著者

Nobuo Nakada Norihide Fukuzawa Toshihiro Tsuchiyama Setsuo Takaki Tamotsu Koyano Takashi Iwamoto Yasuhiro Omori

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.53, no.1, pp.139-144, 2013 (Released:2013-01-15)

参考文献数

22

被引用文献数

10 13

---

In order to understand the mechanism of isothermal transformation of Fe–N alloy, the isothermal transformation microstructure that forms in a wide temperature range below Ae1 was investigated in Fe–2.6 mass%N hypereutectoid alloy by means of the electron back scatter diffraction method in addition to the conventional microstructural observation methods. High-nitrogen austenite fully decomposed to ferrite and Fe4N over the entire temperature range, and the time-temperature-transformation (TTT) diagram had a C shape with a nose temperature around 700 K. The hardness linearly increased with decreasing transformation temperature because the microstructure became finer, but the morphology of the (ferrite + Fe4N) structure changed discontinuously at around 800 K. From the microstructural and crystallographic analyses, it was concluded that the microstructure formed at higher temperature is a lamellar eutectoid structure, braunite, while the other is an upper bainitic structure containing bainitic ferrite formed through a displacive mechanism and Fe4N formed by concentration and ordering of the nitrogen. Since Fe4N is a counterpart of the cementite in Fe–C alloy, the respective structures are similar to pearlite and upper bainite in carbon steel.

著者

大森 康宏 Yasuhiro Omori

出版者

国立民族学博物館

雑誌

国立民族学博物館研究報告 = Bulletin of the National Museum of Ethnology (ISSN:0385180X)

巻号頁・発行日

vol.9, no.2, pp.421-457, 1984-08-31

---

The recording of image sequences on film, in other words makingmovies, is one of the principal activities in visual media. The moviewas developed for scientific purposes by Edward Maybridge. Hiscontinuous still photographs of the natural movements of animals andhumans not only provided the basis for further research, but alsorepresented the first instance of the ethnographic film. Subsequentproductions may be classified broadly as either fiction or documentaryfilms.With the development of portable devices for visual recording,the ethnographic film has come to be regarded as an integral part ofanthropological and ethnographic research. Ethnographic filmmakinghas yet to emerge as a definite genre within the field of anthropology.This paper examines certain features unique to ethnographic filmproduction, with particular emphasis on the process of shooting froman anthropological perspective. The ethnographic approach tofilming in field situations is also addressed.Theory and practice is a prerequisite to ethnographic film production,and the cameraman should therefore be a qualified ethnographerwith enough technical knowledge and experience to operate theequipment. Further, an understanding of the history of film ethnographynot only establishes the context within which production takesplace, but also often gives rise to new approaches to research design.In addition, before entering the field, the visual anthropologist isobliged to study general features of production, including patterns offilming, reportage, footage film, direct film, and cinema verite .In conclusion, emphasis has been attached to problems confront-ing the filmmaker under actual field conditions. This encompassesthe composition of the film staff as well as the responsibilities implicitin shooting under diverse social and environmental conditions. Noteven the production of a technically fine work can justify ignoringrelationships between the people filmed and the research team.