著者

赤沢 宏 山本 賢二

出版者

公益社団法人 日本放射線技術学会

雑誌

日本放射線技術学会雑誌 (ISSN:03694305)

巻号頁・発行日

vol.57, no.8, pp.947-952, 2001-08-20 (Released:2017-06-30)

参考文献数

5

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The fracture of the calcaneus frequently involves the surface of the posterior talocalcaneal joint. Therefore, the Anthonsen position, which is effective for visualizing the posterior talocalcaneal joint surface, should always be indicated in patients suspected of fracture of the calcaneus. The Anthonsen I position, however, requires x-ray irradiation at an angle of 25° in the head and caudal directions and at 30° in the dorsoventral direction, which frequently results in the need for repeated x-ray examinations due to orientation errors. An alternative approach is to conduct x-ray examination using a tilting table adjusted to an angle of 25° or to carry out x-ray examination at a position of 45° heel lift. The adoption of these techniques enables relatively unconstrained visualization of the talocalcaneal joint, although x-ray examination in the heel lifting position may cause stress to patients suffering post-traumatic pain. The reproducibility of post-traumatic, preoperative and postoperative projections, however, is poor. As a solution to these problems, we have developed a new x-ray examination technique. The incident x-ray angle has been simplified by synthesizing the two angles used with the Anthonsen I position. Furthermore, the position of the foot is determined by means of an auxiliary projection device. Our simplified version of the Anthonsen I position reduces the number of projection processes and does not require the patient to adopt an awkward position. In addition, this modified technique enables the visualization of the posterior talocalcaneal joint surface as clearly as with conventional x-ray examination.

著者

村木 正芳 中村 健太 鈴木 真 瀬上 高博 山本 賢二

出版者

一般社団法人 日本トライボロジー学会

雑誌

トライボロジスト (ISSN:09151168)

巻号頁・発行日

vol.59, no.8, pp.507-514, 2014-08-15 (Released:2018-02-23)

参考文献数

11

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Tribological performances of the oils containing polylaurylacrylates with and without hydroxyethyl group were studied under elastohydrodynamic lubrication (EHL), partial EHL and the boundary lubrication conditions. The base oil was polyalphaolefin and the viscosity of polymer solutions and the concentration of polymer was adjusted at the same level. Under the partial elastohydrodynamic contacts using a ball-on-disk type tribometer, polylaurylacrylatehydroxyethylacrylate (PLA/HEA) showed a greater oil film thickness while lower traction coefficient at low rolling speeds than polylaurylacrylate (PLA). This can be interpreted that adsorption of hydroxyethyl group of PLA/HEA reduced traction under the partial EHL condition. Under the boundary lubrication conditions using a pin-on-disk type tribometer, PLA/HEA exhibited the flat friction-velocity relation while PLA showed a large negative gradient of friction-velocity relation. Finally, PLA/HEA was superior to PLA in terms of the antiwear properties with a reciprocating friction tester. It is inferred that these better performances of PLA/HEA under the boundary lubrication conditions were brought about by formation of a tribofilm based on reaction of hydroxyethyl group and the sliding surface.