巻号一覧
60 巻, 3 号
March
選択された号の論文の10件中1～10を表示しています
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研究論文
研究論文
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伊達 賢治, 安藤 慎輔, 川内 祐治, 立川 清2013 年 60 巻 3 号 p. 81-91
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスWe investigated the structure of the sintered porous metal for passive DMFC anode wick. This porous metal was made by space holder method and consists of large voids formed by space holder of the mean diameter 1000 µm (1000 µm SH) and the skeleton part with small voids formed by space holder of the mean diameter 180 µm (180 µm SH) and pores originated from the space among metal particles. The amount of penetrating fuel (10 mass% methanol solution) was proportional to the square root of immersion time. So, we connected the penetrating rate with the porous structure by “a bundle of capillaries" model based on Washburn equation by Bruil and Murata, et al. Penetrating rate became larger by the conditions below: (1) decreasing 1000 µm SH and increasing 180 µm SH to increase the skeleton part volume and its porosity, (2) increasing the fraction of smaller porosity of the skeleton part to increase its specific surface area, (3) coating metal surface with SiO2 to improve its wettability. But more than 75 vol% of 1000 µm SH was needed to release CO2 smoothly during generation. Additionally, 30 mass% methanol solution improved the generating performance without an effect of methanol crossover.抄録全体を表示PDF形式でダウンロード (2790K) -
木村 倫康, 橋本 英樹, 宮田 直幸, 仁科 勇太, 草野 圭弘, 池田 靖訓, 中西 真, 藤井 達生, Ivo SAFARIK, Mi ...2013 年 60 巻 3 号 p. 92-99
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスIn the natural aquatic environment, there are various types of biogenic manganese oxide (BMO) precipitates which are produced by manganese oxidizing microorganisms, at ambient temperature, atmosphere and neutral pH.BMO is a very interesting and useful functional material because of its unique property; hollow globule shape formed by nanosheets, large surface area and photocatalytic characteristics. In this study, thermally-processed BMO at 100 − 1000 °C was analyzed by XRD, XANES, SEM, TEM and nitrogen adsorption method to reveal the effects of heat-treatment on its crystal structure, Mn valence state, globule morphology, microstructure, pore size distribution and specific surface area. In the result, morphology of BMO is maintained below 800 °C, while nanosheets composing BMO were changed into nanoparticles at 600 °C. The crystal structure was transformed from birnessite into hausmannite (Mn3O4) at 600 °C. The specific surface area was increased by heat-treatment between 300 and 500 °C. In cases of artificial manganese oxides, such changes of crystal structure and specific surface area were not observed, and combustion of organic materials produced by microorganisms in BMO probably has a large effect on them.抄録全体を表示PDF形式でダウンロード (1807K)
特集：省エネルギーや環境負荷低減に寄与する磁石材料・磁性材料
総報
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松下 伸広2013 年 60 巻 3 号 p. 102-
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスPDF形式でダウンロード (105K)
受賞記念講演
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河野 健二, 八矢 正大, 飯島 洋祐2013 年 60 巻 3 号 p. 103-107
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスNiZn ferrite bulk materials have been fabricated using the conventional ceramic sintering method with a changing grain sizes from ～2.2 µm to ～13.5 µm. From the measurements of the complex permeability, it is suggested that the permeability is dominated only by the spin rotation at the mono-domain state and both domain wall motion and spin rotation contribute at the multi-domain state. At the mono-domain state, the core loss has been significantly decreased. The measurement result for the loss angle indicates that the low loss state can be maintained up to the higher magnetic field with the smaller grain size in spite of the mono-domain state. This study suggests the possibility of the magnetic coupling between the grains providing a new knowledge about the effect of the microstructure on the magnetic domain structure and the magnetization in NiZn ferrite.抄録全体を表示PDF形式でダウンロード (773K) -
徳岡 輝和, 伊志嶺 朝之, 前田 徹, 松沼 健二2013 年 60 巻 3 号 p. 108-116
