著者

永田 員也 日笠 茂樹 酒木 大助 小林 淳 三橋 いずみ 川口 亮 福武 和正 平尾 裕之

出版者

一般社団法人 日本接着学会

雑誌

日本接着学会誌 = Journal of the Adhesion Society of Japan (ISSN:09164812)

巻号頁・発行日

vol.37, no.8, pp.309-315, 2001-08-01

参考文献数

7

被引用文献数

2

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ヘンシェルミキサーを用い重質炭酸カルシウム(平均粒子径1.4mm)とタルク(3.2mm)をそれぞれ重量比3/1,1/1,1/3での混合と同時にステアリン酸による表面改質を行うことにより複合(ハイブリッド)フィラーを調製した。得られたハイブリッドフィラーおよび両者のフィラーを乾式で混合したブレンドフィラーをポリプロピレン(PP)に二軸押出機にて混練し,射出成形機で試料を調製した。これらフィラーの走査型電子顕微鏡観察の結果,ハイブリッドフィラーはブレンドフィラーと大きく異なり,混合時の衝突エネルギー,表面改質,粒子形状の違いなどにより微粒子炭酸カルシウムやタルクの凝集塊が十分に解砕されていた。ハイブリッドフィラー充填複合材料はそれぞれの粒子が均一にマトリックスに分散していた。得られた複合材料の力学特性を測定した結果,ハイブリッドおよびブレンドフィラー充填複合材料の弾性率や降伏強度はタルク配合比増加とともに向上し,タルクがこれらの力学特性改善効果に大きく寄与していることが明らかとなった。ブレンドフィラー充填複合材料ではタルク充填により衝撃強度が大きく低下した。一方,ハイブリッドフィラー充填複合材料の衝撃強度はフィラー充填量40%を除いてタルク含有量が10wt%以下ではマトリックスPPの38kJ・m-2よりも高い衝撃強度であり,炭酸カルシウムの配合比が高いほど優れた衝撃強度を示した。このハイブリッドフィラーの衝撃強度改善効果は解砕微粒子炭酸カルシウムの応力分散作用およびタルク凝集塊の解砕が主な要因であると考えられる。

著者

栁澤 宏彰 及川 輝樹 川口 亮平 木村 一洋 伊藤 順一 越田 弘一 加藤 幸司 安藤 忍 池田 啓二 宇都宮 真吾 坂東 あいこ 奥山 哲 鎌田 林太郎 兒玉 篤郎 小森 次郎 奈良間 千之

出版者

特定非営利活動法人 日本火山学会

雑誌

火山 (ISSN:04534360)

巻号頁・発行日

vol.67, no.3, pp.295-317, 2022-09-30 (Released:2022-10-27)

参考文献数

73

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The 2016 eruptions of Niigata-Yakeyama volcano in central Japan consisted of several small eruptions that were accompanied by syneruptive-spouted type lahars. We have reviewed the sequence of the 2016 activity and modeled the eruptive processes based on observations of various volcanic phenomena, including ash fall and lahars, plumes, earthquakes and crustal deformation, and analysis of eruptive products. Eruptions of Niigata-Yakeyama volcano after the 20th century can be categorized into two types; 1) VEI=0-1 eruptions during which ash fall covered only the summit area and no ballistic blocks were ejected (e.g., 1997-1998 event) and 2) VEI=1-2 eruptions during which ash fall reached the foot of the mountain with ejected blocks (e.g., 1974 event). We also discuss the characteristics of the 2016 activity by comparing the sequence with those of other events of Niigata-Yakeyama volcano: the 1974 and 1997-1998 eruption events and the 2000-2001 intensified fumarolic event. The 2016 eruptions of Niigata-Yakeyama volcano are divided into the following six stages. Stage I was characterized by the onset of intensified steam plume emission activity (≥200 m). Stage II was characterized by the onset of crustal deformation, slight increase of high frequency earthquakes (approx.>3.3 Hz) and further activation of steam plume emission activity (≥500 m). The crustal deformation observed commenced at the beginning of Stage II and lasted until the end of Stage V. The total inflated volume was estimated to be approximately 7.2×106 m3. Several very small eruptions that provided only a small amount of ash to the summit area also occurred. Stage III was characterized by a rapid increase of high frequency earthquakes accompanied by tilt change, and the onset of low frequency earthquakes (approx.<3.3 Hz). A small eruption was accompanied by a syneruptive-spouted type lahar at this time. Stage IV was characterized by the occurrence of several small syneruptive-spouted type lahars. The occurrence of high and low frequency earthquakes continued, but with decreasing abundance. Stage V was characterized by the highest altitude of steam plume emission (≥1,200 m), while no ash emission nor syneruptive-spouted type lahars were observed. Stage VI was characterized by a gradual decrease in steam plume emission and earthquake activity. The aerial photographs indicate the ash fall distribution, and the maximum scale of the 2016 eruption, which is estimated to be VEI=1. The assemblage of altered minerals indicates that the volcanic ash originated from volcanic conduits affected by a high-sulfidation epithermal system and no magmatic components were detected. Judging from the depth of the crustal deformation source of magmatic eruptions at other volcanoes, the estimated source of crustal deformation during the 2016 eruption is considered to have been caused by a volume change of the magma chamber. The sequence of the 2016 event can be interpreted as follows: 1) magma supply to the magma chamber, 2) increase in seismicity and fumarolic activity triggered by volcanic fluid released from the new magma, 3) destruction of volcanic conduit by increased fumarolic activity and emission of volcanic ash, and 4) occurrence of syneruptive-spouted type lahars by the “airlift pump” effect. At Niigata-Yakeyama volcano, such small eruptions and fumarolic events have been frequently observed for the last 40 years. We thus consider that the accumulation of magma has progressed beneath the volcano, which is a potential preparatory process for a future magmatic eruption.

著者

西村 太志 井口 正人 川口 亮平 Surono Muhamad Hendrasto Umar Rosadi

出版者

特定非営利活動法人 日本火山学会

雑誌

日本火山学会講演予稿集 2010 (ISSN:24335320)

巻号頁・発行日

pp.26, 2010-10-09 (Released:2017-02-10)

著者

岡部 匡 川口 亮

出版者

一般社団法人日本機械学会

雑誌

日本機械学会九州支部講演論文集

巻号頁・発行日

vol.2009, no.62, pp.181-182, 2009-03-18