bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclic Loading Behavior of Weak Reinforced Concrete Beam-Column Connections
Authors: Jiang Li Xue , Zheng Shi Ju , Zhang Wei Ping , Gu Xiang Lin
Published: March 2009

Eight weak reinforced concrete beam-column connections and two strong ones subjected to cyclic loads were tested. Effects of the one-way slab, top reinforcement ratio of the beam as well as the transverse reinforcement ratio inside the joint on the seismic behavior of reinforced concrete beam-column connections were primarily investigated. Tests results show that, when subjected to the negative moment, the beam flexural resistance increases notably due to the presence of the slab. However, failure mode of the weak connection transforms from the beam flexural failure to the joint shear failure, resulting from the increased joint shear brought by the slab participation. Besides, the presence of the slab reduces the ultimate relative rotation, ductility and energy-dissipation capacity of the connection. Generally, weak connections can receive more benefit from the one-way slab than strong connections. Connections with less amount of top reinforcement in the beam exhibit better ductility and energy-dissipation capacity, which indicates that it is not always good to strengthen the beam negative moment zones in existing structures. The transverse reinforcement inside the joint has little effect on the seismic behavior of the weak connection with a one-way slab.
A Comparative Research on Thermal Stresses Calculated from Different Element Models of a Concrete Continuous Box-Girder Bridge
Authors: Xu Feng , Wang Bo , Zhang Hai Long
Published: March 2009

According to the definition about the positive and negative gradient temperature distribution of structural cross section in the Chinese bridge design specification of General Code for Design of Highway Bridge and Culverts (JTG D60-2004), same temperature loads are applied to beam model and solid model of a typical there-span prestressed concrete continuous box-girder bridge to compare the numerical results of thermal stresses calculated from the two finite element models. The beam model is built through professional software Doctor Bridge that is prevailing in China for structural static analysis of bridge design, while the solid model is built using ANSYS. Between the two models, the numerical results of total thermal stress regarded to be added up with self-restrained stress and secondary stress are compared. The results from solid model are found to be much more conservative than from element model. The identity and diversity of the two series of results and the reasons for the generation of the diversity are expounded. It is recommended that the thermal stress calculated from solid model be better to be taken into account in a design so as to examine or amend the results that calculated through the professional software based on bar system FEM theory.
Tribological Performance of Translucent Dy-α-Sialon Ceramics
Authors: Liu Qian , Gui Lin Hua , Meng Jun Hu , Li Zhi Feng
Published: March 2009

A considerable test was made to figure out the effects of temperature and sliding conditions on the wear properties of the translucent Dy--Sialon. The friction coefficient was 0.54 at RT, 0.26 at 100 oC, and 0.81 at 600 oC respectively under an applied load of 5N. The wear rate was 6.91×10-15 at RT and 1.0×10-15 at 100 oC for the same Dy--Sialon sample. Obviously Dy-Sialon shows an excellent wear resistance under a suitable sliding condition, a load of 5N and at 100 oC. This appears attractive and important for Dy-Sialon ceramics to be used as a type of special wear resistant materials, with an optical translucence.
Thermal Conductivities of β-SiAlONs by Mechanically Activated Combustion Synthesis
Authors: Sivakumar R. , Aoyagi K. , Watanabe T. , Akiyama T.
Published: March 2009

–sialons (Si6-zAlzOzN8-z, z=3) synthesized by mechanically activated combustion synthesis (MA-CS) at a low N2 pressure of 1 MPa, were sintered by Spark Plasma Sintering (SPS) and thermal conductivity was measured at room temperatures. Specimens were fully densified at 1600oC for 10 mins. and showed only –sialon phases confirmed by x-ray diffraction patterns though un-reacted Si was present as impurities after MA-CS. Thermal conductivities increased with sintering temperature and had a maximum value 5.49 W m-1 K-1 for specimens sintered at 1700oC.
TEM Study of SiCN Glasses; Polymer Architecture versus Ceramic Microstructure
Authors: Kleebe Hans Joachim , Störmer Heike
Published: March 2009

Polymer-derived SiCN glasses with tailored polymer architectures were characterized by TEM and EF-SAED upon pyrolysis at 1000 °C and subsequent annealing. Main emphasis of this work was to verify as to whether the intrinsic amorphous structure of polymer-derived bulk materials exhibits different structural features upon pyrolysis, depending on the functionalities of the pre-ceramic polymer, and whether such characteristic features are maintained upon high-temperature anneal.
Nano-Grained Microstructure Design of Silicon Carbide Ceramics by SPS Process
Authors: Hojo Junichi , Matsuura Hiroyuki , Hotta Mikinori
Published: March 2009

SiC ceramics were fabricated from submicron- and nano-sized starting powders with Y2O3 and AlN additives by SPS process. The SPS process and the use of AlN additive were found to be effective for achieving the nano-grained microstructure with retarded grain growth. The nanoporous SiC ceramics were also obtained under the similar conditions. The optimum heating schedule and additive composition were proposed.
A New Technology with Porous Materials; Progress in the Development of the Diesel Vehicle Business
Authors: Ohno Kazushige
Published: March 2009

