著者
長谷 隆司 中山 武典 尾関 寿美男 坂西 敏之
出版者
公益社団法人 腐食防食学会
雑誌
Zairyo-to-Kankyo (ISSN:09170480)
巻号頁・発行日
vol.61, no.3, pp.93-97, 2012 (Released:2012-10-31)
参考文献数
11

超電導マグネットによる7.0 Tの磁束密度の磁場を印加することによって,通常の磁場を印加しない場合(NMT)に比べて,流動水中の普通鋼板のさびをより抑制できることが判明した.X線回折の定量分析結果は,さびの抑制に役立つと見られるアモルファスやナノサイズのさびの結晶の量の増加に,水の磁気処理(MT)が有効であることを支持している.NMTとMTの両方の場合で流動水が流れる配管の内部をモニタする実験を行って,MTの場合に配管内の鉄さびの付着をより抑制することがわかった.
著者
中山 武典
出版者
公益社団法人 腐食防食学会
雑誌
Zairyo-to-Kankyo (ISSN:09170480)
巻号頁・発行日
vol.64, no.7, pp.273-280, 2015-07-15 (Released:2016-01-22)
参考文献数
41
被引用文献数
4 4

回折,X線微細吸収構造法,イメージング,光電子分光法などとして利用可能な放射光は,従来のX線機器に比べて,高輝度で指向性に優れるなどの特長がある.このため,鋼材の大気腐食や耐候性鋼さびの生成と構造に及ぼす合金元素の影響,ニッケル上のPbのアンダーポテンシャル析出現象,ステンレス鋼の不動態皮膜の非破壊解析など,様々な金属腐食現象研究に適用されている.一方,回折,小角散乱法,イメージングなどとして利用可能な中性子線は,透過力が強く,水や水素の検出能が高いなどのユニークな特性を有している.これより,耐候性鋼さびの乾湿繰り返しにともなうさび粒子サイズや体積率の評価や塗膜下腐食鋼材のふくれ内部での水の動きの直接観察などの金属腐食現象の研究に応用されている.
著者
酒井 英男 小林 剛 泉 吉紀 中山 武 服部 克巳
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)
巻号頁・発行日
vol.136, no.5, pp.291-296, 2016

Study of the electric self-potential (SP) and the magnetic field was conducted at the explosion seismic experiment in Ooyama, Toyama Prefecture. The explosion was induced by 450 kg gun powder placed at a depth of 32.2-75 m. The SP was measured by four electrodes arranged in a line crossing the explosion point, where the distance of each electrode from the explosion ranged from 10 to 100 m. Induced SP changes consisted of two portions, namely, fluctuations with shorter periods (∼10 ms) and fluctuations with longer periods (∼50 ms). Regarding the latter, the amplitude was in proportion to the span length of electrode couples and the fluctuations arrived faster at the electrode couples nearer to the explosion. Further, the increment of ground level in SP was observed in each electrode couple after the explosion, which was concordant with the distribution of apparent resistivity underground studied by the survey. The magnetic field measured by the fluxgate magnetometer at the site 35 m north from the explosion also showed change of a few nT after the explosion. This may have been caused by change of magnetic properties underground.
著者
田中 秀和 中林 祐治 新居 正浩 石川 達雄 中山 武典
出版者
一般社団法人 粉体工学会
雑誌
粉体工学会誌 (ISSN:03866157)
巻号頁・発行日
vol.55, no.5, pp.269-274, 2018-05-10 (Released:2018-07-10)
参考文献数
29

