bluuebunny/crossref_metadata_2025 huggingface dataset:
DEVELOPMENT OF PAVING MATERIAL FOR FOOTPATH AND CAR PARK PAVEMENT USING GRANITE SOIL
Authors: NAGAMACHI MASAHARU , MIZUGUCHI HIROYUKI , INOUE KENTARO , KAMADA KOICHI
Published: November 2006

It is required to develop new paving materials for pavements, such as footpaths, car parks, etc., in parks, having good landscape. Such paving materials have been already developed, but these do not have sufficient strength, abrasion resistance and frost resistance.

In this study, a new paving was examined material using cement, sand and granite soil. The mix proportion of this material tested was 2:4:4 of cement, sand and granite soil by mass. The maximum flexural and compressive strength were both obtained at a water content of 14% of the total mass, and the strength were several times larger than that of paving material on the market consisting of 10% of cement and 90% granite soil. The abrasion resistance was tested according to ASTM C 779, and this resistance was about four times greater than that of the paving material on the market.

The frost resistance was obtained high value compared with the concrete of 72% in water cement ratio by a new simple resisting test method for freezing and thawing using liquid nitrogen and warm water. It is considered that this new paving material is applicable to pavement for footpath, car park, etc.
INFLUENCE OF Cl- DEPOSITION CONTENT ON CORROSION OF LY12
Authors: HAN DESHENG , LI DI , ZHENG TIANLIANG
Published: November 2006

A series of accelerated corrosion tests were conducted in the simulated marine atmosphere environment to study the corrosion of LY12 aluminum alloy under different Cl - deposition content. The change of corrosion morphology, weight gain and electrochemical parameters (Corrosion Electric Potential, AC Impedance) were inspected in the corrosion course. The different corrosion behaviors caused by the variation of Cl - deposition content were also discussed.
ELECTROMECHANICAL BEHAVIOR OF CARBON NANOTUBES-CONDUCTING POLYMER FILMS
Authors: KIM CHEOL , LIU XINYUN
Published: November 2006

A relationship between strain and applied potential is derived for composite films consisting of single-wall carbon nanotubes (SWNTs) and conductive polymers (CPs). When it is derived, an electrochemical ionic approach is utilized to formulate the electromechanical actuation of the film actuator. This relationship can give us a direct understanding of actuation of the nanoactuator. The results show that the well-aligned SWNTs composite actuator can give good actuation responses and high actuating forces available. The actuation is found to be affected by both SWNTs and CPs components and the actuation of SWNTs component has two kinds of influences on that of the CPs component: reinforcement at the positive voltage and abatement at the negative voltage. Optimizations of SWNTs-CPs composite actuator may be achieved by using well-aligned nanotubes as well as choosing suitable electrolyte and an input voltage range.
A SMART POLYMER COMPOSITE ACTUATOR WITH THIN SMA STRIPS
Authors: KIM CHEOL
Published: November 2006

The characteristics of SMA to provide a high force and a large strain make them a good candidate for an actuator for controlling the shape of smart structures. Using a mathematical model that captures the thermo-mechanical behaviors and 2-way shape memory effect (TWSME) of SMA, some smart shell structures were analyzed numerically and experimentally. The deflections of morphing shells to that thin SMA strips are attached were investigated depending on various phase transformation temperatures. SMA strips start to transform from the martensitic into the austenitic state upon actuation through resistive heating, simultaneously recover the prestrain, and thus cause the shell structures to deform three dimensionally. The behaviors of composite shells with SMA strips were analyzed using FEM and 3-D constitutive equations of SMA. Several morphing composite shell structures were fabricated and their experimental shape changes depending on temperatures were compared to the numerical results. That two results show good correlations indicates FEA and 3-D constitutive equations are accurate enough to utilize them for the design of smart shell structures for various applications.
DEVELOPMENT OF AN OPTICAL MEASURING SYSTEM FOR GEOMETRIC ERRORS OF A MINIATURIZED MACHINE TOOL
Authors: KWEON SUNG-HWAN , LIU YU , LEE JAE-HA , KIM YOUNG-SUK , YANG SEUNG-HAN
Published: November 2006

Recently, miniaturized machine tools (mMT) have become a promising micro/meso-mechanical manufacturing technique to overcome the material limitation and produce complex 3D meso-scale components with higher accuracy. To achieve sub-micron accuracy, geometric errors of a miniaturized machine tool should be identified and compensated. An optic multi-degree-of-freedom (DOF) measuring system, composed of one laser diode, two beam splitters and three position sensing detectors (PSDs), is proposed for simultaneous measurement of horizontal straightness, vertical straightness, pitch, yaw and roll errors along a moving axis of mMT. Homogeneous transformation matrix (HTM) is used to derive the relationship between the readings of PSDs and geometric errors, and an error estimation algorithm is presented to calculate the geometric errors. Simulation is carried out to prove the estimation accuracy of this algorithm. In theory, the measurement resolution of this proposed system can reach up to 0.03 μm and 0.06 arcsec for translational and rotational errors, respectively.
ULTRASONIC CHARACTERIZATION OF CARBON/CARBON COMPOSITES BASED ON A PEAK-DELAY MEASUREMENT METHOD
Authors: YANG IN-YOUNG , LEE KIL-SUNG , IM KWANG-HEE , HSU DAVID K. , SONG SUNG-JIN , CHO HYEON , PARK JE-WOONG
Published: November 2006