The long time of twenty years has passed since Diesel Particulate Filter (DPF) was
proposed before the practical use. The main factors that DPF has been put to practical use in this
time, are the same time proposal of the evaluation method of SiC porous materials linked to the
performance on the vehicle, and that the nature of thermal shock required for the soot regeneration
(combustion of soot) in the DPF is different from the conventional requirement for the rather rapid
thermal shock. For the requirements, these include demonstrating utmost the characteristic of SiC’s
high thermal conductivity, and overcoming the difficulty of thermal expansion of SiC-DPF by
dividing the filter into segments binding with the cement of lower Young’s modulus, and the
innovation of technology around the diesel exhaust system such as Common-Rail system. As the
results of these, the cumulative shipments of SiC-DPF have reached about 5 million, and it goes at
no claim in the market.
Developments in SiAlON Glasses and their Derivatives: Effects of Chemistry on Properties
Authors: Hampshire Stuart , Pomeroy Michael J.
Published: March 2009

This paper provides an overview of the preparation of M-Si-Al-O-N glasses and outlines the effects of composition on properties. As nitrogen substitutes for oxygen in sialon glasses, increases are observed in glass transition and softening temperatures, viscosities, elastic moduli and microhardness. If changes are made to the cation ratios or different rare earth elements are substituted, properties can be modified. The effects of these changes on mechanical properties of silicon nitride based ceramics and sialons are discussed. New research on M-Si-Al-O-N-F glasses is outlined.
Development in the Dressing of Super Abrasive Grinding Wheels
Authors: Denkena Berend , de Leon Luis , Wang B. , Hahmann Dennis
Published: March 2009

Harder workpiece materials and increased efficiency requirements for grinding processes make the use of super abrasive grinding wheels indispensable. This paper presents newly developed processes for the dressing of super abrasive grinding wheels. The different bond systems of grinding wheels require distinct dressing process. In this paper, dressing processes for metal and vitrified bonded grinding wheels are investigated. It introduces the method of electro contact discharge dressing for the conditioning of metal-bonded, fine-grained multilayer grinding wheels. A description of the essential correlation between dressing parameters and the material removal rate of the bond material is presented. The considered parameters are the dressing voltage, the limitation of the dressing current and the feed as well as the infeed of the electrode. For the grinding of functional microgroove structures, multiroof profiles with microscopic tip geometries are dressed onto the grinding wheel. For this, a profile roller in combination with a special shifting strategy is applied on finegrained vitrified bonded grinding wheels.
Study on Tribo-Fabrication in Polishing by Nano Diamond Colloid
Authors: Lin Wei Min , Kato T. , Ohmori Hitoshi , Osawa Eiji
Published: March 2009

Now that nano diamonds can be produced stably at low costs, there are growing needs to explore new areas of applications. This report discusses basic polishing experiments performed on nano diamonds to investigate their frictional and wear characteristics during polishing, and the results been obtained. The authors also propose a new terminology “tribo-fabrication” to mean an area of research on tribological phenomena seen with the interface of workpiece and tool surface in ultra-precision fabrication. These new term as well as the polishing characteristics of nano diamond are discussed.
An Experimental Study on High Speed Grinding of Granite with a Segmented Diamond Wheel
Authors: Xu Xi Peng , Zhu X.W. , Li Yuan
Published: March 2009

An experimental study was undertaken to investigate the grinding of granite at different grinding speeds over a wide range of material removal rates. A metal-bonded diamond blade was used as the grinding wheel with natural gray granite as the workpiece material. The tangential and normal force components were obtained through measuring the horizontal and vertical force components as well as the consumed power. The experiments were conducted with a constant wheel surface state to study the influence of grinding speed under different material removal rates. An additional test was also carried out to examine the grinding process while the wheel surface state progressively changed, in which case both forces and the morphologies of diamond grains were monitored at regular intervals. At a fixed material removal rate, both the tangential and normal forces reduced slightly with the grinding speed. But the specific energy increased greatly at higher grinding speeds especially at a shallower maximum grain depth of cut.
Super Polishing Behaviour Investigation of Stainless Steel Optical Lens Moulding Inserts
Authors: Liu Kui , Ng S.T. , Shaw K.C. , Lim G.C.
Published: March 2009

Super polishing experiments were carried out to investigate the effects of polishing parameters on surface quality of stainless steel lens moulding inserts, and to optimize polishing conditions. Experimental results indicated that optical quality surface of stainless steel lens moulding inserts can be achieved through a two-step polishing process: fast polishing with a soft wood head and coarse diamond paste, and fine polishing with a nylon-covered steel ball head and fine diamond paste. A diameter of 20 mm stainless steel lens moulding insert with a surface roughness Ra of 7.6 nm has been successfully achieved using the two-step super polishing process.
Review on Selecting Raw Materials of Crack-Resistant Concrete
Authors: Zhou Shi Hua , Wang Ying Chun , Yang Hua Quan
Published: March 2009

Modern concrete is more than simply a mixture of cement, water and aggregates; it also contains more and more mineral components, chemical admixtures, so the problem of concrete cracking will be more complicated. This paper mainly discussed the relationship between the character of various raw materials and the crack resistance of concrete. In order to improve the crack-resistant and durability of concrete, the technology for selecting raw materials of crack-resistant concrete is put forward.
Experimental Studies on the Volume Change of the Super High Strength and High Performance Concrete
Authors: Xing Feng , Yin Hui , Wang Chong
Published: March 2009

Volume change of super high strength and high performance concrete with different binder-aggregate ratios and different curing conditions were investigated in this paper, and the volume changes of cement paste and mortar were also tested. The results indicated that the change of cement paste was much higher than mortar and concrete under the same curing conditions；the curing condition has a obvious influence on the volume change; there was a moisture swell for the water curing concrete; the specimens with limestone powder have smaller volume change than those specimens without limestone powder. The volume change mechanism was explained, and the effect of limestone powder on the volume change was also discussed.
Investigation of the Ability of Alkali Binding by C-S-H and C-A-S-H Gels
Authors: Yang Li Rong , Feng Xiao Xin , Wang Chun Mei , Cai Ji Wei
Published: March 2009

