Faculty Profiles - MATSUOKA Jun

Presentations -

Division display81 - 100 of about 146／ All the affair displays >>

Thermal properties and viscosity of isotope substituted borate glasses: concept of vibrational connectivity Invited International conference

Jun Matsuoka

The 9th Internat. Conf. BORATE GLASSES, CRYSTALS AND MELTS and The 2nd Internat. Conf. PHOSPHATE GLASSES, CRYSTALS AND MELTS 2017.7 the Society of Glass Technology

Language：English Presentation type：Oral presentation (invited, special)

Venue：Oxford, UK

Mixing of 11B and 10B in borate glass increases the low temperature heat capacity and decreases the thermal diffusivity. These can be explained by the localization of atomic vibration. Mixing of them also causes the decrease of viscosity which will be due to the inhibition of cooperative motion. Borosilicate glasses can be separated to two groups; one shows the mixed isotope effect in viscosity and the other doesn’t. This difference should be due to the difference of dominant atomic process in viscose flow.

押し込み試験中のガラス応力分布評価とその圧子形状依存性

浅井敬祐, 吉田智, 山田明寛, 松岡純, アンドレイ・エラパルト,チャールズ・カ－キャン

日本セラミックス協会関西支部第12回学術講演会 2017.7 日本セラミックス協会

Language：Japanese Presentation type：Poster presentation

Venue：京都

ガラスのクラックの発生挙動は押し込み試験により評価されている。ダイヤモンド製鋭角圧子をガラスに押し込むと変形痕が生じ、押し込み荷重の増加とともにクラックが発生する。このクラックの発生しやすさやクラックの形状は、ガラス組成や圧子形状に依存することが知られているが、押し込み試験中に連続的に変化する応力場と、発生するクラックの形状や発生タイミングとの関係はほとんど理解されていない。そこで本研究では光弾性応力解析法により押し込み負荷除荷試験中のガラスの応力分布を決定した。顕微光弾性測定により、圧子押し込み試験中のガラス内部の応力分布の測定に初めて成功した。押し込み負荷中は、ガラス表面に引張り応力が発生し、この応力がリングクラックの原因になると考えられた。鋭い圧子を用いると除荷過程に押し込み軸直下に引張り応力が発生し、この応力がメジアン/ラジアルクラックの原因になると考えられた。

CaO-SiO2融液におけるソレー効果の分子動力学計算

清水雅弘, 加藤寛, 加藤毅之, 松岡純, 西正之, 平尾一之

日本セラミックス協会関西支部第12回学術講演会 2017.7 日本セラミックス協会

Language：Japanese Presentation type：Oral presentation (general)

Venue：京都

分子動力学計算によってケイ酸塩融液においてはじめてSiO2が低温側に移動する挙動を見出した。分子動力学計算と理論モデルの熱力学部分の比較では、SiO2濃度分布の逆転が両方で生じており(ただし15 mol%の差がある)、また単調減少が一致しており、かつ分子動力学計算結果に約4×10-4 K-1を加えるとよく重なる。CaO-SiO2系融液のソレー効果の理論予測式として既存のモデルを一部改変し新しい式を提案した。

Intrinsic strength of germanate glasses International conference

K. Katsumi, S. Yoshida, A. Yamada, J. Matsuoka,Y. Kato, H. Yamazaki

7th International Workshop on Flow and Fracture of Advances Glasses 2017.7 Organizing Committee of FFAF-7

Language：English Presentation type：Oral presentation (general)

Venue：Aalborg, Denmark

Two-point bending(2PB) tests were performed for Na2O-SiO2-GeO2 and Na2O-B2O3-GeO2 glass fibers. 2PB failure strain (or strength) increases with increasing 6-coordinated Ge in glass. Some inelastic dissipation energy at failure may result in high-strength germanate glasses. We should look at such permanent structural change in glass under high stress to design ‘High-strength’ glass.

Composition dependence of crack formation probability in aluminoborosilicate glass International conference

H. Morozumi, S. Yoshida, J. Matsuoka

7th International Workshop on Flow and Fracture of Advances Glasses 2017.7 Organizing Committee of FFAF-7

Language：English Presentation type：Oral presentation (general)

Venue：Aalborg, Denmark

Relationship between composition, crack resistance and structure was investigated for aluminoborosilicate glasses. The crack resistance suddenly decreases when the ratio of (Q3+Q4)/(Q2+Q3+Q4) is less than ca. 0.7. In series B, crack resistance increases with increasing four-coordinated boron units. By the addition of a small amount of B2O3, the glass can be produced with improved productivity, effective ion-exchange rate, and higher crack resistance.

In-situ observation of the structural change in MgO-B2O3-SiO2 glass at high pressure International conference

A. Yamada, M. Harada, A. Masuno, K. Yamanaka, K. Mitsuhara, S. Yoshida, J. Matsuoka

The 12th Pacific Rim Conference on Ceramic and Glass Technology 2017.5 American Ceram. Soc., Australian Ceram. Soc., Ceram. Soc. Japan, Chinese Ceram Soc., Korean Ceram. Soc.

Language：English Presentation type：Poster presentation

Venue：Waikoloa, Hawaii, USA

The structural change in magnesium borosilicate glass under hydrostatic pressure was investigated by high-pressure Raman spectroscopy. The elastic moduli of the glass showed relatively higher value compared with Na2O-B2O3-SiO2 glass. The structure of as-made glass was investigated by B and Mg k-edge x-ray absorption near edge structure (XANES), which indicate that the coordination number of B could be almost 3 and that Mg may have higher coordination number. The structural response in compression was examined within diamond anvil cell, up to 8 GPa. As for silicate group, Q2 and Q3 structure were responsible to compression. The silicate network becomes polymerized with pressure. However, the structural change was almost reversible. On the borate group, metaborate group, which consists of three triangular boron with one non-bridging oxygen, decreased with pressure. In contrast, triborate group, which includes four-fold coordinated boron and has fully polymerized borate network, increased.

High Temperature Properties of Glass for Processing Invited

Jun Matsuoka

2nd Symposium on Advanced Processing of Glass 2017.3 The National Institute of Advanced Industrial Science and Technology (AIST), Kyoto University

Language：Japanese Presentation type：Oral presentation (invited, special)

Venue：Osaka

High temperature properties of glass melts were reviewed in relation to the advanced processing of glass. The review is mainly composed of stdies done by the author's research group. It contains viscosity, density, heat capacity, optical absorption and heat transfer, electrical conduction, redox equilibria, and relaxation around Tg.

Electrochemical reaction of soda-lime silicate glass melt under alternating voltage application International conference

S. Nakai, S. Yoshida, A. Yamada, J. Matsuoka, Y. Miura, Y. Katagami, Y. Kii, N. Yoshida, M. Kawaguchii

日米ガラス部会－GOMD 合同国際ガラス科学技術シンポジウム第57 回ガラスおよびフォトニクス材料討論会 2016.11 日本セラミックス協会, The American Ceramic Society

Intrinsic Strength and Structure of Germanate Glasses International conference

K. Katsumi, S. Yoshida, A. Yamada, J. Matsuoka, Y. Kato, H. Yamazaki

The local structure of Na2O-MgO-B2O3 glass

A. Yamada, S. Izumi, K. Yamanaka, K. Mitsuhara, S. Yoshida, J. Matsuoka