In this work, a C/C composite material was nondestructively characterized and a technique was developed to measure ultrasonic velocity in C/C composites using automated data acquisition software. We have proposed a peak-delay measurement method based on the pulse overlap measurement method. Also through transmission mode was performed to compare ultrasonic velocity with the above peak-delay measurement method in an immersion tank. The variation of ultrasonic velocity was measured and found to be consistent with those in a large C/C composite. These results were compared with that obtained by dry-coupling ultrasonics. For mapping out the material property inhomogeneity, through-transmission scans were used based on both amplitude and time-of-flight of the ultrasonic pulse. A peak-delay measurement method well corresponded to the ultrasonic velocities of the pulse overlap method and through-transmission mode and C -scan image signal.
DYNAMIC DEFORMATION BEHAVIOR OF SOFT MATERIAL USING SHPB TECHNIQUE AND PULSE SHAPER
Authors: LEE OUK SUB , CHO KYU SANG , KIM SUNG HYUN , HAN YONG HWAN
Published: November 2006

This paper presents a modified Split Hopkinson Pressure Bar (SHPB) technique to obtain compressive stress strain data for NBR rubber materials. An experimental technique with a modified the conventional SHPB has been developed for measuring the compressive stress strain responses of materials with low mechanical impedance and low compressive strengths, such as the rubber and the polymeric material. This paper uses an aluminum pressure bar to achieve a closer impedance match between the pressure bar and the specimen materials. In addition, a pulse shaper is utilized to lengthen the rising time of the incident pulse to ensure dynamic stress equilibrium and homogeneous deformation of NBR rubber materials. It is found that the modified technique can determine the dynamic deformation behavior of rubbers more accurately.
MECHANICAL BEHAVIOR OF FREESTANDING Mo THIN FILMS FOR RF–MEMS DEVICES
Authors: KIM JAE-HYUN , LEE HAK-JOO , HAN SEUNG-WOO , KIM JUNG-YUP , KIM JUNG-SIL , KANG JAE-YOON , CHOA SUNG-HOON , LEE CHANG-SEUNG
Published: November 2006

Radio frequency microelectromechanical systems (RF–MEMS) are an attractive solution for wireless telecommunication applications. Freestanding films play an important role in RF–MEMS devices. For the successful commercialization of RF–MEMS devices, however, it is necessary to evaluate the mechanical reliability of freestanding films. The first step in the evaluation is to characterize the mechanical behavior of the films. This study focuses on freestanding Mo thin films. Mo test structures with a thickness of 960 nm were fabricated using sputtering deposition and patterned using a surface and bulk micromachining process. The strip-bending test was used to measure the stress–strain relation of the freestanding Mo thin films. The measured elastic modulus, initial stress, and yield strength of Mo thin films are reported.
STABILITY ANALYSIS OF DUNNAGE FOR TRANSPORTATION OF A STEEL ROLL COIL
Authors: KWAC LEE-KU , KIM JAE-YEOL , KIM HANG-WOO , HAN JAE-HO , LEE YOUN-SIN
Published: November 2006

When ironwork, especially steel roll coil, is transported to customers, land transportation and sea transportation are usually used. To transport steel roll coil fast and safe without damaging it, it is necessary that the steel roll coil has to be in stable condition. These days, apitong, which is all imported from overseas, is being used to support the steel roll coil, but because of apitong's rigidity, it damages the coil and when the coil is damaged, it is hard to fix. Due to the fact that recovering damage of the coil is almost impossible, we have to find the new type of dunnage that can substitute the apitong. In this paper, the arrays and the kinds of reinforcements, and rectangular type and trapezoid of dunnage will be talked about. The phenomenon of rolling and the impact when the carrier start moving and stop will be talked about as well. Therefore, we are going to develop a dunnage that does not damage ironwork and has better recovery and softness than existing apitong dunnage.
A STUDY ON FATIGUE DAMAGE OF SHAPE MEMORY ALLOY COMPOSITE USING NDE TECHNIQUE
Authors: PARK YOUNG-CHUL , LEE JIN-KYUNG , LEE SANG-PILL , LEE GYU-CHANG , LEE JOON-HYUN , CHO YOUN-HO , LEE JONG-BACK
Published: November 2006

TiNi shape memory alloy was used to recover the shape of transformed objects using its shape memory effect. This shape memory effect plays an important role inside metal matrix composite. A composite using shape memory alloy has a large advantage that can control crack initiation and propagation, when compared with other composites due to the shape memory effect of shape memory alloy under high temperature. In this study, TiNi/Al6061 and TiNi/2024 shape memory composites were fabricated by the hot press method, and a fatigue test was performed to evaluate the fatigue damage for the shape memory composites under room temperature and high temperature. The relationship of the crack growth rate and the stress intensity factor for these shape memory composites were clarified at both temperature conditions. The delay effect of crack propagation due to shape memory alloy was also evaluated under high temperature. In addition, an acoustic emission technique was used to evaluate the crack initiation and the control of crack propagation by shape memory effect under fatigue test nondestructively. The relationship between AE parameter and the degree of fatigue damage of the shape memory composites was discussed.
EFFECTS OF THE MAXIMUM UNDEFORMED CHIP THICKNESS ON ROUGHNESS AND SPECIFIC ENERGY IN SURFACE GRINDING
Authors: LEE YOUNG MOON , BAE DAE WON , LEE HYUN GU
Published: November 2006

In this study, effects of the maximum undeformed chip thickness on roughness of ground surface and specific grinding energy were investigated. The acoustic emission (AE) signals generated during grinding processes have been analyzed to find out the appropriate AE parameters for assessing the processes. SM45C steels were ground under conditions yielding volumetric removal rate per unit width of 100, 200, 300 and 400 mm3/min. From the experimental results, it is found that surface roughness ( Ra ) increases but grinding power (P), energy rate of AE signal (AErms2) and specific grinding energy(e) consumed decrease as the maximum undeformed chip thickness(g) increases.
PREDICTION OF THE FATIGUE STRENGTH OF NODULAR CAST IRONS UNDER COMBINED LOADING
Authors: ENDO M. , ISEDA K.
Published: November 2006