The binding of sodium and potassium into cement paste influences the performance of concrete: for example, alkali balances between solid and paste constituents and pore fluid affect the potential for alkali aggregates reaction. However, quantification of the binding potential into paste solids has proven to be difficult, although much empirical data are available from pore fluid analyses. In this study, single-phase homogeneous C-S-H phases have been prepared at Ca: Si molar ratios (C/S) of 1.8, 1.6, 1.3, 1.0 and 0.8 and reacted with four alkali hydroxide concentrations, both NaOH and KOH, between 10 and 300 mM. A steady-state alkali partition is attained in less than 4d at 20°C by flame emission spectroscopy and the ξ potential of C-S-H and C-A-S-H gel unreacted and reacted with alkali hydroxide are measured. The results indicate：alkali binding into the C-S-H and C-A-S-H gel improves as its C/S decreases；Al3+ has been introduced to form C-A-S-H gels, and the influence of Al3+ on alkali sorption properties was determined: the replacement of Si4+ by Al3+ and Na+ or k+ markedly increases alkali binding and decreases the ξ potential of gel；the more Ca:Si ratio，the less alkali binding, the more ξ potential of gel.
Relation of Permeability by High Hydraulic Method and Chloride Ion Diffusion Coefficient of Concrete
Authors: Ge Yong , Fan Jie , Yuan Jie , Yang Wen Cui , Zhang Bao Sheng , Yu Ji Shou
Published: March 2009

Permeation length, permeation coefficient of water permeated into concrete and chloride ion diffusion coefficient of C30, C45 and C60 concrete were studied by high hydraulic method (0.5MPa~25MPa) and quick method of testing chloride ion diffusion respectively, and relationship of concrete permeability tested by two methods was analyzed too. High hydraulic method can distinguish permeability of concrete with different strength or air content and it is a quick and effective method to fast test and evaluating permeability of concrete. The results showed that high hydraulic method is applicable for evaluating permeability of concrete, with advantages of short testing period, easy operating and simple pretreatment of concrete specimens. Permeation coefficient or permeation length of water permeated into concrete exhibited linear relationship with chloride ion diffusion coefficient of concrete. It is applicable for evaluating permeability of concrete using quick method of testing chloride ion diffusion.
Simulation Analysis Procedures on the Damage by Fire to High-Performance Concrete
Authors: Zhao Jie , Peng Gai Fei , Guo Zhan Qi , Chen Xian Wei
Published: March 2009

This paper presents the whole procedures that should be followed when carrying out the simulation analysis on the damage by fire to high-performance concrete (HPC). The whole procedures consist of temperature field determination, mechanical analysis, identification of damage to HPC related to thermal and mechanical behavior, structural behavior simulation and cooling stage simulation analysis. That the first two parts are essential to the whole analysis has been pointed out. The present simulation analysis situation is analyzed as well.
Research on High Performance Concrete Used in Concrete-Filled Steel Tube Column Structure Experiments for Guangzhou Xita Project
Authors: Yang Yi Bo , Liang Song , Mo Hai Hong , Chen You Wen , Chen Jun Sheng , Ba Ling Zhen
Published: March 2009

Guangzhou Xita Project uses a special exterior frame which consists of huge inclining concrete-filled columns. To ensure the engineering quality and select the suitable concrete-filled steel tube column structure, two concrete-filled steel tube column structure experiments have been carried out. To ensure the quality of the concrete-filled steel tube column structure experiment, the C100, C90 and C70 high performance concrete experimental research have been done specially, and the result of the experimental researches has been used in concrete-filled steel tube column structure sample successfully. The raw materials, mixture proportions and performance of the high performance concrete were discussed in this paper.
Technical Features and Countermeasures of High Strength and High Performance Concrete
Authors: Feng Nai Qian , Ye Hao Wen
Published: March 2009

In this paper, the technical problems are discussed, and a couple of countermeasures are proposed. To solve the problems of HPC, such as autogenous-shrinkage caused cracking, cracking caused by swelling, and high plastic viscosity, the key parameters are water content and cement content in mix proportion. Coarse aggregate should comprise of two grades. Such HPC can inhibit autogenous-shrinkage caused cracking, cracking caused by swelling, and lower plastic viscosity and improve pumping performance. Incorporate polypropylene fiber can prevent explosive spalling under high temperature.
Investigation of the High Strength Steel Al-Si Coating during Hot Stamping Operations
Authors: Borsetto Francesca , Ghiotti Andrea , Bruschi Stefania
Published: March 2009

To improve the low formability that HSS sheets exhibit at room temperature, innovative forming technologies like the hot stamping process are currently applied. In order to avoid scaling and decarburization during the heating step, metal sheets coated with a specially developed Al-Si coating are utilized. In the present work the coating characteristics in terms of morphology, surface roughness and tribological behaviour are investigated as function of heating temperature, holding time and cooling rate that are typical of hot stamping processes.
Optimization of X-Ray Pole Figure Measurement
Authors: Tarkowski Leszek , Laskosz L. , Bonarski Jan T.
Published: March 2009

