※一部利用できない機能があります
| 1.
論文 |
論文
|
Nakano, Tomoyuki ; Tanaka, Yasunori ; Murai, Kosuke ; Uesugi, Yoshihiko ; Ishijima, Tatsuo ; Tomita, Kensuke ; Suzuki, Katsumi ; Shinkai, Takeshi ; 田中, 康規 ; 上杉, 喜彦 ; 石島, 達夫
概要:
金沢大学理工研究域電子情報学系<br />This paper presents the arc quenching abilities of various gases studied using a power semiconducto
…
r switching technique. The technique uses an insulated gate bi-polar transistor (IGBT) to inject current and apply voltage to the plasma arc. Using this technique, arcs in free recovery condition after a 50 A steady state condition were investigated in SF6, CO2, O2, N2, air and Ar gas flows. Furthermore, at a specific time high voltages of about 1.1 kV and 1.7 kV μ were applied to the residual decaying arcs by the IGBT to elucidate the arc re-ignition process and recovery properties. These systematic experiments further enabled us to estimate the interruption probability versus the voltage application time. From these results, the voltage application time for 50% successful interruption was estimated for various gases, with the results showing a direct relation to the interruption capabilities of the respective gases. These results were then compared to the electron density measurement results and numerical simulation results to confirm their validity. All data obtained from the experiments and simulation is expected to be useful for elucidating the arc quenching physics and also for the practical application of arc quenching phenomena. © 2017 IOP Publishing Ltd.<br />Embargo Period 12 months
続きを見る
|
||||
| 2.
論文 |
論文
|
Tanaka, Yasunori ; Nakano, Tomoyuki ; Shimizu, Takahiro ; Tomita, Kentaro ; Fujino, Takayasu ; Suzuki, Katsumi
概要:
This paper has proposed a new fundamental investigation technique on arc behaviors in decaying and re-ignition processes
…
under gas flow condition. This technique utilizes power semiconductors like insulated-gate bipolar transistors (IGBTs) to control the arc current and voltage with a high accuracy in time domain. The free recovery condition was created by switching-on an IGBT connected in parallel with the arc device to investigate decaying process of the arc plasma under gas flow condition. Then, the quasi-transient recovery voltage (quasi-TRV) was intentionally applied between the electrodes in the arc device under the free recovery condition by turning-off the IGBT again, to study the re-ignition process of the arc plasma. At the same time, the arc behavior in a nozzle was observed by a high speed video camera at a frame rate of 200,000 fps. In the present work, arc behaviors in gas flow such as SF6 and CO2 in a nozzle was fundamentally investigated under free recovery condition and then after quasi-TRV application. In addition, the timing of the quasi-TRV application was changed to examine the recovery property of residual arcs in SF6 and CO2 gas flow. Through these experiments, the probability of arc successful interruptions were statistically measured for these gas flow arcs. These results provide fundamental data for comparison of the arc interruption capability of different conditions.<br />出版者照会後に全文公開
続きを見る
|
||||
| 3.
論文 |
論文
|
Nakano, Tomoyuki ; Murai, Kosuke ; Tanaka, Yasunori ; Uesugi, Yoshihiko ; Ishijima, Tatsuo ; Shiraishi, Tatsuro ; Shimizu, Takahiro ; Tomita, Kentaro ; Suzuki, Katsumi ; Shinka, Takeshi
概要:
This paper reports a new simple test technique to evaluate current interruption ability of arc quenching gases. In the t
…
est, current and voltage applied to the arc was controlled using a insulated gate bipolar transistor (IGBT). Switching the IGBT enables us to produce free recovery conditions for a fundamental arc decay in nozzles. In addition to this, a voltage was intentionally applied to the free recovery arcs between the electrodes by switching-off IGBT again at the specified delay time td. This applied voltage is called quasi transient recovery voltage (quasi-TRV). We can evaluate successful interruption or interruption failure by measuring the current between the electrodes after quasi-TRV application. We compared the interruption ability of SF6 and CO2 through this developed technique. The experimental results show that a residual arc in SF6 gas flow decays four times more rapidly than that in CO2 gas flow. Influence of observation holes in the nozzles used in the experiments was also investigated, showing less influence of observation on the arc behavior. © 2015 IEEE.
続きを見る
|
||||
| 4.
論文 |
論文
|
Negishi, Koroku
|
||||
| 5.
論文 |
論文
|
長谷川, 卓 ; Hasegawa, Takashi
概要:
金沢大学理工研究域地球社会基盤学系<br />本年度は,有孔虫の殻に閉じ込められた有機物の含有量について,現生底生有孔虫,化石底生有孔虫(膠着質,石灰質),現生浮遊性有孔虫について分析を行った結果,約0.1-0.4%の含有量を持っていること
…
が明らかになった.特に,浮遊性有孔虫ではその含有量の個体や種による差は小さいことがわかり,同位体分析のための適切な試料量が容易に推定できるようになった.そこに至るまでの過程で,様々な溶媒を用いたり,ふるいを自作するなどして効率的な準備方法を開発した.これらの作業は金沢大学で行った.これらの手法がほぼ確立したことを受け,実際に北海道大学地球環境科学研究院に設置の微量炭素の同位体比分析が可能な装置を用いて個別の種の浮遊性有孔虫(赤道太平洋の表層堆積物に含まれる現生浮遊性有孔虫)の殻構造内部に含まれる有機物の炭素同位体比を測定した(18年2月,3月).1個体の殻の重量が異なるため,分析に用いた有孔虫の個体数は種によって異なるが,Globorotalia menardiiでは100個体を用いて分析を行い,3回測定を繰り返すことができる程度の二酸化炭素ガスを得ることができた.Globigerinoides sacculiferでは400個体を用いることでほぼ同量のガスを得た.個別に処理したG.menardiiの4試料ではいずれも-24.35±0.3‰の範囲であった。このように開発した処理法は炭素同位体比の再現性が高いことが示すことができた.G.sacculiferでは1試料で-22.9‰,Globorotalia tumidaでは2試料から-23.72‰および-24.12%を得た.このように,種が異なっても同位体比値が大きく異なることがない.本研究の結果,有孔虫の殻体構造内に閉じ込められた有機炭素の同位体比分析の手法が確立した.今後,確立した手法を用いてデータを増やすことで,表層種と温度躍層種に系統的な差があるのかどうか,などが議論できる.また,実用面に関しては,限定した種を用いて有機炭素同位体比の経時変化を調べ,その炭酸塩炭素の同位体比との差を取り,その差が経時的にどのような変化を示すのか,を調査する次のステップに研究を進める段階に達した。<br />研究課題/領域番号:16654080, 研究期間(年度):2004 – 2005<br />出典：「有孔虫の殻内有機物を用いた地質時代の大気CO_2分圧プロキシの開発」研究成果報告書 課題番号16654080（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-16654080/)を加工して作成
続きを見る
|
