著者

村上 敬宜 高橋 宏治 山下 晃生

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 A編 (ISSN:03875008)

巻号頁・発行日

vol.63, no.612, pp.1612-1619, 1997-08-25 (Released:2008-02-21)

参考文献数

21

被引用文献数

10 43

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In order to investigate the effect of surface roughness on fatigue strength, fatigue tests for a medium carbon steel, which was annealed and free of residual stress (HV≅170) and quenched and tempered (HV≅650). were carried out. To simulate the actual surface roughness, extremely shallow periodical notches with a constant pitch but irregular depth were introduced. The equivalent defect size √(area)R for roughness was defined to evaluate the effect of irregularly shaped roughness using the √(area) parameter model. The fatigue limits of the annealed medium carbon steel specimens with artificial surface roughness are much higher than those of the specimen with a single notch because of the interference effect of notches. The fatigue limits predicted by the √(area) parameter model are in good agreement with the experimental results.

著者

高橋 宏治

出版者

公益社団法人 計測自動制御学会

雑誌

計測と制御 (ISSN:04534662)

巻号頁・発行日

vol.52, no.12, pp.1116-1121, 2013-12-10 (Released:2018-04-25)

参考文献数

11

被引用文献数

1

著者

定森 友也 高橋 宏治 古池 仁暢

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.851, pp.17-00096-17-00096, 2017 (Released:2017-07-25)

参考文献数

11

被引用文献数

1

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In this study, the effect of shot peening on rolling contact fatigue life of bearing steel was investigated under contaminated lubrication. Shot peening was carried out on bearing steel SUJ2 specimens. Peened specimens were polished to remove the dimples generated by shot peening. The distribution of Vickers hardness and residual stress of the specimens were measured before and after the shot peening. The resistance to indentations was compared by examining the profile of the Vickers indentations. Then, rolling contact fatigue tests were carried out under contaminated lubrication. The material hardness was improved up to about 100 HV on the surface to a depth of 300 μm, and compressive residual stress was generated up to 1546 MPa at a depth of 25 μm due to the shot peening. In addition to the width and the depth of the Vickers indentation, the ridge height which causes the stress concentration around the indentation, was reduced by 17% by the shot peening. The rolling contact fatigue life associated with a 50% reliability (L50) was improved 62 % by the shot peening. However, the improvement of rolling contact fatigue life associated with a 90% reliability (L10) was only 26 % because of the increase in dispersion of the fatigue lives due to surface cracks created by the shot peening. Based on the present result, the increase of surface hardness and generating the large compressive residual stress near the surface by shot peening was found to be effective in increasing the rolling contact fatigue life in contaminated lubrication.

著者

渡邉 廉也 高橋 宏治 多田 和弘 石村 春令

出版者

一般社団法人 日本透析医学会

雑誌

日本透析医学会雑誌 (ISSN:13403451)

巻号頁・発行日

vol.47, no.12, pp.755-759, 2014 (Released:2014-12-22)

参考文献数

8

被引用文献数

1

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症例は糖尿病歴10年の65歳女性. 2014年2月上旬, 近医にてインフルエンザBと診断され, オセルタミビル, クラリスロマイシンの内服治療を開始した. 2週間後, 徐々に尿量が低下し, 嘔吐, 全身倦怠感が出現したため, 2月中旬, 当院夜間内科外来を受診した. 来院時検査にて著明な高K血症, 腎機能障害を認め, 緊急透析を施行し入院となった. 2回目の透析後より徐々に, 尿量が改善し血液透析を2回施行し離脱した. その後, 全身状態が軽快し退院となった. 急性腎障害の原因はさまざまであるが, 本症例は受診までの経過, 来院後の検査結果からオセルタミビルとクラリスロマイシンを被疑薬とする薬剤性腎障害が最も考えられた. 両薬剤とも日常診療で頻繁に使用される薬剤であり, 投与後の経過には注意が必要である.