The traditionally applied registration method of the back-reflection pole figure is based on the equiangular measurement lattice. It determines also the equiangular character of presentation of measurement results in form of stereographic projection, termed as the pole figure. The mentioned registration mode is characterized by an unequal density of the measurement points on the pole figure. It is the evident disadvantage of the traditional registration mode. In order to
eliminate the drawback, and to increase the efficiency of the measurement procedure, an optimization of the registration method was made. The optimization consists in dividing a reference sphere of the stereographical projection into uniform regions, so called equal solid angles (ESA). As a result of the applied optimization, over 40% reduction in number of the measurement points and in the registration time at preserved pole figure quality was obtained. For verification of the new
solution, a set of experimental pole figures of cold rolled copper by the traditional mode as well as the introduced ESA one was recorded. Comparison of the results of texture analysis based on the orientation distribution function was carried out. The results of measurements performed by the ESA method confirm the efficiency of the introduced optimization.
Performance Stability of Microfocusing Source and Multilayer Optics Based X-Ray Diffraction System
Authors: Kim Bonglea , Verman Boris , Jiang Licai
Published: March 2009

X-ray diffraction systems based on a microfocusing X-ray source and multilayer
side-by-side optics are suitable for X-ray diffraction studies in a variety of fields, such as protein crystallography, due to their compactness and low cost in maintenance. However, new problems can occur, such as intensity instability induced by source position drifting. Various investigations for the reasons and the consequences of the instability are presented in this paper. Feasible solutions and suggestions are given to obtain more stable system performance.
Structure and Phase Composition Study of Thin CdS and CdxZn1-xS Films
Authors: Maximovski E.A. , Fainer N.I. , Rumyantsev M.
Published: March 2009

Thin nanocrystalline CdS and CdxZn1-xS films have been synthesized on InP(100), Si(100), GaAs (100), sapphire(100) and fused silica substrates at low pressure (5 × 10-2-2 × 10 -1Torr)and in the temperature range of 473-673 K by remote plasma enhanced chemical vapor deposition (RPECVD) using Cd(S2CN(C2H5)2)2·C12H8N2 and Cd/Zn(S2CN(C2H5)2)2·C10H8N2 as single-source precursors. The influence of deposition conditions and type of substrates on physical and chemical properties of these films has been studied by X-ray diffraction of synchrotron radiation, HREM, SEM, SAED, ellipsometry, IR- and Raman spectroscopies, and EDS.
Ab Initio Determination of a New Complex Structure (55 Non-Hydrogen Atoms) from Synchrotron Powder Data: An Uncommon Nickel Succinate, Ni7(C4H4O4)4(OH)6(H2O)3•7H2O
Authors: Guillou N. , Livage C. , van Beek W. , Férey G.
Published: March 2009

Ni7(C4H4O4)4(OH)6(H2O)3 . 7H2O, a new layered nickel(II) succinate, was prepared hydrothermally (180°C, 48 h, autogenous pressure) from a 1:1.5:4.1:120 mixture of nickel (II) chloride hexahydrate, succinic acid, potassium hydroxide and water. It crystallizes in the monoclinic system (space group P21/c, Z = 4) with the following parameters a = 7.8597(1) Å, b = 18.8154(3)Å, c = 23.4377(4) Å,ϐ = 92.0288(9)°, and V = 3463.9(2) Å 3. Its structure, which contains 55 non-hydrogen atoms, was solved ab initio from synchrotron powder diffraction data. It can be described from hybrid organic-inorganic layers, constructed from nickel oxide corrugated chains. These chains are built up from NiO6 hexameric units connected via a seventh octahedron. Half of the succinates decorate the chains, and the others connect them to form the layers. The three
dimensional arrangement is ensured by hydrogen bonds directly between two adjacent layers and via free water molecules.
The Structure Investigation of Copper, Nickel and Iron Hexacyanometalates from Conventional X-Ray Powder Diffraction Data
Authors: Petrovic-Prelevic Irena , Widmann Antje , Kahlert Heike , Wulff Harm , Scholz Fritz
Published: March 2009

The crystal structure of new Prussian blue analogue samples,
KCu[Fe1-x Cox(CN)6], KNi[Fe1-x Cox(CN)6] and Fe[Fe1-x Cox(CN)6], was solved on the base of the model from Keggin and Miles [1] and refined by the Rietveld method [2] from conventional X-ray
powder diffraction data. These compounds form mixed crystals for all Fe/Co ratios. The crystal structure of the KCu[Fe0.3Co0.7(CN)6], KNi[Fe0.3Co0.7(CN)6] and Fe[Fe0.8Co0.2(CN)6] is presented in detail. For both potassium containing compounds the disorder in the potassium arrangement is the most obvious characteristic.
Docetaxel (Taxotere® Trihydrate) Forms: Crystal Structure Determination from XRPD & XRSCD Data
Authors: Zaske L. , Perrin M.-A. , Daiguebonne C. , Guillou O.
Published: March 2009

Docetaxel (form A), a stoichiometric hydrate containing three water molecules
per molecule of drug substance (Taxotere®), is thermodynamically stable under ambient conditions of pressure, temperature and relative humidity. In order to gain a better understanding of docetaxel system at the atomic scale a structural study was performed. Due to strong anisotropy of crystals (thin plates), the crystal structure of docetaxel (29 degrees of freedom) was solved and refined using high resolution XRPD data applying an ab initio direct space method. In parallel, an in-depth crystal growth study was carried out until single crystals suitable for XRSCD structural resolution were obtained: surprisingly, a new polymorph of docetaxel, called form B, was isolated.
Fabrication of SiO2-Coated Magnetic Nanoparticles for Applications to Protein Separation and Purification
Authors: Yun S.H. , Lee C.W. , Lee Jai Sung , Seo C.W. , Lee E.K.
Published: March 2009

