- 著者
- Paul K. B. ALANIS Yusuke YAMAYA Akihiro TAKEUCHI Yoichi SASAI Yoshihiro OKADA Toshiyasu NAGAO
- 出版者
- The Japan Academy
- 雑誌
- Proceedings of the Japan Academy, Series B (ISSN:03862208)
- 巻号頁・発行日
- vol.89, no.8, pp.383-389, 2013-10-11 (Released:2013-10-11)
- 参考文献数
- 20
- 被引用文献数
- 8 15
Taal Volcano is one of the most active volcanoes in the Philippines. The magnetotelluric 3D forward analyses indicate the existence of a large high resistivity anomaly (∼100 Ω·m) with a volume of at least 3 km × 3 km × 3 km, which is capped by a conductive layer (∼10 Ω·m), beneath the Main Crater. This high resistivity anomaly is hypothesized to be a large hydrothermal reservoir, consisting of the aggregate of interconnected cracks in rigid and dense host rocks, which are filled with hydrothermal fluids coming from a magma batch below the reservoir. The hydrothermal fluids are considered partly in gas phase and liquid phase. The presence of such a large hydrothermal reservoir and the stagnant magma below may have influences on the volcano’s activity. Two possibilities are presented. First, the 30 January 1911 explosion event was a magmatic hydrothermal eruption rather than a base-surge associated with a phreato-magmatic eruption. Second, the earlier proposed four eruption series may be better interpreted by two cycles, each consisting of series of summit and flank eruptions.(Communicated by Seiya Uyeda, M.J.A.)
- 著者
- Rie Kurata Yoshihiro Okada Takeo Sakaigaichi Yumi Kai Akira Kobayashi Keisuke Suematsu
- 出版者
- The Japanese Society for Horticultural Science
- 雑誌
- The Horticulture Journal (ISSN:21890102)
- 巻号頁・発行日
- pp.QH-103, (Released:2023-12-28)
We investigated the anthocyanin composition of the purple sweet potato cultivar ‘Churakanasa’. The color tone of the paste was compared by L*, a*, and b* values and ‘Churakanasa’ exhibited a lower b* value, which indicates a bluish tint, than ‘Churakoibeni’, a popular cultivar for paste processing in Okinawa. High performance liquid chromatography (HPLC) analysis of the pigment extract showed that the anthocyanin composition of ‘Churakanasa’ was quite different from that of ‘Ayamurasaki’ and ‘Churakoibeni’. The analysis of the aglycone composition revealed that the cyanidin content (%) of ‘Ayamurasaki’ and ‘Churakoibeni’ contained 19.2% and 22.6% of cyanidins and 80.8% and 77.4% of peonidins, respectively. These findings indicate that these cultivars belong to the peonidin type. In contrast, ‘Churakanasa’ contained 86.4% cyanidin, indicating it to be a cyanidin-type cultivar. The steamed sweet potato paste made from ‘Churakanasa’ (cyanidin type cultivar) exhibited a bluer color compared to the peonidin-type cultivars. This observation suggests a direct correlation between the higher cyanidin content and the blue color intensity of the paste. HPLC-MS analysis of the two major HPLC peaks (peak I and II) of ‘Churakanasa’ suggested that the substance in peak I was YGM-0c; cyanidin-3-p-hydroxybenzoyl sophoroside-5-glucoside by mass, whereas peak II was YGM-1a; cyanidin-3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside. ‘Churakanasa’ exhibits unique color and pigment characteristics as it is the only purple sweet potato cultivar that has YGM-0c and -1a as its primary pigments.