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Kazuhiro SOGA, Shusuke YOMO, Zu-Gang LI, Pei-Herng HOR, Nobuo MÔ ...
1999 Volume 11 Issue 1 Pages
1-6
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The superconducting transition temperature (
TC), and the Hall coefficient (
RH) at room temperature (RT) and 77K were measured under hydrostatic pressure up to 1.2GPa for La
2CuO
4+δ system, where δ=0.015-0.108. Anomalous δ-dependence was observed in the
RH, which suggests a change in the electronic system. At 77K, there was little pressure effect in the
RH irrespective of δ-value. At RT, however, there was positive pressure dependence for the intermediate δ values between 0.060 and 0.080. The
TC of the 15K phase showed a negative pressure effect of -2 to -6K/GPa. The
TC of the 32K phase, however, showed a large positive pressure effect of 7 to 16K/GPa. The
TC of the 44K phase had a positive pressure effect.
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Tadaaki AMANO, Susumu ARAI, Yuko MAEKAWA, Masayuki KOBAYASHI, Akira HA ...
1999 Volume 11 Issue 1 Pages
7-13
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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High-temperature oxidation behavior of Fe-20Cr-4Al alloys with 3, 7, 35, 53, 104, 171, 185, 491, 1300 and 6300ppm of sulfur was studied for 18.0ks in oxygen at 1273, 1373, 1473, 1573 and 1673K by mass change measurements, observation of surface appearance of the alloys, X-ray diffraction, scanning electron microscopy and electron probe microanalysis. Mass change of the alloys increased roughly with increasing oxidation temperature. However, the mass changes of the alloys with 7, 35 and 53ppm of sulfur at 1473K, with 7, 35, 53 and 104ppm of sulfur at 1573K and with 7ppm of sulfur at 1673K showed negative values. This fact was in good agreement with spalling of the oxide on the alloys. On the other hand, mass changes of the alloys with more than 171ppm of sulfur decreased with increasing content of sulfur at 1673K. The oxide adherence of these alloys with more than 7ppm of sulfur may be attributed to the size and shape of chromium sulfide particles at the oxide/alloy interface.
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Takashi OKADA, Takanori NAKAMURA, Takanobu MATSUMURA, Yoshitake NISHI
1999 Volume 11 Issue 1 Pages
14-17
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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It is very important to evaluate the brittleness of Al
6Li
3Cu quasicrystal. Thus, we evaluate the brittleness of Al-Li-Cu quasicrystal alloy. The evaluated value of critical energy (E
f) is 5.6erg which value is smaller than cover glass and larger than Si wafer.
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Masakatsu TOMITA, Haruyuki KOJIMA, Suguru YAMADA, Atsumi KINOSHITA
1999 Volume 11 Issue 1 Pages
18-21
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The gels has lately attracted attention as functional materials of actuator, sensor and artifical muscle, etc. But their mechanical response and strength are still insufficient to apply these as functional materials. Hence, we synthesized gels with good response, and investigated their bending rates in electrolytic solutions by impressing electric field. We prepared Polyallylamine-metacryl acid, sodium salt gels (PAlAm-MAANa gels) from Allylamine phosphate, Methacrylic acid and N, N′-methylene-bis-acrylamide, and measured its bending rate in electrolytes solution under electric field. The result, the PAlAm-MAANa gels (PAlAm ratio; 50% and MBAA ratio; 7%) indicated bending rates of; 21.00°/s. Thus, the PAlAm-MAANa gels were found to be applicable to actuator and artifical musle as new functional materials.
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viscosity effect of the coolant
Naoya KATO, Katsumi DAIGO, Fujio SUDA
1999 Volume 11 Issue 1 Pages
22-25
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The granular-ice making method for cool-heat storage has been experimentally investiguted. Granular-ices were formed through injecting water droplets into a low temperature immiscible coolant whose specific gravity is smaller than water. As a low temperature immiscible coolant, kerosine or mixture of kerosine and engine oil has been utilized, where oil concentration was ranged from 0 to 40% in volume. It was found that the granular-ice can be successively produced even at -5°C. Above at -5°C, the ice-bridging phenomenon occurred for any concentration measured. Optimum conditions for succesive production of granular-ice were obtained as follows. 1) circulation of the mixture of kerosine and engine oil, and 2) no circulation of kerosine only. The effect of coolant temperature and viscosity on the successive production of granular-ices were discussed.