Coating of -Fe2O3 nanoparticles with SiO2 layer by wet chemical synthesis and its
applications to protein separation and purification were investigated. The average particle size of
-Fe2O3 core was 20 nm and SiO2 layer thickness was 5 nm. The band of OH- radicals on SiO2 layer
was detected between 3600 and 3200 cm-1 in wave numbers, which showed that the surface property
of coated nanoparticles was similar to that of conventional fumed silica. Finally, the feasibility of
-Fe2O3/SiO2 nanoparticles for magnetic separation media in various bio processes was discussed in
terms of structural and functional properties such as pore structure and magnetic properties.
Influence of Annealing Temperature on Magnetic Properties in Co-Based Amorphous Ribbons
Authors: Jin Li , Rheem Y.W. , Kim Cheol Gi , Sun De Sheng , Kim Chong Oh , Yu Seong Cho
Published: March 2009

The magnetic properties were investigated on Co66Fe4B15Si15 amorphous ribbons of
annealed at temperature range from 473 K to 773 K in vacuum (A-batch) and open air (B-batch).
Static permeability from domain wall motion decreases with annealing temperature both in A- and
B-batch sample. The permeability from magnetization rotation increases up to 700 K annealing
temperature, but then decreases. The GMI profiles show a symmetric curve in A-batch samples
irrespective of annealing temperature. In B-batch samples, symmetric profiles are shown up to 650 K
annealing temperature, while they becomes asymmetric for further annealing temperature, due to the
exchange bias-field induced by surface crystalline layer.
Planar Hall Effect of GaMnAs
Authors: Kim K.H. , Lee Kyung Jong , Kim Dae Joon , Kim H.J. , Ihm Young Eon
Published: March 2009

Anisotropy magneto-resistance and planar Hall-effect of ferromagnetic GaMnAs
epitaxial films were investigated. The films were grown on 2 o off-cut GaAs (001) substrate in an
optimized growth condition via low temperature molecular beam epitaxy. The GaMnAs layer
revealed an easy axis along the (2x4) reconstruction direction of the substrate or along the off-cut
direction. The large value of the anisotropy magneto-resistance ratio of ~7 % was realized by a
well-alignment of the easy axis of the homogeneous ferromagnetic GaMnAs layer with the current. It
also gives a very high planar Hall resistance ratio of ~500 %.
New Manufacturing Process of Nickel-Free Austenitic Stainless Steel with Nitrogen Absorption Treatment
Authors: Kuroda Daisuke , Hanawa Takao , Hibaru Takaaki , Kuroda Syuji , Kobayashi Masaki , Kobayashi Takeshi
Published: March 2009

Ingots of ferritic stainless steels, Fe-24Cr and Fe-24Cr-2Mo in mass%, were worked to
various dimensions for test specimens. Nitrogen was absorbed by the specimens in a furnace filled
with nitrogen gas with a pressure of 101.3 kPa at 1473 K to develop a simple and convenient
manufacturing process of nickel-free austenitic stainless steels. Ferritic Fe-24Cr and Fe-24Cr-2Mo
were austenitized with nitrogen absorption to a 2-mm depth from the surface. The hardness, tensile
strength, 0.2% proof stress, and elongation to fracture increased, and the reduction of area decreased
in the alloys by austenitization due to nitrogen absorption. The tensile strength and 0.2% proof stress
of these alloys with nitrogen absorption for 129.6 ks were much larger than those of 316L steel, while
the elongation to fracture was much smaller than that of 316L steel. Therefore, small devices and parts
with a maximum thickness or diameter of 4 mm were manufactured with this process in this study
Densification and Mechanical Property of Nanostructured NiAl Produced by Mechanical-Alloying and Spark-Plasma Sintering
Authors: Kim Ji Soon , Jung S.-H. , Kim Young Do , Lee Chung Hyo , Kwon Young Soon
Published: March 2009

Mechanically-alloyed NiAl powder was sintered by Spark-Plasma Sintering (SPS) process.
Densification behavior and mechanical property were determined. Above 97% relative density was
obtained after sintering at 1150oC for 5min. Crystallite size determined by the Scherrer method was
approximately 80 nm. TEM observation revealed a relative larger crystallite size. X-ray diffraction
analysis showed that the sintered bodies were composed mainly of NiAl phase together with Ni3Al
phase. Sintered NiAl body showed an average Vickers hardness of 555Hv, transverse-rupture
strength of 1393MPa, 4-point-bending strength of 1100MPa, and fracture toughness of 19.9MPa
m-1/2
Mechanochemical Synthesis of Nano-Sized CeO2 and its Application for CMP Slurry
Authors: Lim Geon Ja , Lee Jong Ho , Kim Joo Sun , Lee Hai Won , Hyun Sang Hoon
Published: March 2009