In order to simulate the atmospheric corrosion of tannic acid-coated steels in industrial and coastal districts, artificial steel rust particles of α- and β-FeOOH were synthesized by aerial oxidation of aqueous Fe2+ solutions containing various amounts of tannic acid. Increasing addition amount of tannic acid accelerates the formation of amorphous iron-gallic acid complexes to suppress the generation of FeOOH rust. The crystallization and growth of α-FeOOH particles were inhibited by adding tannic acid, while those of β-FeOOH particles are markedly dependent of addition amount of tannic acid. Accordingly, it can be regarded that the tannic acid eluted from tannic acid-coated steels by atmospheric corrosion strongly affects on the formation of α- and β-FeOOH rust and the effect in coastal area is greater than urban district.
著者
酒井 英男 小林 剛 岡田 敏美 芳野 赳夫 早川 正士 富沢 一郎 中山 武 太田 健次
出版者
独立行政法人防災科学技術研究所
雑誌
防災科学技術研究所研究資料 (ISSN:0917057X)
巻号頁・発行日
vol.157, pp.287-317, 1993-03-29

Electromagnetic properties were measured at the joint observation of the explosion seismic experiment at Ooyama, Toyama Prefecture on Oct. 17, 1991. The explosion was induced by 450 kg gun powder placed at a depth of 75 m. This paper represents the preliminary results of the experiments. (1) Electric self-potential : The measurement of the electric self-potential (S.P.) was made at two stations. One station was set up around the explosion point, and the other station about 1.5 km apart from the explosion point. At the station about 1.5 km apart from the explosion area, we observed no distinct change in S.P. before the arrival of seismic wave. At the station around the explosion point, four electrodes were arranged in the line of east-west direction crossing the explosion point. The distance of the each electrode from the explosion point ranges from 10 m to 100 m. The seismograph sensor was arranged at the distance of 130 m for the comparion with the change of the S.P. Up to 150 mV changes in S.P. were observed by the electrode couples before the arrival of seismic wave. The detailed analsis revealed that the induced changes in the S.P. consist of two portions : the fluctuation with shorter period (〜0.001 second) and with the frequency of the longer period (〜0.05 second). The propagation speed of the fluctuation with the shorter period was much higher than that of the fluctuation with the longer period. The fluctuation of the shorter period might have been related to the explosion process of gun powder. About the fluctuation with the frequency of the longer period, the following properties were elucidated. The amplitude of the fluctuation in S.P. is in proportion to the span length of the electrode couples. The fluctuation in S.P. arrived faster at the electrode couples situated nearer to the explosion point. (2) Magnetic field The magnetic field was measured by the fluxgate magnetometer at the site 35m north from the explosion point. The apparentchanges of magnetic vertical component and of horizontal component were observed at the time of 0.25 seconds after the explosion. Increase of total magnetic field of 2〜3nT after the explosion was found. This increment was confirmed by the total magnetic field survey around the fluxgate sensor. (3) VLF electromagnetic radiation No clear radiation of VLF electromagnetic wave was seen because of the possible contamination of the other natural radio noises. However, a possibility of VLF radiation connot be denied. Further study of the VLF data should be carried out.
著者
中山 武典 田中 秀和
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.100, no.9, pp.1089-1096, 2014 (Released:2014-08-31)
参考文献数
106
被引用文献数
1 8

Progress of corrosion science and corrosion engineering of steels has been reviewed. Case histories of atmospheric corrosion including research and development of weathering steels, and environmental degradation such as stress corrosion cracking, hydrogen embrittlement and corrosion fatigue of steels were explained in detail. Finally, future subjects that should be done for better understanding of corrosion and corrosion control of steels were proposed.
著者
中山 武司 二宮 洋 浅井 秀樹
出版者
一般社団法人電子情報通信学会
雑誌
電子情報通信学会技術研究報告. CAS, 回路とシステム
巻号頁・発行日
vol.95, no.482, pp.31-38, 1996-01-25

タイリング問題とは有限の升目上に隙間なくポリオミノを敷き詰めていく典型的なNP-complete問題である. 本研究ではm×nの升目上に, 異なる形のι個のポリオミノを敷き詰めることを考える. はじめに, 我々が以前提案した接触検出関数を用いたタイリングアルゴリズムについてぶれる. 次に, その手法について異なる四つのアルゴリズムを提案し比較検討する. そして, このアルゴリズムの適用例を挙げ有効性を示す.