A criterion was proposed for the prediction of the multiaxial fatigue strength of specimens containing small holes. The criterion was applied to nodular cast irons containing graphite nodules and small casting defects such as microshrinkage cavities. Combined axial and torsional fatigue tests were carried out to examine the influences of torsional shear stress amplitude, axial normal stress amplitude, the ratio of these stress amplitudes, phase difference, and mean stress. The materials investigated were nodular cast irons with a ferrite matrix, JIS FCD400, and a pearlite matrix, JIS FCD700. A method for the prediction of the lower bound of fatigue strength was presented. Reasonable agreement between predictions and experimental results was obtained.
AN ANALYSIS OF MODE I FATIGUE CRACK GROWTH UNDER BIAXIAL STRESS
Authors: ENDO M. , SAKAI H. , MCEVILY A. J.
Published: November 2006

A modified linear-elastic method of analysis was proposed for the estimation of fatigue lifetimes of biaxially loaded components containing cracks. A constitutive relation of the crack growth rate, d a/ d N, was used as a basis for the analysis. The modifications included a correction for elastic-plastic behavior, consideration of Kitagawa effect, and consideration of the development of crack closure in the wake of a newly formed crack. A unified evaluation for the d a/ d N data measured by Brown and Miller in different biaxial stress states was made by use of the proposed method. It was found that the difference in elastic-plastic behavior accounted for the effect of biaxial stress on d a/ d N.
THERMAL STABILITY OF NANOCRYSTALLINE COPPER FILMS
Authors: CAO PENG , ZHANG DELIANG
Published: November 2006

The grain growth kinetics of nanocrystalline copper thin film samples was investigated. The grain size of nanocrystalline copper samples was determined from the broadening of X-ray spectra. It was found that the grain size increased linearly with isothermal annealing time within the first 10 minutes, beyond which power-law growth kinetics is applied. The activation energy for grain growth was determined by constructing an Arrhenius plot, which shows an activation energy of about 21 – 30 kJ/mol. The low activation energy is attributed to the second phase particle drag and the porosity drag, which act as the pinning force for grain growth in nanocrystalline copper.
FATIGUE PROPERTIES OF A T TYPE WELDED JOINT IN A SMALL-SIZED SINGLE PASS BOILER HEADER
Authors: YAMAKAWA H. , MURAKAMI R. , YONEKURA D. , LEE S. H. , YAN N.
Published: November 2006

The design of small-sized single pass boilers is usually based on the construction code for small-sized boilers, in Japan. Design methods in this construction code and other country codes have not been clearly defined, although most of small-sized boiler's headers are constructed from two concentric circular shells and cover plates. Therefore, Finite Element Analysis (FEA) with a PC and measurement by strain gauges are mainly used in strength design of these boilers. In this study, a T type welded joint of SS400 was adopted for the header of small-sized single pass boilers. Fatigue testing and FEA was carried out. The fatigue limit was greater for base metal than for weldment. For the weldment, the S - N curve decreased with decreasing ρ value. The stress concentration at the toe was evaluated by the FEA. S - N curves for different toe curvature radii were re-drawn using maximum elastic stress, Ktσmax. Crack initiation occurred in the vicinity of the toe. Several small cracks were observed on the surface of T type welded joint fatigue specimen at N/N f =0.42. These cracks coalesced together at a crack length of 10mm. Fatigue crack growth rate lineally increased with increasing (crack length)1/2.
POLYMERIZATION OF DIACETYLENE USING β-SHEET AS A TEMPLATE
Authors: MORI TAKESHI , FUKAWA YOICHI , SHIMOYAMA KENJI , MINAGAWA KEIJI , TANAKA MASAMI
Published: November 2006

In the parallel and anti-parallel β-sheet structures, hydrogen bonding arises between the amide bonds of the peptide chains to arrange them with a distance of ca. 5 Å. That distance matched with the repeating unit distance of polydiacetylene. In this study, the effectiveness of the β-sheet as a template for the polymerization of diacetylene was examined by using diacetylene-introduced oligopeptides. The diacetylene-introduced amino acid (Thr(DA)) was synthesized from L-threonine. Though peptides Ac-Thr(DA)-NHMe and Ac -[ Thr(DA) ]2- NHMe formed anti-parallel β-sheet, they showed slight or no polymerization in both of the solid and the solution states. On the other hand, Ac -[ Thr(DA) ]5- NHMe and 11mer peptide with a Thr(DA) in the center of the sequence contained anti-parallel β-sheet structure and formed polydiacetylene of high degree of polymerization with high conversion during the cleavage process of the peptide from resin in the solution. This result indicated that the preorganization of the peptide through the β-sheet formation was necessary for the polymerization of diacetylene group. Thus, the β-sheet motif was effective template for the polymerization of diacetylene.
EFFECT OF STORAGE TIME AND CONCENTRATION ON STRUCTURE OF REGENERATED SILK FIBROIN SOLUTION
Authors: XIE FANG , SHAO HUILI , HU XUECHAO
Published: November 2006

Concentrated regenerated silk fibroin (RSF) aqueous solutions with concentration close to that of the native silk fibroin (15.5%, 25.5% and 31%) were prepared. The effect of storage time and concentration on the conformational transition of the concentrated RSF aqueous solution was studied by Raman spectroscopy and circular dichroism (CD) spectroscopy. At the same time, the conformational change of RSF aqueous solution in flowing state was also investigated. It was found that the conformation of silk fibroin was changed gradually from random coil/α-helix to β-sheet structure during the storage. And the conformational transformation was accelerated with the increasing of the RSF aqueous solution concentration. When the solution was in flowing state, the conformational transformation was also accelerated.
STUDY OF ENVIRONMENTAL IMPACT BY COAL-FIRED POWER STATION
Authors: YOSHIZUMI KOJI , OGAKI MITUHARU , MOTONAKA JUNKO , YABUTANI TOMOKI
Published: November 2006

