著者

Susumu IKEDA Takuma DOI Keizaburo UCHIKAWA Yoshiharu KURITA

出版者

公益社団法人 計測自動制御学会

雑誌

計測自動制御学会論文集 (ISSN:04534654)

巻号頁・発行日

vol.29, no.3, pp.245-252, 1993-03-31 (Released:2009-03-27)

参考文献数

8

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The existence of intrinsic vertical effects of spinning gyroscopes was examined systematically from the viewpoint of precise measurement, using three types of gyroscopes with largely different characteristics. The most precise weighing techniques, such as a reference tare system and various countermeasures, were applied. Slight and symmetrial mass changes observed in the experiment were explained as the parasitic effect of the balance due to the torque of the spinning gyroscopes, utilizing the attenuation constant change under atmospheric conditions. Consequently, the intrinsic vertical effects were found to be virtually zero in this experiment, and even if existent, were estimated to be neither greater than +0.7mg nor less than -0.5mg at a 99% confidence level for the angular momentum of 0.936kg·m2/s.

著者

Susumu IKEDA Yoshito NAKASHIMA Tsukasa NAKANO

出版者

Japan Association of Mineralogical Sciences

雑誌

Journal of Mineralogical and Petrological Sciences (ISSN:13456296)

巻号頁・発行日

vol.114, no.1, pp.1-17, 2019 (Released:2019-03-08)

参考文献数

53

被引用文献数

1

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The three–dimensional (3–D) structure of crystals around the interface between massive potassium (K)–feldspar and quartz–feldspar intergrowth (graphic granite) of two samples collected from a pegmatite body in Ishikawa town, Fukushima Prefecture, Japan, was determined by X–ray computed tomography (CT). Based on the results and additional information obtained by serial thin section and polarizing observations, the formation processes of graphic granite and pegmatite bodies are discussed. The most important finding of the 3–D observation using X–ray CT is the very flat spatial distribution of the tips of the quartz crystals. The sharp interface between the graphic and single–phase parts suggests that the change from graphic granite to massive K–feldspar crystallization corresponds to the transition of the thermodynamic conditions at the growth front from non–equilibrium to equilibrium. This indication leads to a new model for the pegmatite genesis, that is, graphic granite forms at the marginal zone under non–equilibrium conditions shortly after the intrusion of magma due to rapid cooling by the cold host rock body and, subsequently, the crystallization of massive K–feldspar starts when the conditions at the crystal growth front reenter the ‘feldspar + melt’ field in the phase diagram due to the relaxation of the conditions. Other results related to the conditions of the growth environment with coexisting aqueous fluid, such as the connectivity of the quartz crystals, are also discussed, for example, the influence of the supercritical state on the nucleation of quartz crystals.