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Tadaaki AMANO, Masako SATO, Daisuke DOI, Masayuki HASHIMOTO, Akira OKU ...
1999 Volume 11 Issue 1 Pages
26-27
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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High-temperature oxidation of sintered Cr
2S
3 was studied for 18.0ks in oxygen at different temperatures from 773 to 1673K. Mass change of the Cr
2S
3 decreased with increasing temperature of oxidation and decreased gradually after oxidation at more than 973K. Identified oxide in the Cr
2S
3 was only Cr
2O
3. Amount of Cr
2O
3 increased with increasing temperature of oxidation.
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Takako KOHNO, Chikao UEMURA
1999 Volume 11 Issue 1 Pages
28-29
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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A CoSb
3 compound with a skutterudite structure (MX
3) is one of promising thermoelectric materials. In this study, the preparation of CoSb
3 thin films on glass substrates by the RF-magnetoron sputtering method has been researched. By using a Co-target and a Sb-target, simultaneous and alternate sputtering methods were carried out. Single phase CoSb
3 thin films have been successfully obtained under the following conditions; (1) annealing at 200°C in a vacuum after simultaneous sputtering, (2) annealing at 400°C in a vacuum after making multilayered Co/Sb/Co/Sb films by alternate sputtering.
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Kyoji TACHIKAWA, Seiichiro YAMAMOTO, Toshiyuki YOKOYAMA, Takaaki KATO, ...
1999 Volume 11 Issue 1 Pages
30-31
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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New (Nb, Ta)
3Sn conductors with excellent high-field performance have been fabricated using Ta-Sn powder as a core material. The Ta-Sn powder was easily synthesized by the melt diffusion reaction between Ta and Sn powders. The powder was encased in a Nb or Nb-Ta alloy sheath to form a composite, and then fabricated into wire and tape specimens. The resulting specimens were reacted at 800-925°C in vacuum. After the reaction a thick (Nb, Ta)
3Sn layer, several tens micrometers in thickness, is formed between the sheath and the core. No void is formed in the core after the reaction. Ta is incorporated into the (Nb, Ta)
3Sn layer from both the Ta-Sn core and the Nb-Ta sheath. The
Jc of the (Nb, Ta)
3Sn layer reaches 5×10
4A/cm
2 at 23T and 4.2K. The tape specimens show large critical current at 23T due to the large thickness of the (Nb, Ta)
3Sn layer.
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Tomonori OJIMA, Hiromasa YABE, Ryosuke KONDO, Hiroyuki IZUMI, Yoshitak ...
1999 Volume 11 Issue 1 Pages
32-33
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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We evaluate a permanent magnet by using a High-Tc (Y-Ba-Cu-O) superconductor. As results, it is an anti-magnetism permanent superconducting magnet, and we calculated saturation of magnetic density of 1.8kG by using Jhonson-Mehl equation.
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Takanori NAKAMURA, Takanobu MATSUMURA, Kazuo TAJIMA, Yasuyuki MIYAZAWA ...
1999 Volume 11 Issue 1 Pages
34-35
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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An actuator function using shape memory effect was studied for bi-ceramics glass. The reversible shape memory effect (SME) was found in the temperature range from 200 to 300°C. We conclude that the bi-ceramics glass is useful for creating a new type of actuators which can be operated within the medical micromachine in human body and corrosive environment.
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Takanobu MATSUMURA, Takanori NAKAMURA, Yasuyuki MIYAZAWA, Kazuo TAJIMA ...
1999 Volume 11 Issue 1 Pages
36-37
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Glass (plastic polymer) normally transforms to supercooled liquid (rubber) above the glass transition temperature (Tg). The transition causes the shape recovery effect. We have studied the shape recovery effect of SiO
2 glass. The shape recovery effect was found in the temperature range from 770K to 1170K. The SiO
2 glass can be a new actuator which can be operated at high temperature.