The Tachibana-wan coal-fired power station was constructed on land that was reclaimed using the soil that came from cutting through half of a small island while balancing the amount of soil. The power station has been generating for three years. When the electric utility provider projected the power station, it must have conducted an environmental impact assessment, and studied the environmental preservation measures. Moreover, after the power generation began, an environmental investigation was done as a follow up survey to study the environmental impact by the power station based on its construction and use. To study the environmental impact with smoke, the environmental density of sulfur dioxide around the power station was investigated. It fell below the environmental standards at all the environmental measurement points during this investigation. Moreover, a big difference was not seen before and after the beginning of the power generation and the change in these data was in the normal range. As a result of the environmental impact assessment, the contribution density of the power station was near the quantitative limit and a low value. To study the environmental impact with warm wastewater, the water temperature in the bay was investigated. A big difference was not generally seen before and after the beginning of the power generation though the water temperature slowly rose at the discharge point of the warm wastewater but the change of these data was in the normal range. As for the environmental impact, a clear judgment was difficult only from the environmental investigation. It is necessary to set a new environmental indicator to judge the environmental impact. Moreover, as for a new environmental assessment system, it is necessary to introduce a strategic environmental assessment.
EVALUATION OF MECHANICAL PROPERTIES OF CFRP BY VARTM AND ITS APPLICATION
Authors: KIM YUN-HAE , SON JIN-HO , CHOI BYUNG-KUN , JO YOUNG-DAE , KIM KUK-JIN , HAN JOONG-WON
Published: November 2006

In the present study, we contrast the change of mechanical and physical properties between VaRTM (Vacuum Assisted Resin Transfer Molding) and hand lay-up process. In the results of mechanical tests, VaRTM specimen is stronger than hand lay-up specimen and hand lay-up specimen became delamination. In the results of physical tests, the resin content of VaRTM specimen is lower than hand lay-up specimen. On micrograph, the strength of specimen by VaRTM between fiber and resin is stronger than that of one by hand lay-up. And the specimen by hand lay-up contains more defects than one by VaRTM. So, VaRTM process can practically apply for automobile engine hood. This paper shows that VaRTM process is one of the most suitable processes for composite parts of automobile.
EFFECTS OF Al, Ga-DOPING ON TRANSPARENT CONDUCTING PROPERTIES OF AMORPHOUS ZnO-SnO2 FILMS
Authors: MORIGA TOSHIHIRO , NISHIMURA YUSUKE , SUKETA HIROSHI , MURAI KEI-ICHIRO , NOGAMI KAZUHIRO , TOMINAGA KIKUO , NAKABAYASHI ICHIRO
Published: November 2006

ZnO SnO 2 thin films were deposited on glass substrates (Corning#1737) by DC magnetron sputtering. In this works, we examined a doping effect on a ZnO target on transparent conducting properties. ZnO:Al (4wt%), and ZnO:Ga (6wt%) targets were used for a dopant-free ZnO target. Substrate temperature was held at 250°C. The current ratio δ was defined as IZn/IZ + ISn ( ZnO target current divided by the sum of ZnO and SnO 2 target currents). Compositions of as-deposited films were changed with the current ratio δ. In the ZnO-SnO 2 system, amorphous transparent films appeared over the range of 0.33≤δ≤0.73. On the other hand, in the ZnO:Al (4 wt %)- SnO 2 and ZnO:Ga (6 wt %)- SnO 2 systems, they appeared over the range of 0.20≤δ≤0.80 and 0.33≤δ≤0.80, ≤δ≤ respectively. The minimum resistivity of amorphous films was about 3.0×10-2 Ω cm for all the systems. Al , Ga doping effect on film resistivity was not clear very much. But optical transparencies were 80-90% in visible region, 10% higher than those of ZnO-SnO 2 system at average. Optical band gap for the films with the same current ratio δ also was enhanced by the Al , Ga doping.
STUDY ON DYNAMIC FRACTURE CHARACTERISTICS AND APPLICATION TO THE STRUCTURES OF ADVANCED GLASS CERAMIC
Authors: KIM DUCK-HOI , KIM JAE-HOON , LEE YOUNG-SHIN , RHO NAM-SU , PARK CHUL-KYU , LEE GI-SEOK , MOON SOON-IL
Published: November 2006

In this study, the intrinsic static/dynamic fracture toughness of advanced glass ceramic is evaluated from the apparent static/dynamic fracture toughness of a notched specimen. A critical average stress fracture model is suggested to establish the relationship for predicting the intrinsic fracture toughness from the apparent fracture toughness of a notched specimen. The critical average stress fracture model is established using the relationship between the notch root radius and the effective distance calculated by finite element analysis. The effective distance is the major characteristic describing stress distributions ahead of the notch tip. Therefore, the effective distance can be used to evaluate the behavior of structures containing notches. It is concluded that the true fracture toughness can be estimated from test results of apparent fracture toughness measured by using a notched specimen. Also, the effective distance can be used to evaluate the failure criterion of structures with notches.
A STUDY ON THE TRIBOLOGY CHARACTERISTICS OF MoSi2 INTERMETALLIC COMPOUNDS UNDER DIFFERENT SINTERING TEMPERATURES
Authors: PARK WON JO , HUH SUN CHUL , LEE KANG YOUNG , SONG HONG TAE , YOON HAN KI
Published: November 2006