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスRecently, there has been a growing trend toward reducing society's carbon footprint. In the field of energy, clean power generation systems, such as solar and wind generators, have been promoted. In the automotive industry, electric vehicles are also replacing petrol vehicles, and energy-saving electrical appliances are in demand more than ever. Due to this trend, small and powerful power-supply devices with better conversion efficiency are increasingly demanded, and accordingly, high performance inductors are strongly required. In this study, soft magnetic powder cores, which are made by compacting soft magnetic powder coated with insulating film, were successfully improved to be applied into such inductors. The advantageous properties of the developed material are reported, and evaluation results of applying them into inductors are also reported.抄録全体を表示PDF形式でダウンロード (1988K)
研究論文
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高田 幸生, 金子 裕治, 宮本 典孝, 平岡 基記2013 年 60 巻 3 号 p. 117-120
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスTo clarify the effect of Dy diffusing process for NdFeB magnets on their coercivity, the distribution and concentration of diffused Dy in a Nd2Fe14B grain were quantitatively image-analyzed. The case in which Dy diffused 10 % area from the surface of each Nd2Fe14B grain at the moderate temperatures shows the significant increase in coercivity of 7.5 kOe at 0.4 mass% Dy. In this case, Dy diffuses ordinally into grains from the surface toward the inside. On the contrary, in case of the excessive treatment such as 1000 °C, the expanding of the Dy-diffused area and also concentrating of Dy from the surface toward the inside of grains were simultaneously observed.抄録全体を表示PDF形式でダウンロード (729K) -
漁師 雄介, 中川 貴, 小林 義徳, 清野 智史, 山本 孝夫2013 年 60 巻 3 号 p. 121-127
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスThe effect of the particle size to magnetic properties of the SrZn2W - type ferrite (SrZn2Fe16O27) prepared by the Spark Plasma Sintering (SPS) method were investigated. SrZn2W - type ferrite powders with average particle sizesof 0.77, 0.54 and 0.45 µm were prepared by ball-milling for 3, 7, 10.5 hours. The SrZn2W - type ferrite powders were sintered by the SPS at 1073 − 1223 K for 0 − 30 min as holding time. The SEM observation showed that the domain size of the spark-plasma-sintered SrZn2W - type ferrite was maintained as the initial particle size. As the particle size became smaller, the spark-plasma-sintered SrZn2W - type ferrite showed larger coercivity. Compared to the SrZn2W - type ferrite prepared at 1523 K by the conventional solid reaction method, the spark-plasma-sintered ferrite had larger resonance magnetization and coercivity. These facts show that the SPS method is effective for the low-temperature sintering and improving the coercivity of the W type ferrite.抄録全体を表示PDF形式でダウンロード (2239K) -
北本 仁孝, 正木 貴章, 阿部 正紀, 上田 智章2013 年 60 巻 3 号 p. 128-131
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスThe present paper describes a magnetic-sensing device to detect superparamagnetic beads for a sentinel lymph node biopsy. The sentinel lymph node biopsy is a promising method to improve quality of life of patients after the surgery of the cancer. The sensing device consists of a solenoid coil to excite magnetically the beads and two Hall devices placed on the both ends of the coil. The differential signal between the two Hall devices reflects the existence of magnetic beads near one of the Hall devices. A computer simulation indicates that the signal increases with the increase of magnetic fields from the exciting coil. A prototype is designed based on the simulation of the devices that effectively detect the beads up to the distance of 10 mm from the sensor top. The sensing device detected superparamagnetic iron-oxide beads containing the Fe content of 0.5 mg, which are expected to accumulate in lymph nodes, at the distance of 8 mm; the estimated differential magnetic-field between the two Hall devices was 0.026 G.抄録全体を表示PDF形式でダウンロード (1025K)
本会記事
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2013 年 60 巻 3 号 p. Pref3_1-
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスPDF形式でダウンロード (100K) -
2013 年 60 巻 3 号 p. MtgPr3_2-MtgPr3_21
発行日: 2013/03/15
公開日: 2013/05/11
ジャーナル オープンアクセスPDF形式でダウンロード (586K)
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