Nano-crystalline CeO2 was synthesized by the mechanical milling and subsequent
heat-treatment from the mixture of Ce(OH)4 as precursor, and NaCl as diluent. The diluent provided
diffusion barrier during milling and heat-treatment, which was easily dissolved out by deionized
water. The size of crystallite and the strain variance of CeO2 were depended on the temperature and
heat-treatment time: increased with the temperature (400~700oC) and time (1~24 hours) increasing,
and saturated near at 20nm in size owing to the densification of diluent. The synthesized
nano-crystalline CeO2 powder was applied as an abrasive in CMP (Chemical Mechanical
Planarization) slurry. When blanket-type SiO2 and Si3N4 wafers were polished with the slurries, the
removal rates (RR) of SiO2 and Si3N4 wafers and selectivities (RRSiO2/RRSi3N4) were influenced by
synthetic condition of abrasive, the suspension stability and the pHs of slurries.
Fabrication of Oxide/Semiconducting Coaxial Nanotubular Materials Using Atomic Layer Deposition
Authors: Jeong D.K. , Park N.H. , Jung S.-H. , Jung Woo Gwang , Shin H. , Lee J.G. , Kim J.Y.
Published: March 2009

Novel fabrication routes of oxide/semiconducting hybrid nanotubes or coaxial
nanocables with 30~200 nanometers of radius and ~10 micrometers of length using atomic layer
deposition (ALD) and soluble nano-templates was reported. In order to fabricate the hybrid
nanotubes using nanotemplates, which were treated with surface modification using SAMs in order
to achieve selective deposition only onto inner wall of the template. Deposition of metal oxide
layers (TiO2, ZrO2) conformally and uniformly onto the wall of templates using ALD. To fabricate
metal oxide/CdS nanocables or coaxial nanotubes, CdS was deposited onto metal oxide nanotubes
by chemical bath deposition. Coaxial nanocables was also 30-200 nm in diameter and 1-10

in
lengths.
Microstructural Evolution on Dissolution of Commercial Calcium Phosphate Ceramics
Authors: Seo Dong Seok , Kim Hwan , Lee Jong Kook
Published: March 2009

Three types of calcium phosphate ceramics, i.e. tricalcium phosphate, biphasic calcium
phosphate and near stoichiometric hydroxyapatite, were prepared by sintering at 1200oC for 2 h in
air with moisture protection. Their dissolution processes were investigated by taking microstructural
observations after immersion in distilled water for 3 or 7 days. It was found that the surface
dissolution of the ceramics was initiated at grain boundaries and generated many separated grains.
In case of the materials with high porosity, the residual pores on the surface appeared to be a
primary defect site where the dissolution starts although the soluble compound was existed on the
matrix.
Effects of Layered Silicate on Nanoscopic Internal Structure and Morphology in Polymer Blend
Authors: Lim S.T. , Choi Hyoung Jin
Published: March 2009

Organically modified layered silicate was introduced into miscible poly(ethylene oxide)
(PEO) / poly(methyl methacrylate) (PMMA) blends for the synthesis and characterization of
polymer/clay nanocomposite through solvent casting method. As a part of our continuous efforts on
the study of nanoscopic internal structures and changes of material properties caused by the presence
of organically modified layered silicate, we systematically investigated the characteristic
morphological changes and internal structures with scanning electron microscope (SEM) and
transmission electron microscopy (TEM). Various factors such as clay concentration, thermal history,
and shear history were employed to give rise to the changes of morphological and internal structures.
Effect of Sintering Atmosphere on the Microstructure of Hot-Pressed Al2O3/Cu Nanocomposites
Authors: Oh Sung Tag , Kang Kae Myung
Published: March 2009

Microstructure of hot-pressed Al2O3/Cu composites with a different temperature for
atmosphere switching from H2 to Ar has been studied. When the composite atmosphere was
switched at 1100°C it lead to a more homogeneous microstructure and the highest fracture strength
with smaller deviation than when the atmosphere was switched at 1450°C. The strong sensitivity to
atmosphere, especially the oxygen content in the atmosphere, was found to be responsible for
observed changes, based upon the interfacial phenomena related to the formation of CuAlO2
Anisotropic Deformation Behavior of the Oriented Nanostructure of a Semicrystalline Terblock Copolymer with Multi-Scale Orderings
Authors: Park Youn Jung , Park Cheol Min
Published: March 2009

A highly oriented nanostructure of poly(styrene)-b-(ethylene-alt-propylene)-b-(ethylene) (PS/PEP/PE) semicrystalline terblock copolymer was deformed under tensile loading. Roll casting process oriented the microdomains of the terpolymer. Hexagonally ordered PS cylinders subsequently guided the crystallization of the PE block occurring in between the PS cylinders, resulting in the molecular chain orientation of the PE blocks perpendicular to the PS cylinder axis. The structure change of the terblock copolymer under deformation was monitored using Simultaneous Wide Angle X-ray Scattering (WAXS) and Small Angle X-ray Scattering (SAXS). The samples with the load parallel and perpendicular to the cylindrical axis of the PS show their mechanical failures at the strain of approximate 100 % and 210%, respectively. The anisotropic mechanical behavior was interpreted by interplay of the different types of the nano scale domains
Durability in Antimicrobial Effects of Silver Doped Hydroxyapatite Depending on the Synthesis Route
Authors: Oh Kyung Sik , Park Sang Hoon , Jeong Young Keun
Published: March 2009

Ag doped Hydroxyapatites (Ag-HAp) was prepared through either ion exchange or
coprecipitation to compare the durability of antimicrobial effect. In case of ion exchanged Ag-HAp,
the microbials reproliferated after 100 h, in spite of the rapid reduction of E.Coli during the initial
moment. On the contrary, coprecipitated Ag-HAp effectively suppressed the reproliferation until
1000 h. The difference in durability depending on synthesis route was analysed with respect to the
amount of silver released at each interval. In case of ion exchanged Ag-HAp, more than 60% of
overall silver was released during initial 10 minitues. On the contrary, coprecipitated Ag-HAp
released less than 40% of overall silver during the same period, meaning the comparatively uniform
release behavior.
A Study on Anodic TiO2 Photocatalyst for Water Purification
Authors: Oh H.J. , Lee J.H. , Jeong Y. , Suh Su Jeong , Chi C.-S.
Published: March 2009