Molybdenum disilicide ( MoSi 2) is considered to be a promising high temperature material for turbojet and hypersonic engines in aerospace and various industrial applications, because of a high melting point (2030°C), adequate density (6.3g/cm3) and an excellent oxidation resistance. Some researches on MoSi 2 have been carried out but the wear behavior of this material is seldom studied. This paper focused on the effect of sintering temperature of MoSi 2 on the wear behavior. MoSi 2 powder was evaluated from the variation of fabricating conditions such as preparation temperature 1250°C, 1350°C and 1500°C. Wear tests were performed with a sliding speed of 5.21mm/sec and a normal load of 8kgf. Each test was run over a period of 6 hours. The wear behavior is evaluated with respect to the hardness of materials. Hardness test was carried out with a Micro-Vickers hardness tester. As a result of the tests, the friction coefficient was decreased with the increasing sintering temperature of MoSi 2 but the friction coefficient did not vary much for all specimens at temperatures. Hardness values decreased with a decrease in sintering temperature because the indentation under a lower temperature probably contained more defects.
TOTAL OXIDATION OF ACTIVATED CARBON OVER PdO-CeO2/TiO2-Al2O3 CATALYST
Authors: MURAI KEI-ICHIRO , MURAKAMI YUICHIRO , TOMOKO SEI , KATOH MASAHIRO , NAKABAYASHI ICHIRO , MORIGA TOSHIHIRO , TANAKA SUMINORI , KIDOGUCHI YOSHIYUKI , MIWA KEI
Published: November 2006

The work described in this paper is the oxidation reaction of activated carbon with NO 2 over PdO - CeO 2/ Al 2 O 3 catalysts. The starting temperature of carbon oxidation of NO 2 dropped to less than 150°C over PdO - CeO 2 catalyst. The effects of the addition of TiO 2 to PdO - CeO 2/ Al 2 O 3 catalysts on the oxidation reaction of activated carbon were also examined. The production of CO 2 at higher temperatures just after the beginning of carbon combustion (200~400°C) was enhanced by the catalyst containing equimolar TiO 2 to PdO catalyst.
DYNAMIC BEHAVIOR OF SINGLE-STAGE BELLOWS OF TITANIUM-NICKEL SHAPE MEMORY ALLOY UNDER CYCLIC LOADING
Authors: SEMBA HIROMASA , OKABE NAGATOSHI , YAMAJI TORU , OKITA KEISUKE , YAMAUCHI KIYOSHI
Published: November 2006

The dynamic behavior of TiNi shape memory alloy (SMA) bellows is examined in light of its potential use as elements in seismic protection devices. Dynamic property results obtained from cyclic tests under tension-compression loading of TiNi SMA single-stage bellows, with different shapes and with different heat treatments, are reported as a function of displacement amplitude and frequency. It was found that the displacement–force loops were almost symmetric with respect to the central point for almost all specimens. The normalized secant stiffness diminishes significantly with increasing bulge height as well as displacement amplitude. From hysteretic cycles, an equivalent damping of about 15% was recognized for longtime-aged bellows with relatively high bulge height. Frequencies, in the range of interest for seismic applications, had a small influence on damping values. Under the conditions studied in this research, the bellows had better damping performance in a martensite phase than in a rhombohedral phase. SMA bellows in martensite phase subjected to the longtime-ageing have great potential as an element in seismic devices.
ANALYSIS MODEL FOR SHAPE MEMORY EFFECT INTi-NiSYSTEM ALLOY OF RING CONFIGURATION
Authors: OKITA KEISUKE , OKABE NAGATOSHI , SATOH TOMOYUKI , UCHIDA KAZUNARI
Published: November 2006

Shape memory alloys are well known to be used as a ring element for connect coupling two pipes in various fields. In the case of structural and functional designs for a coupling ring of shape memory alloy, we have considered the shape memory effects in multi-axial stress and strain using volumetric strain in each element, so as to make FEM analysis more effective for optimizing the shape and the amount of pre-deformation. Using some uni-axial fundamental test results, as property parameters for FEM, the modeling method simulating the deformation behavior of a coupling ring has been eveloped in order to optimize the configuration and size of a coupling ring. The validity of this FEM modeling method was confirmed by verification experiments.
IN-SITU Cu-BASED BULK METALLIC GLASS COMPOSITES
Authors: WANG H. , FU H. M. , ZHANG H. F. , HU Z. Q.
Published: November 2006

Cu -based bulk metallic glasses are of relative low cost and high strength. They have more potential to be used as engineering materials. However, the lack of ductility has largely limited their applications. In the last few years, attempts have been made to form Cu -based BMG composites with two-phase microstructure to improve the ductility of BMGs, including extrinsic composites, in-situ composites and nanocrystalline composites. In this paper, two in-situ BMG composites have been successfully prepared with TiC and Ti 2 B particles respectively in-situ formed in the Cu -based BMG matrix. After the introduction of the TiC and Ti 2 B particles, besides of the lineal increase of hardness, the materials exhibit significant plasticity.
SYNTHESIS AND CHARACTERIZATION OF ALTERNATING COPOLYMERS CONTAINING CARBAZOLE AND ANILINE MOIETIES
Authors: WANG HUI , HAN DONG-HEE , CHANG SEUNG HYUN , RYU JEONG-TAK , KWON YOUNGHWAN
Published: November 2006

