro , Sameshima Soichiro
Published: March 2009

Terminal voltage, electric power density and overpotential were measured for the solid
oxide fuel cell with gadolinium-doped ceria electrolyte (Ce0.8Gd0.2O1.9, GDC), 30 vol% Ni-GDC
anode and Pt cathode using a H2 fuel or biogas (CH4 47, CO2 31, H2 19 vol %) at 1073 K. Addition
of 1 ppm H2S in the 3vol % H2O-containing H2 fuel gave no change in the open circuit voltage
(0.79 - 0.80 V) and the maximum power density (65 - 72 mW/cm2). Furthermore, no reaction
between H2S and Ni in the anode was suggested by the thermodynamic calculation. On the other
hand, the terminal voltage and electric power density decreased when 1 ppm H2S gas was mixed
with the biogas. After the biogas with 1 ppm H2S flowed into the anode for 8 h, the electric power
density decreased from 125 to 90 mW/cm2. The reduced electric power density was also recovered
by passing 3 vol % H2O-containing H2 fuel for 2 h.