著者

Mariko NAGASHIMA Daisuke NISHIO–HAMANE Shuichi ITO Takahiro TANAKA

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.116, no.3, pp.129-139, 2021 (Released:2021-07-17)

参考文献数

23

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Ferriprehnite (IMA2020–057), ideal formula Ca2Fe3+(AlSi3)O10(OH)2, is a new mineral that was found as secondary mineral in druses developed in the hydrothermal altered dolerite from Kouragahana, Shimane Peninsula, Japan. Ferriprehnite is an Fe analogue of prehnite. The crystals consisting of ferriprehnite and prehnite occur as a radial aggregate. The tabular crystals are up to 300 µm long, 100 µm wide, and 50 µm thick. Ferriprehnite is colorless to pale green with white streak and vitreous luster. It has a Mohs hardness of 6½. Its cleavage is good on {100}. The calculated density is 2.97 g/cm3. The empirical formula of ferriprehnite on the basis of 10O + 2OH using the result obtained by electron microprobe analysis is Ca1.99(Fe3+0.66Al0.34)Σ1.00(Al1.02Si2.98)Σ4.00O10(OH)2. Structure refinement converged to R1 = 4.64%. Its space group is orthorhombic Pma2 with unit–cell parameters a = 18.6149(10) Å, b = 5.4882(3) Å, c = 4.6735(3) Å, and V = 477.46(1) Å3. The determined site occupancy at the octahedral M site is Fe0.637(9)Al0.363 indicating that the M site is predominantly occupied by Fe. <M–O> increases with increasing Fe content leading to isotropic expansion of MO6 octahedra. The a– and c– dimensions of ferriprehnite are longer than those of prehnite due to Fe substitution for Al at the M site.

著者

Daisuke NISHIO–HAMANE Takahiro TANAKA Tadashi SHINMACHI

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.5, pp.252-262, 2019 (Released:2019-12-05)

参考文献数

30

被引用文献数

8

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Minakawaite, a new mineral with a RhSb composition, in association with a platinum–group mineral (PGM) placer is found from a small stream crossing the clinopyroxenite mass in serpentinite mélange of the Kurosegawa belt on the northeast side of Hikawa Dam, Haraigawa, Misato machi, Kumamoto Prefecture, Japan. Almost all PGM placer grains are based on isoferroplatinum, of which the rims are often covered by tulameenite and tetraferroplatinum. This isoferroplatinum–based grain contains small inclusions and accessories consisting mainly of osmium, erlichmanite, laurite, bowieite, cuprorhodsite, and ferhodsite–like mineral. Minakawaite occurs as the outmost surface layer with a rose gray metallic luster on the nub consisting of cuprorhodsite, ferhodsite–like mineral and/or Rh(Ge,Cu,Fe) mineral in association with an isoferroplatinum–based grain. The density of minakawaite is 10.04 g/cm3, calculated using the empirical formula and powder X–ray diffraction (XRD) data. Minakawaite has a pale gray color under the microscope in reflected light, and pleochroism is weak as a variation from pinkish pale gray to bluish pale gray. Anisotropy is moderate as reddish gray to bluish gray. Average results of ten energy dispersive X–ray spectroscopy (EDS) analyses give Rh 46.83, Sb 48.97, As 4.08 and total 99.88 wt%. The empirical formula is Rh0.998(Sb0.882As0.120)Σ1.002, based on 2 atoms per formula unit. Minakawaite is orthorhombic (Pnma) with a = 5.934(7) Å, b = 3.848(3) Å, c = 6.305(4) Å, and V = 144.0(2) Å3 (Z = 4). The seven strongest lines of minakawaite in the powder XRD pattern [d in Å(I /I0) (hkl )] are 2.860(63) (111), 2.774(35) (102), 2.250(47) (112), 2.199(100) (211), 2.162(38) (202), 1.923(49) (020), and 1.843(51) (013). Minakawaite is identical to the synthetic RhSb phase with MnP–type structure. PGM including minakawaite may occur with chromite in the magma chamber of the clinopyroxenite. Minakawaite was named in honor of Japanese mineralogist, Prof. Tetsuo Minakawa (b. 1950) of Ehime University for his outstanding contribution to descriptive mineralogy from Kyushu and Shikoku, Japan.

著者

田中 隆博 Takahiro Tanaka

雑誌

人工知能学会誌 = Journal of Japanese Society for Artificial Intelligence (ISSN:09128085)

巻号頁・発行日

vol.24, no.3, pp.376-384, 2009-05-01

著者

Hiroshige Tateuchi Toshihiko Yoneda Takahiro Tanaka Hitoshi Kumada Masahiro Kadota Hiroshi Ohno Kazunari Tanaka Jun Yamaguchi

出版者

The Society of Physical Therapy Science

雑誌

Journal of Physical Therapy Science (ISSN:09155287)

巻号頁・発行日

vol.18, no.1, pp.49-55, 2006 (Released:2006-07-26)

参考文献数

22

被引用文献数

4 5

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The purpose of this study was to clarify the postural control of the initiation of lateral step and step-up motions in healthy young adults (24.3 ± 1.8 years: mean ± SD). The tasks involved the lateral step (step lengths, 10 cm and 20 cm) and lateral step-up motions (10-cm high stool; step lengths, 10 cm and 20 cm). The variables for analysis included motion duration (weight-shift phase and swing phase), shifts of the center of pressure (CoP) and the center of gravity (CoG), displacement and inclination of the shoulder and the pelvis, and root mean square electromyographic amplitude of the erector spinae, gluteus medius (GM) and adductor longus (AL) bilaterally. The CoP shift toward the stepping side was larger in the step-up task than in the step task, and it was smaller when both tasks were performed in the long lengths. The CoG shift toward the supporting side and the displacements of the shoulder and pelvis were larger in the step-up task than in the step task. However, the magnitude of GM activity of the supporting leg was larger in the step task than in the step-up task, and increased when both tasks were performed in the long lengths. In the stepping leg, the magnitude of AL activity was larger in the step-up task than in the step task, and decreased when both tasks were performed in the long lengths. These results suggest that GM activity of the supporting leg and AL activity of the stepping leg control the shift of CoG in the frontal plane. Our results indicate that the increase in GM activity does not depend on the height of stepping but on the length of stepping in lateral step and step-up motions.