Four different types of alternating copolymers, named as poly(N-(2-ethylhexyl)-3,6-dibromo-carbazole-alt-aniline) (P1), poly(3,6-dibromo-carbazole-alt-aniline) (P2), poly(N-(3,5-dibromo-methylene-phenyl)-carbazole-alt-aniline) (P3) and poly(N-[4-(2-ethylhexyloxyl)-3,5-dibromomethylene-phenyl]-carbazole-alt-aniline) (P4) were successfully synthesized by palladium-catalyzed polycondensation of corresponding carbazole-containing dibrominated compounds and an aniline. These resulting polymers exhibited good solubility in normal organic solvents and showed relatively high molecular weights. Excellent thermal stability of the polymers was observed from TGA, showing less than 8% of weight loss on heating to 350°C under N 2 atmosphere. From UV-Vis absorption and photoluminescence spectra of these solution-processable polymers, it was observed that λ max,UV was in the range of 308 – 352 nm and λ max,PL was in the blue emission range of 450 – 463 nm. Electrochemical characteristics of these alternating copolymers were investigated to prove the potential in application for blue-emitting host matrix and hole-transporting layer in polymer light-emitting devices.
TERNARY ELECTRORHEOLOGICAL FLUIDS WITH COMPOSITE PARTICLES DISPERSED IN LIQUID BLENDS
Authors: MINAGAWA KEIJI , AOKI YASUNORI , MORI TAKESHI , TANAKA MASAMI
Published: November 2006

The electrorheological (ER) properties were studied with ternary suspensions containing solid and liquid dispersoids in silicone oil (DMS). The solid dispersoid used was polyether/montmorillonite nanocomposite particles in which polyether molecules were intercalated between the layers of montmorillonite. The liquid dispersoid was urethane-modified polyether prepared from 4,4′-diphenylmethane diisocyanate (MDI) and poly(propylene glycol) (PPG). The steady shear viscosity and dynamic viscoelasticity were measured with a rotating parallel disc rheometer equipped with ER measurement system. The binary and ternary mixtures of these solid and liquid dispersoids with DMS, i.e. composite particle/DMS suspension, polyether/DMS liquid blend, and ternary blend containing both dispersoids, showed an increase of viscosity in response to an electric field (positive ER effect). The ER effect of a ternary suspension containing the particles and polyether liquids was larger than those of binary suspension or blend with one of these dispersoids. The ER effect was found to be improved by combination of the solid and liquid dispersoids, although the recovery time of viscosity after removing the electric field became rather longer, which would be due to the partly irreversible macroscopic aggregation of the dispersoids.
PREPARATION OF ANTIMONY-PLATINUM SURFACE ALLOY ELECTRODE BY ATOM DIFFUSION IN THE SOLID PHASE
Authors: MATSUI HIROSHI , WATANABE KAZUFUMI
Published: November 2006

Antimony-platinum bilayers were prepared on titanium substrates by the two-step electrodeposition in the usual baths, and then surface alloys were formed by the atom diffusion in the solid phase. The simple antimony layer was little influenced by the substrate in both the measurements of X-ray diffraction and the i - E characteristic in a sulfuric acid solution. Regarding the bilayers, the catalytic activity in hydrogen evolution reaction was very sensitive to the presence of platinum, while the hydrogen adsorbability was quite insensitive. An interaction between antimony and platinum was confirmed by the appearance of a new dissolution wave in the electrochemical measurement and the occurrence of a new diffraction in the X-ray diffraction pattern after the heat-treatment of about 400°C. Although the new diffraction disagreed with any of the reported alloys, clear diffraction pattern of PtSb 2 alloy was observed, when the bilayers were heat-treated at about 600°C for one hour. Considering the penetration depth of X-ray, the alloying of antimony and platinum seems to occur also at low temperatures at least at the top surface.
CRYSTAL STRUCTURE EFFECT ON ELECTRICAL PROPERTIES OF YSZ CERAMICS
Authors: ZHANG CHUNXIA , GONG SHENGKAI , ZHOU CHUNGEN , XU HUIBIN
Published: November 2006

YSZ samples were prepared by Plasma Spray (PS) and Electron Beam Physical Vapor Deposition (EB-PVD) respectively. Microstructure and morphology were observed by SEM and XRD. Grain size of PS-YSZ was non-uniform caused by the inclusion of nano particle by molten particle and column crystal structure was observed for EB-PVD-YSZ. The Arrhenius plots of two samples were graphed by analysis of the measurement results of AC impedance spectra. The conductive mechanisms for EB-PVD and PS YSZ were different due to the crystal structure.
INFLUENCE OF ADDITION OF RARE EARTH ELEMENTS ON THERMAL BARRIER COATINGS MICRO STRUCTURAL EVOLUTION
Authors: JI XIAOJUAN , WEI QIULI , ZHOU CHUNGEN , GONG SHENGKAI , XU HUIBIN
Published: November 2006

Decreasing thermal diffusivity of YSZ can increase the thermal barrier effect. Thermal diffusivity is in direct proportion to lattice oscillation amplitude and frequency. The addition of rare earth oxide into YSZ may induce the lattice distortion, which will result in the change of lattice oscillation frequency. In the present work, combined with the experiment, a theoretical study was proposed to investigate the effect of the rare earth elements on the thermal barrier effect of YSZ using first-principal calculations implemented CASTEP program. It has been found that the addition of the rear earth element can make larger lattice distortion and favorable to reduce the thermal conductivity. The calculation results are in agreement with our experimental results.
BEHAVIORS OF CAS AND CUS THICK-WALLED CHANNEL COMPOSITE BEAMS
Authors: CHUN HEOUNG-JAE , PARK MI-JUNG , BYUN JOON-HYUNG
Published: November 2006

