| Project/Area Number |
17K05631
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Solid earth and planetary physics
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| Research Institution | Nagoya University |
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Principal Investigator |
SIRONO Sin-iti 名古屋大学, 環境学研究科, 准教授 (20332702)
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| Co-Investigator(Kenkyū-buntansha) |
桂木 洋光 名古屋大学, 環境学研究科, 准教授 (30346853)
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| Project Period (FY) |
2017-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2017: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | ダストアグリゲイト / 焼結 / 微惑星 / 形成場所 / バネ定数 / 衝突 / 微粒子集合体 / 有限要素法 / 力学的応答 / 原始惑星系円盤 / 室内実験 / 数値シミュレーション |
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| Outline of Final Research Achievements |
Mechanical properties of dust aggregates strongly affect the first step of planetary formation. If elasticity of an aggregate is large, the collisioncal outcome of aggregates becomes bouncing and growth to planets is prohibited. In this study, elasticity between dust grains was determined as a function of the degree of sintering, which is an efficient mechanism in a protoplanetary nebula. There are four modes of deformation: 1: stretching 2: rolling 3: sliding 4: stretching. The determined elasticity for stretching was smaller than that in previous model. Empirical formulas were derived for the elasticities. The collisional simulation was conducted to check the effect of the modified elasticity. The collisional outcome of numerical simulation was not changed.
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| Academic Significance and Societal Importance of the Research Achievements |
焼結したダストアグリゲイトの弾性率を明らかにし，その結果をもとにして数値シミュレーションを行なったところ，衝突の結果が合体から跳ね返りに転じる可能性が非常に高くなることが明らかとなった．ここから，惑星は焼結が起こらない領域でのみ形成しうると考えられる．惑星の形成場所が焼結によって決定さうるということは，原始惑星系円盤の観測結果からも示唆されている．
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