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Kazuhiro SHIGENOBU, Takanobu MATSUMURA, Ayumu YAZAWA, Yoshitake NISHI
1999 Volume 11 Issue 1 Pages
38-39
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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White radish sprout was used for the sample to study the effect of tourmaline on growth of plants. The samples with tourmaline-treated distilled water grew even more than that with ordinary distilled water. Furthermore, we discussed that the various tourmaline effects are induced if the tourmaline breaks up water cluster apart.
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Kenji SAKAMOTO, Takahiko OKUMURA, Hiroaki MATSUSHITA, Akinori KATSUI
1999 Volume 11 Issue 1 Pages
40-41
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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CuInSe
2 single crystals have been grown by synthesis solute diffusion method with controlling the growth rate. Effects of the Cu/In in solvents and the temperature of Se source on the purity of grown crystals have been studied. The single crystal with lower carrier density of -10
17cm
-3 was found to be grown from a stoichiometric solvent (Cu/In -1.0) when the temperature of Se source was 743K.
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Hiroshi YASUDA, Eisaku SEKIYA, Takashi MAEDA, Hiroaki MATSUSHITA, Akin ...
1999 Volume 11 Issue 1 Pages
42-43
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Among Cu-based compound semiconductors of Cu
3-Sb-VI
4 (VI=S, Se), Cu
2-IV-S
3 (IV=Ge, Sn) and Cu
2-Zn-IV-Se
4 (IV=Ge, Sn), single phases of Cu
3SbSe
4, Cu
2SnS
3, Cu
2ZnGeSe
4 and Cu
2ZnSnSe
4 were synthesized from respective melts, and single crystals of those four compounds were grown. Optical band gaps of Cu
2ZnGeSe
4 and Cu
2ZnSnSe
4 were determined by optical absorption measurements to be 1.64 and 1.40eV, respectively. From the temperature dependence of electrical resistivities, thermal band gap of Cu
3SbSe
4 was estimated to be 0.22eV.
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Atsushi TAKAHASHI, Moriaki WAKAKI, Muneo MIYASAKA
1999 Volume 11 Issue 1 Pages
44-45
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Parameters for the laser theraphy of hyperpigmented skin have not been established due to the difficulty to determine the optimum laser intensity. We tried to find out optimum irradiation conditions by using an acoustic shockwave generated at the laser treatment of a hyperpigmented skin. A skin model was fabricated to simulate the laser treatment of human skin.
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Yuichi KUSAKA, Kenji IKEDA
1999 Volume 11 Issue 1 Pages
46-47
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Photo-electric plethysmograph has been widely used to measure caradiac pulse rate. However, the sensing device is remained without any improvement, even though the opto-electronic technology has been highly refined recently. In order to get rid of low-temperature burn, which is often experienced in long-term, continuous applications, and to guarantee motion-free measurements, we develop a new type of photo-electric sensing device. The dcesign criteria and the merit of the prototype device are discussed in some detail.
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Ryo KAWAI, Manabu SAKAKIBARA
1999 Volume 11 Issue 1 Pages
48-49
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The pond snail
Lymnaea stagnalis is capable of learning the sequential event of light and rotation. Neural circuit, however, involved in this behavior has not been identified, we examined the relationship between photoreceptors and statocyst hair cells with the physiological and morphological techniques.
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Hiroyuki YONETA, Satoshi TAKEI, Kunki KUSAKAWA, Takahito KOUOU, Kiyoyu ...
1999 Volume 11 Issue 1 Pages
50-51
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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In order to analyze the autonomic functioning during sleep, all night polygraphic measurement including the pulse transit time (PTT) was carried out with healthy subjects under sleep deprived and natural sleep condition. Sleep stages were classified based on the EEG recordings. Average and standard deviation of the PTT were calculated in each segment. Effect of sleep deprivation on the autonomic function was investigated.
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Shuhei OGAWA, Toshihiko OHHASHI, Tatsuhiko SUZUKI, Nobuyuki SUZUKI, Ta ...