Recently the thick open section composite beams are extensively used to replace conventional metal load carrying members and stiffeners of structural elements. However, most of studies on the open section composite beams are confined to the thin composite beams. There are some works focused on the thick composite beams but they are limited only to closed section beams. Therefore, it is required to develop an appropriate model to analyze the thick open section composite beams. In this study, the cantilever beams of two specific lay-up configurations are considered which are the circumferentially asymmetric stiffness (CAS) and circumferentially uniform stiffness (CUS) beams. Under the vertical loading at the free end, loading induced deformations are obtained for the thick beams using the suggested model. The model includes coupled stiffness and secondary warping effects. The results are compared with those obtained using thin beam model to observe the thickness effects. Those results are also compared with the finite element analysis results for the verification of the suggested model. A good agreement is obtained between the results from the suggested model and those from finite element analysis.
A LONG PATHLENGTH SPECTROPHOTOMETRIC TEGAFUR DETECTOR USING A LIQUID-CORE WAVEGUIDE
Authors: WADA SHUJI , KAWATSU TOMOKI , HASHIZUME YUYA , YABUTANI TOMOKI , MOTONAKA JUNKO
Published: November 2006

A Liquid-Core Waveguide (LCW) detection system for high sensitive determination of tegaful (FT) was developed. In this system the LCW cell was connected to the end of a hollow cathode lump and the other end to a UV spectrometer. A sample solution containing FT was pumped to the LCW cell through a T-shaped connector. A UV absorption of analyte was detected by the UV spectrometer. The configuration of connectors of LCW cell to the light source and the UV detector was designed. Stable and high responses of FT were obtained in a double tube system in which an edge of LCW cell was covered with another tube with large diameter was set in the T-connector. It was found that the UV absorption response of FT obtained in this LCW system depends on the core length and the concentration of FT. The sensitivity of FT obtained by using 65 cm of the LCW cell length was 10-fold higher than that of using 1 cm cell which was often used with a conventional UV-visible detector.
A STUDY ON HYSTERETIC MODEL FOR WELD METAL AND ITS EFFECT ON BEHAVIOR OF STEEL PIPES WITH A WELDED JOINT
Authors: CHANG KYONG-HO , JANG GAB-CHUL , LEE SANG-HYONG
Published: November 2006

The weld metals used in welding process influences on behavior of steel structures under monotonic and cyclic loading. Because weld metals have different characteristics than structional steels for stress-strain relationship and mechanical properties. Therefore, to predict behavior of steel structure manufactured by welding process, a hysteretic model for weld metal is necessary. In this paper, to formulate the hysteretic model for E71T-1 weld metal, tensile tests and low cycle fatigue tests were carried out. A formulated hysteretic model applied to 3-dimensional elastic-plastic finite element analysis was proposed by the authors. To investigate the effect of weld metal on behavior of steel pipe members, numerical analyses of steel pipe with a welded joint were carried out under monotonic and cyclic loading. The effect of weld metal was clarified by comparing analytical results both steel pipe with consideration of weld metal and without consideration of weld metal.
INFLUENCE OF HEAT-TREATMENT ON WORKABILITY FOR ENLARGING PARTIAL DIAMETER OF CARBON STEEL SHAFT
Authors: ZHU XIA , OKABE NAGATOSHI , MORI KAZUKI , IURA TADASHI
Published: November 2006

A novel processing method to enlarge a partial diameter in the middle of shaft by means of combining a rotational-bending stress and an axial-compressive stress, can work various kinds of structural carbon steel without temperature-rise above 20K at room temperature. However, it was found that the maximum diameter-enlargement rate D f /D0 without initiating a fatigue damage crack decreased with increase in carbon contents of steel with mixed microstructure of ferrite and pearlite. It is thought that the mixed microstructure causes initiating the fatigue damage crack. In the present research, six kinds of heat-treatments of 823K-948K×5.4ks-tempering after 1153K×7.2ks-quenching were conducted for carbon steel shafts. The heat-treatments with change from mixed microstructure to uniform minute microstructures, are useful in increasing the diameter-enlargement rate [Formula: see text].
PROCESSING METHOD FOR ENLARGING PARTIAL DIAMETER OF STEEL SHAFT HEATED LOCALLY BY HIGH FREQUENCY INDUCTION
Authors: MORI KAZUKI , SUZUKI RISA , OKABE NAGATOSHI , ZHU XIA , IURA TADASHI
Published: November 2006

In the present works effective application of partial preheating by high frequency induction to enlarge the partial diameter of middle carbon steel was experimentally investigated. The partial reheating was carried out by varying preheating times under the same electric power conditions. As all other conditions other than temperature remained constant during the diameter enlargement experiments, the partial preheating effects were clarified to be estimative using a parameter of the σ/σ y , which was found to be dependent on temperature regardless of constant compressive axial stress. For heating times of less than 50 sec, the preheating effect for promoting partial diameter-enlargement did not appear. In fact the reverse effect appeared in times ranging from 30 sec to 50 sec due to blue brittleness generated at temperatures from about 523K to about 623K. Also, low cycle fatigue cracks must be avoided when initiating at the filet end of an enlarged shaft while passing through the temperature range of blue brittleness during the cooling process. Therefore, the preheating temperature found to be most effective for promoting the diameter enlargement was greater than about 856K so as to increase easily the D f /D0 to above 2 times without generating damage cracks from fatigue.
OPTIMIZATION TO MINIMIZE DEFLECTION OF A LARGE LCD GLASS PLATE WITH MULTI-SIMPLY SUPPORTS
Authors: LEE YOUNG-SHIN , LEE HYUN-SEUNG , CHOI YOUNG-JIN , BYUN SEONG-WOO , KIM WEOL-TAE
Published: November 2006

A LCD glass plate is supported by multi-pins and golf-tee type support. In the FEM analysis, the support condition is treated as a simply supported boundary condition. In this study, the optimization on the location of multi-simply support is conducted. The size optimization method of ANSYS 8.0 is used as the optimization tool to search for the optimal support location of LCD glass plate. In the manufacturing process, the support condition is a fatal factor of quality control of LCD production. From the results of optimization, deflection decreases 51% compared with the original model.
A STUDY ON THE THERMAL VIBRATION ANALYSIS OF THE GRAPHITE DISK UNDER THERMAL SHOCK
Authors: LEE YOUNG-SHIN , KIM JAE-HOON , KIM HYUN-SOO , KIM DUCK-HOI , KU SEONG-HOI , MOON SOON-IL
Published: November 2006