The microstructure and photocatalytic characteristics of anodic TiO2 film have been investigated for applications in waste water treatment. The major structure of the fabricated anodic TiO2 film consisted of porous cell structure, of which the main crystal structure bas been found to be anatase type. The photocatalytic efficiencies of anodized TiO2 were evaluated by the degradation rate of aniline blue and the chemical states of anodic film were estimated by P2P spectrum. The reaction order and the rate constant for degradation of dye have been determined to be first dimension and 1.608410-4s. Due to the high bonding strength between TiO2 film, and the substrate and the high specific surface area, the anodized TiO2 can be used as efficient photocatalyst with high reactivity for waste water treatment and water purification.
A New Control Algorithm for Impressed Current Cathodic Protection on the Underwater Hull
Authors: Oh Jin Seok , Lee Myung Hyun , Kim J.D. , Lee J.Y.
Published: March 2009

Cathodic protection is a system of preventing corrosion by forcing all surfaces of a hull to be cathode by providing external anodes. A metal can be made cathodic by electrically connecting it to a more anodic metal within the electrolyte. Anodes of these metals corrodepreferentially, the corrosion current of the anode achieving cathodic protection of the underwater hull to which they are connected. This paper presents a new current control algorithm for ICCP (Impressed Current Cathodic Protection) system. The anode of ICCP system is controlled by an external DC source with converter. The function of anode is to conduct the protective current into seawater. The DC source is generally obtained from main power system that contains a transformer, converter and etc. The proposed algorithm can operate AC-DC converter with current link. This algorithm includes the harmonic suppression control strategy and the optimum protection strategy and has tried to test the
requirement current density for protection, the influence of voltage, the protection potential. Also, the properties of ICCP protected hull of ship in seawater are evaluated.
Microstructure at/around Interface between Plasma-Sprayed Hydroxyapatite and Ti Alloy
Authors: Kobayashi Sengo , Kitashita Kotaro , Nakai Kiyomichi , Kuwano Noriyuki
Published: March 2009

Microstructures of the interface between plasma-spray coated hydroxyapatite (HAp) and
Ti-alloy substrate have been investigated mainly by means of transmission electron microscopy. The
results obtained are as follows; HAp coating exhibits a high crystallinity. The interface of
HAp/Ti-alloy is winding at an interval of about 100µm and thickness of HAp coating is about 50µm.
Al2O3 abrasives remained in both HAp coating and Ti-alloy substrate around the interface.
Amorphous phase was not observed at the interface. The grain size of Ti-alloy in the vicinity of the
interface is about 10 to 100nm in diameter, while that far from the interface is about 3µm in diameter.
Miniaturization of Ti-alloy grain around the interface was occurred by plasma spraying. There is no
specific crystallographical orientation relationship between HAp and Ti-alloy at the interface,
indicating bonding of the interface is essentially mechanical one such as an anchor effect.
Thermodynamic Analysis of Thermoelastic Martensitic Transformations
Authors: Liu Yinong
Published: March 2009

This paper is concerned with the application of fundamental thermodynamic theories in
the analysis of thermoelastic martensitic transformations in shape memory alloys, with a particular
reference to polycrystalline NiTi. The discussion is delivered in two parts. The first part presents a
concise overview of the fundamental theories of thermodynamics of thermoelastic martensitic
transformations established in the past 30 years. The second part focuses on the principles
governing the application of the theories, interpretation of the thermodynamic parameters defined in
the theories, experimental determination of the parameters, and some common misperceptions and
unjustified assumptions in practice concerning these parameters.
Development of Light-Weight Al Scroll Compressor for Car Air Conditioner
Authors: Park Ik Min , Choi Il Dong , Park Yong Ho
Published: March 2009

The scroll compressor with high cooling efficiency and lower oscillating noise can be a candidate material for a part of car air conditioner, household air conditioner and so on. When Al alloy with high strength is used for scroll compressor instead of cast iron, rotation speed can be increased by weight reduction. To design Al alloy which has enough mechanical properties to replace cast iron, the effect of alloying elements, such as Si(13-15%), Cu(4-5%), and Mg(0.5-1%) and cooling rates on the mechanical properties of squeeze cast Al alloy was studied. The influence of Sr and P modification treatment on Si morphology was also studied. Aluminum alloy over 400MPa of tensile strength and 2% elongation was developed. Al scroll samples was fabricated by squeeze casting machine(UBE 800ton) with using 2 cavity mold. Flow-3D which is a three dimensional melt flow analysis program was used to find most proper mold design and optimum process conditions for squeeze casting before making samples. Relationship between secondary dendrite arm spacing and cooling rate was simulated by Flow-3D and compared with experimental results.
Effect of Bubbling on the Primary Silicon in Hypereutectic Al-Si Alloy
Authors: Choi Jung Pyung , Lee Sang J. , Yoon Eui Pak , Yoon W.Y. , Kim M.H. , Kim K.H.
Published: March 2009