1999 Volume 11 Issue 1 Pages
52-53
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Relationships between MTS and sleep stage distribution were investigated. Polygraphic measurements were carried out with healthy subjects under sleep deprived and control condition. Results showed that relative frequency of sleep stage 2 and stage REM before the MTS period changed under sleep deprived condition compare with control condition.
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Kouji MIYAWAKI, Shinya ODAGAWA, Shihori AOKI, Yoshiaki HAYASAKA, Takah ...
1999 Volume 11 Issue 1 Pages
54
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The purpose of this study is to investigate the change of autonomic functioning induced by an emotionally stimulating game. In the game, subjects were asked to give words which can be classified designated category in limited time. The pulse transit time were measured and analyzed before, during and after the game. Characteristics of autonomic functioning in mentally cornered condition were discussed.
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Kazumi KAMATA, Katsurou OKAMOTO, Kiyoyuki YAMAZAKI
1999 Volume 11 Issue 1 Pages
55-56
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Artificially evoked somatosensory illusion was investigated. Using synchronized stimulation to the Phantom arm, duration of the illusion and positioning error were measured. Emotional effects of the cutter knife on illusionary sensation were discussed.
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Tatsuya HASEGAWA, Tatsuhiro KIMURA, Takahisa SANADA, Kiyoyuki YAMAZAKI ...
1999 Volume 11 Issue 1 Pages
57-58
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The purpose of this study is to investigate the visual process receiving the 3D stereographic pattern with conflicting figures. The visual stimulation induces two possible perceptions of 3D vision and binocular rivalry. Time feature of the dominance of two kind of vision was analyzed. The visual process in ambiguous situation was discussed.
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Yusuke MIYAMOTO, Sadao UEGUSA, Kenichiro NAKAMURA, Takanobu KUMAMOTO
1999 Volume 11 Issue 1 Pages
59-60
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Realistic molecular model was applied for characterizing the actual merocyanine-dye mixed L/LB film.
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Yukio NAGATA, Junichi MATSUSITA, Yuko INATOMI
1999 Volume 11 Issue 1 Pages
61-62
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Crystal growth processes of hen-egg-Lysozyme under high static magnetic field were studied by microscopic interferometry and dynamic light scattering measurements in order to control the crystallographic orientation. As a result, orientation of the crystals was obviously controlled by the direction of a magnetic induction under 6T, and few differences of the growth rates were observed from several nm to 400nm in the Lysozyme diameters under 0.6T.
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Tadaaki AMANO, Toshinori SUGIYAMA, Hiromichi MAENO, Teruhisa SAITO, Ta ...
1999 Volume 11 Issue 1 Pages
63-64
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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High-temperature oxidation of Fe-20Cr-4Al alloy purified by floating zone melting was studied for 18.0ks in oxygen at 1273, 1373, 1473, 1573 and 1673K. Mass changes of 0.99ppmS and 1.84ppmS alloys increased with increasing temperature of oxidation. On the other hand, mass change of 3.88ppmS alloy showed negative values after oxidation at 1473, 1573 and 1673K, because of spalling of oxide on the alloy.
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Tadaaki AMANO, Naoki SAKAI, Jun KAMEDA, Yasuhiro IWAZAKI, Akira HARA, ...
1999 Volume 11 Issue 1 Pages
65-66
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Oxidation of Fe-20Cr-4Al alloys with small amounts of sulfur and reactive elements was studied for 360ks in air at 1573K. Mass changes of the alloys with up to 185ppm of sulfur were 2.7-3.4×10
-2kg/m
2. Mass changes of the alloys with 1300 and 6300ppm of sulfur showed small values compared with the other alloys with sulfur. This result was in good agreement with spalling of oxide films on 1300 and 6300ppmS alloys. Mass changes of the alloys with sulfur and yttrium were 2.3-3.0×10
-2kg/m
2. On the other hand, mass changes of the alloys with sulfur and hafnium showed almost negative values because of marked spalling of oxide films on these alloys.
