ライブラリ登録: Guest
Plasma Medicine

年間 4 号発行

ISSN 印刷: 1947-5764

ISSN オンライン: 1947-5772

SJR: 0.216 SNIP: 0.263 CiteScore™:: 1.4 H-Index: 24

Indexed in

Active Species Concentrations in Pure N2 and Ar/x%N2 Flowing Late Afterglows at Reduced Pressure: Implications for the Sterilization of the Medical Instrumentation

巻 2, 発行 1-3, 2012, pp. 1-18
DOI: 10.1615/PlasmaMed.2013005816
Get accessDownload

要約

The present paper is devoted to the characterization of the late afterglow region of N2 and Ar−N2 flowing discharges. Optical emission spectroscopy is used to quantify the concentrations of the chemical species able to interact with microorganisms in the treatment chamber. Herein, we show that the production of nitrogen atoms in the afterglow of a reduced-pressure flowing microwave discharge can be increased using Ar−N2 mixtures instead of pure nitrogen. At 45 cm from the discharge, the maximum concentration of atoms, obtained for the Ar−15%N2 mixture, is 2.2 × 1021 m−3 at 9 Torr with an injected microwave power PMW of 100 W and 2.9 × 1021 m−3 at 200 W. Compared with the maximum N atom concentrations obtained in pure nitrogen at 4 Torr, this result corresponds to an increase of 120% at 100 W and 45% at 200 W.
We have verified that these results can be obtained while conserving full late afterglow conditions at a temperature equal to the room temperature at 100 W and not exceeding 35°C at 200 W. Under such conditions, the concentrations of the NO(A and B) excited states, formed from the impurities of the flowing gas, are low. For pure nitrogen, the concentration of the N2(A) metastable state was also measured at the end of the pink afterglow, where it is assumed to be maximal; it was 2.5 × 1016 m−3.
Nitrogen atoms are the major reactive species in the late afterglow region. They are believed to be responsible for the antibacterial properties of pure N2 and Ar−N2 flowing afterglows. To verify this assumption, the Ar−15%N2 flowing afterglow was applied to inactivate Escherichia coli bacteria, and the results were compared with previous studies performed in pure nitrogen and using the same microbiological protocol. With 40 min of exposure to Ar−15%N2 afterglow ([N] = 2.9 1021 m−3) at 32°C, a 6 log decrease of the initial bacteria population was obtained, while the same 6 log reduction could only be reached at 60°C with pure nitrogen afterglow ([N] = 1.0 × 1021 m−3).

によって引用された
  1. Kramer Axel, Matthes Rutger, Bekeschus Sander, Bender Claudia, Napp Matthias, Lademann Olaf, Lademann Jürgen, Weltmann Klaus Dieter, Aktueller und perspektivischer Einsatz kalter Plasmen aus hygienischer Indikation, in Plasmamedizin, 2016. Crossref

Begell Digital Portal Begellデジタルライブラリー 電子書籍 ジャーナル 参考文献と会報 リサーチ集 価格及び購読のポリシー Begell House 連絡先 Language English 中文 Русский Português German French Spain