Graphite is applied to structural material of the high temperature reactor and nozzle of high energy rocket engine. The excessive vibration and stress field can be occurred for this material due to the severe thermal condition. In this study, the thermal stress and vibration characteristics of ATJ graphite under high temperature condition are investigated by finite element analysis (FEA). The specimen is designed as a disk shape in order to simulate the rocket nozzle combustion condition. The experiment of thermal heat is also conducted using by CO 2 laser.
THERMAL VIBRATION ANALYSIS OF RuO2 BY EXAFS
Authors: MURAI KEI-ICHIRO , AKUNE YASUHIRO , SUZUKI YOHEI , MORIGA TOSHIHIRO , NAKABAYASHI ICHIRO
Published: November 2006

Ruthenium dioxide which has a rutile-type structure is an important material in a viewpoint of electronic and magnetic properties. RuO 2 has a negative thermal expansion along c-axis in the high temperature region above room temperature. In this study, we could obtain detailed information about the thermal vibration of atoms by the analysis of EXAFS Debye-Waller factors. EXAFS analysis provides an effective pair potential with temperature dependent shape with Debye-Waller factor. The distance between second-nearest neighbor atoms ( Ru - Ru ) are equal to the length of c-axis in unit cell. It has become apparent that Ru - O bonds in RuO 6 octahedron are much stronger than the interaction between the second-nearest neighbor atoms ( Ru - Ru ) as same as FeF 2 in fluorides. Those results suggest that the negative thermal expansion along c-axis is caused by those weak interactions between second-nearest neighbor atoms ( Ru - Ru ).
EVALUATION OF THE HOOP TENSILE PROPERTIES OF A STEAM GENERATOR TUBE
Authors: CHO SUNG-KEUN , SEOK CHANG-SUNG , BAE BONG-KOOK , KOO JAE-MEAN
Published: November 2006

The steam generators in a pressurized water reactor (PWR) are large heat exchangers that use the heat from the primary reactor coolant to make steam on the secondary-side to drive turbine generators. Hoop stress is known to be the main cause of fracture of inner pressurized tubes such as the steam generator tube. However, because the steam generator tube is too small to be manufactured to a standard tensile specimen in the hoop direction, the axial tensile properties of the steam generator tube (or original material properties) instead of hoop tensile properties have been used to estimate the fracture properties of a steam generator tube. In this study, we have conducted not only axial tensile tests but also ring tensile tests. From these test, both the axial and hoop tensile properties of steam generator tubes were obtained, and the reliability of the hoop tensile properties were confirmed by burst test of a real steam generator tube.
THE MICROSTRUCTURAL ANALYSIS OF THE EFFECT OF FIC ON GAS TURBINE BLADES
Authors: KIM HYUNG-ICK , HUH YONG , PARK HONG-SUN , SEOK CHANG-SUNG , KIM MOON-YOUNG
Published: November 2006

Advancements in superalloys permit hot gas path components to operate for many thousands of hours under severe centrifugal, thermal and vibratory stresses. The blade of a gas turbine must withstand the most severe combination of temperature, stress, and environment. After a certain period of operation, the blade is damaged by the turbine operation mode. To recover the similar initial mechanical properties, the blade of nickel-based superalloy component undergoes a replacement repair process. A fluoride ion cleaning (FIC) process is used to assist in the successful welding repair of nickel-based superalloy components. This work is to study the FIC influence on a gas turbine blade that was serviced 25,748 equivalent operating hour (EOH) after first overhaul. The blades, including the fractured regions were obtained from a plant. The conditions of blade samples were observed by optical microscope and SEM, and the chemical composition of the flaws in the blade was investigated by EDS. γ′ phase morphology is also an important indicator of the mechanical properties of blades at the high temperatures. The blade condition was examined from morphology and size of the γ′ phase, because the γ′ phase coarsening rate depends largely on the exposure time and temperature.
FATIGUE CHARACTERISTICS OF SM490A WELDED JOINTS
Authors: HUH YONG , KIM HYUNG ICK , PARK JAE SIL , SEOK CHANG-SUNG
Published: November 2006

We compared the fatigue characteristics of weld metal with those of base metal heat-treated and non heat-treated. Also, we examined the influence of bead on fatigue life. From the experimental results of this study, it has been seen that the fatigue characteristics of welded specimens grinded the toe of bead are slightly better than those of welded specimens not grinded. Fatigue life is affected more by the stress concentration due to the profile change in the weld toe rather than by the residual stress, and heat-treatment had almost no influence on the fatigue characteristics.
CHARACTERIZATION OF BST PRODUCED BY HIGH TEMPERATURE HYDROTHERMAL SYNTHESIS
Authors: RAZAK K. A. , ASADOV A. , YOO J. , GAO W. , HODGSON M. , HAEMMERLE E.
Published: November 2006

Barium strontium titanate (BST) was produced in a teflon lined pressure vessel using a high temperature hydrothermal technique and controlling the processing parameters of Ba + Sr concentration, Ba and Sr ratio, temperature, reaction period and TiO 2 concentration. It was found that this technique produces BST powders of less than 200 nm particle size with high degree of crystallinity. However, most BST powders tend to be strontium rich. Thus, excess barium in the initial solution was essential in order to produce a high barium content in the final product, which was important to obtain good electrical properties. A high TiO 2 concentration was also crucial in producing BST with a high Ba content, though this parameter was responsible for a multiphase structure. The period of hydrothermal reaction was important for stoichiometric reaction.