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Yoichi ISHIMOTO, Nozomi IMAHORI, Jun-ichi MATSUSHITA
1999 Volume 11 Issue 1 Pages
67-68
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Lead-zirconate-titanate (PZT) was prepared by a sol-gel process. As one process, lead acetate, zirconium tetra-
n-butoxide, and titanium tetra-
iso-propoxide were used as raw materials. 2-methoxyethanol and diethanolamine were used as solvents. As another process, lead acetate, zirconyl nitrate, and titanium tetra-
n-butoxide were used as raw materials. Distilled water, acetic acid, and tri-ethylene glycol were used as solvents. PZT were synthesized twelve ways on the basics to the two processes. Synthesized PZT by each had been dried for 24h at 338K. Dried samples had been sintered for 1h at 773K, 873K, and 1023K in air. The sintered samples were evaluated by X-ray analysis.
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Noriyuki FUKUSHIMA, Noriyuki TAKASHIMA, Jun-ichi MATSUSHITA
1999 Volume 11 Issue 1 Pages
69-70
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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In this study, CrSi
2 ceramics were prepared by hot-pressing. The influence of temperature on the electrical conductivity of CrSi
2 sintered body was investigated. The samples were sintered at 1273K to 1373K for 3.6ks in vacuum under a pressure of 40MPa. The relative density of sintered body at 1373K was approximately 99%. The high temperature electrical conductivity measured using a D. C. four-terminal method.
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Jun-ichi MATSUSHITA, Takahiro CHO, Akira TONEGAWA, Kazuo TAKAYAMA
1999 Volume 11 Issue 1 Pages
71-72
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The reactivity of fused silica glass (SiO
2) with plasma irradiation was investigated using argon gas sheet plasma in order to examine the suitability of this material for semiconductor and nuclear fusion application. The surface of the samples was evaluated using scanning electron microscope (SEM) and noncontactive three-dimensional roughness meter (ZYGO). Surface deterioration was observed by the plasma irradiation with decreased Ar gas flow rate. It was able to suppose this reason, the electron density in sheet plasma increased with decreasing Ar gas flow rate.
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Jun NAKAO, Kazuya OGURI, Yoshitake NISHI, Tsunenori SUZUKI
1999 Volume 11 Issue 1 Pages
73-74
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Titanium-aluminum alloys are favorable as superb light-weight and heat-resistant structure materials, and is also expected as structure material of a part of body of round-trip spaceships. We measured states of structures by investigating electric resistance and X-ray diffraction pattern. The hardness was measured in contrast with these results.
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Kazuaki MITSUGI, Hirokazu ISHII, Takasi OKADA, Yoshitake NISHI
1999 Volume 11 Issue 1 Pages
75-76
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Quasicrystal has some interesting properties due to its quasiperiodisity, which include higher hardness, higher electrical resistivity, and so on. We know that Al
5-Li
3-Cu has stable quasicrystalline phase. So, we investigated the formation of Al-Li-Cu quasicrystalline phase at various temperatures by making TTT curve. In this way, we could obtain the fundamental knowledge about the self-organization of the phase. The reason for the stability of the phase is discussed in terms of the quasicrystal growth kinetics.
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Ryosuke TOYOSHIMA, Hiromasa YABE, Yoji HIRAIWA, Kazuya OGURI, Yoshitak ...
1999 Volume 11 Issue 1 Pages
77-78
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Hardness of Zr-Al-Ni-Cu glass, which alloy is characterized by a smaller critical cooling rate, was measured in the heating process from RT to 773K. Along the increasing temperature up to 673K, the Vickers hardness decreased to one half of that at RT. At higher temperature, crystallization resulted in a drastically increased hardness.
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Ryosuke KONDO, Tomonori OJIMA, Kazuhiro SHIGENOBU, Yoshitake NISHI
1999 Volume 11 Issue 1 Pages
79-80
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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The collision energy generates the electrical potential of PZT. As the value of the energy increases, the electrical potential becomes higher. We often find the opposite electrical potential. Thus, we investigate the electrical potential. When the residual strain is relaxed enough, we can explain that the integrated electrical potential approaches to zero. This may induce the opposite potential.