This paper investigates the effect of bubble on the primary Si size in Al-18wt.%Si alloy. The primary Si size observed was varied with bubble size and bubbling time in bubble process. The effect of the holding temperature of the melt in bubbling process was also investigated. In water model, as the injecting bubble size decreases, the residual bubble size in the water decreases and the residual bubble conservation time in the water increases. Also in the experiment of Al melt, the primary Si size decreases, as the injecting bubble size decreases and as the bubble processing time increases. Pore was observed at the center of primary Si. This pore was observed at many Si phases. So, this experiment suggests that the bubble can be used as nucleation sites of primary Si.
Effect of Distribution Coefficient on Copper Purification by Zone Refining Process
Authors: Yoon Young Ok , Jo Hyung Ho , Cho Hoon , Kim Shae K. , Kim Young Jig
Published: March 2009

It has been generally known that the refining efficiency in zone refining process depends on travel rate, number of pass and distribution coefficient of impurity. In the present study, the effect of distribution coefficient on copper purification was investigated by zone refining process. A numerical model capable of predicting the solute redistribution at any stage of zone refining was proposed. The composition profiles of each segment at the given condition were compared with the results of micro hardness profiles. After zone refining, metallic elements were analyzed by GDOS (Glow Discharge Optical Spectroscopy) and GDMS (Glow Discharge Mass Spectrometry).
The impurities Ag, Pb, S and Ti, whose distribution coefficients are below 0.5, were concentrated at the finishing position. Cr, Mn, Si and Zn, whose distribution coefficients are between 0.5 and 1, were distributed irregularly. Fe and Ni, whose distribution coefficients are greater than 1, moved to the starting position. It was found that zone refining process was actually effective to remove impurities whose distribution coefficients are below 0.5. The experimental results agreed well with the simulation result.
Dissimilar Joining of Nickel Aluminide Intermetallic Compound with Spheroidal Graphite Cast Iron by Using Combustion Synthesis
Authors: Kimata T. , Uenishi Keisuke , Ikenaga Akira , Kobayashi Kojiro F.
Published: March 2009

Nickel aluminide based intermetallic compounds were combustion synthesized
from a powder mixture of elemental Al, Ni, and Si and were simultaneously bonded with spheroidal graphite cast iron substrate (FCD). Addition of Si to the elemental mixture of Al and Ni was confirmed to be effective both to the densification of combustion synthesized intermetallic compounds and to the joining between compounds and FCD. When the composition of precursor
was Ni-69at%Al-9at%Si (Al/Si is the ratio of the eutectic composition), Al3Ni and Al6Ni3Si were mainly combustion synthesized. In the interface between compounds and FCD, reaction layers were formed to the thickness of 10 µm and the constituent phases were identified as Al7Fe2Si, FeAl3 respectively.
In the four point bending test of the dissimilar joints prepared by heating at 973 K for 300 s, the brittle fracture did not occurred around the joint interface but mainly in the inside of nickel aluminide coating. The interface of reaction layers with 10 µm were chemically well bonded. The sample with Ni-69at%Al-9at%Si coating exhibited highest bonding strength of about 56 MPa because of the smallest void ratio of the obtained compounds.
Preparation and Characterization of Porous Si-Coated SiC Fiber Media
Authors: Yu Jun Suh , Lee B.S. , Choi Sung Churl , Oh Ji Hun , Lee Jae Chun
Published: March 2009

Electrically conductive porous Si/SiC fiber media were prepared by infiltration of liquid
silicon into porous carbon fiber preforms. The series rule of mixture for the effective electrical conductivity was applied to the disc shaped samples to estimate their silicon content, effective electrical conductivity and porosity. The electrical conductivity was estimated by assuming the disc sample as a plate of equivalent geometry, i.e., same thickness, electrode distance and volume. As
the volumetric content of silicon in a sample increases from 0.026% to 0.97%, the estimated electrical conductivity increases from 0.17 S/cm to 2.09 S/cm. The porosity of the samples measured by Archimedes principle was in the range of 75~83% and 1~4% less than the one estimated by the series rule of mixture for the effective electrical conductivity.
Synthesis and Evaluations of Microstructure Properties on Al-(50, 60, 70 mass%)Si Systems by Mechanical Alloying
Authors: Lee Jung Il , Hong Tae Whan , Kim Il Ho , Ur Soon Chul , Lee Young Geun , Ryu Sung Lim
Published: March 2009

High silicon Al-Si alloy powders having nanocrystalline structures have been produced by mechanical alloying process. Microstructures in mechanically alloyed Al-Si powders were investigated by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses were also carried out to characterize lattice constant, crystallite size and misfit strain. Effective milling time for the formation of nanocrystalline microstructure was thought to be approximately 12 hours, and the sizes of Al and Si crystallites in mechanically alloyed powders after
longer than 12 hours of milling were reduced to about 30nm and 70nm respectively, in Al-70 mass% Si alloy system. The misfit strains increased with milling time up to 240 hours, and saturated to 5.73×10-3 and 4.39×10-3 for Al and Si crystallites, respectively.
Sintering Distortion of Barrier Ribs Formed via Capillary Molding
Authors: Chang Tea-Jung , Yoon Sang Hoon , Kim Yong Seog
Published: March 2009

Various closed-cells of plasma display panel were prepared via capillary moldingof paste containing ceramic powders of barrier ribs. The cells include meander, honeycomb, waffle and SDR. In this study, the sintering behaviors of such barrier ribs were investigated. The effects of pre-firing temperature, solid content in the paste, and type of cells on morphologies of the ribs were examined. The results indicated that cells with asymmetric geometry such as SDR and meander results in severe distortion after the sintering. The cells with symmetric geometry such as waffle and honeycomb, on the other hand, the distortion was negligible. Using the waffle type cells, the luminance characteristics of PDP device were evaluated.