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Hirokazu ISHII, Yoshitake NISHI
1999 Volume 11 Issue 1 Pages
81-82
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Image charge interaction reported by Ishii
et. al.1 at Cu/Y
2O
3-fully stabilized cubic ZrO
2 interfaces produced in the thermal evaporation method, was reproduced on a personal computer simply with classical electrodynamics. The difference in the interfacial adhesion force was observed between continuum/ZrO
2 (110) (a neutral plane) and continuum/ZrO
2 (001) (polarized plane) even if no quantum mechanical computation was done. Continuum/ZrO
2 (001) showed stronger adhesion force than that of continuum/ZrO
2 (001) at large interfacial interval. This result indicates that the image charge interaction works in a long range.
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Kuniaki TOMOMATSU, Jun-ichi MATSUSHITA
1999 Volume 11 Issue 1 Pages
83-84
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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In recent years, high temperature ceramics as materials with high strength and high melting point are drawing the attention for ceramists. These ceramic materials are expected to be used as a fireplace for nuclear fusion, aircraft engine, rocket nozzle and fireplace material for high temperature incinerator. High-temperature oxidation behavior of sintered Cr
3C
2 body was studied in air at 300-1400°C for 5min to 25h by measuring mass gain and X-ray diffraction. In spite of increasing temperature and time, weight gain by the oxidation of sintered Cr
3C
2 body was not approved at 1400°C. However, the oxidation was admitted by X-ray diffraction analysis at higher then 600°C.
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Nozomi IMAHORI, Yoichi ISHIMOTO, Tomomi NAGAO, Jun-ichi MATSUSHITA
1999 Volume 11 Issue 1 Pages
85-86
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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PLZT powder for ferroelectrics ceramics was prepared by a sol-gel method with lead acetate (Pb(C
2H
3O
2)
2). The crystallization of the sample could be controlled through the low heating process. Based on the results of the X-ray diffraction analysis, good crystallized PLZT peaks was observed of the sample heated at 850°C.
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Shinsuke KURIYAMA, Noriyuki TAKASHIMA, Jun-ichi MATSUSHITA
1999 Volume 11 Issue 1 Pages
87-88
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Carbide ceramics has various desirable properties, including such as a high melting point, a high hardness, the electrical conductivity, and chemical stability. In this study, Cr
3C
2 ceramics prepared by hot-pressing. The influence of temperature on the electrical conductivity of Cr
3C
2 sintered body was investigated.
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Takashi SATO, Junichi MATSUSHITA, Eiichi SATO, Kazuhiko KURIBAYASHI
1999 Volume 11 Issue 1 Pages
89-90
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) is common superplasticity ceramics and its deformation behavior at high temperatures is influenced strongly by trace impurities such as silica and alumina. Low purity materials more than 0.1% show only one region of stress exponent 2, while high purity materials show two deformation behavior region with stress exponent 2 at high stresses and 3 at low stresses. In the present study, another deformation region with stress exponent 1 at lower stresses is observed in high purity 3Y-TZP, by means of constant cross-head speed compression tests and constant load compression creep tests.
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Ryuhei TAKADA, Noritaka MARUYAMA, Kuniyasu GEMMA, Yoshihiro MURAGISHI, ...
1999 Volume 11 Issue 1 Pages
91-92
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Tensile strength of platinum alloys containing 5-20 mass% Rh were measured in temperature range of 300-873K. Both tensile strength and elongation decreased gradually with increasing temperature. The hardness was also measured using a micro hardness test, which decreased from HV103 at 373K to HV43 at 1273K. At the hardness of HV=50 and at the higher temperature, strongly increased brittleness was observed from the shape of indentation.
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Kei TANAKA, Kazuhiro TORIUMI, Tateki HAMADA, Kuniyasu GEMMA, Mamoru KA ...
1999 Volume 11 Issue 1 Pages
93-94
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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Various steels are prepared for a carburization in ferrite phase. Effect of alloying elements (Cr, Mo, V) for surface hardness was investigated in this study. The steel containing V and Mo increased the surface hardness to HV 550 approximately. No effect was obtained for the steels with only Cr and also with Cr and Mo.
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Hajime ONODA
1999 Volume 11 Issue 1 Pages
f1-f4
Published: August 15, 1999
Released on J-STAGE: February 25, 2010
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