Reactive species in cold atmospheric-pressure He+Air plasmas: The influence of humidity

2019 ◽  
Vol 26 (6) ◽  
pp. 063514 ◽  
Author(s):  
Bowen Sun ◽  
Dingxin Liu ◽  
Xiaohua Wang ◽  
Zhichao Liu ◽  
Felipe Iza ◽  
...  
2018 ◽  
Vol 197 ◽  
pp. 02013 ◽  
Author(s):  
Andi Wibowo Kinandana ◽  
Sumariyah Sumariyah ◽  
Muhammad Nur

Plasma-activated medium (PAM) has been produced by exposing a liquid media to Argon plasma jet. The jet plasma exposure to liquid media has produced reactive Oxygen species (ROS) in liquid phase. This study aims to determine the number of reactive species in plasma-activated medium. An atmospheric pressure plasma jet (APPJ) was generated with a dielectric barrier discharge (DBD) column by AC high voltage. Some parameters varied including exposure time; i.e. 5, 10, 15, 20, 25, and 30 min; and the distance between reactor and active media; i.e. 1, 2 and 3 cm. Some analysis conducted including variation of exposure times, the distances of reactor to PAM which affect produced concentration, and the reactive species composition in plasma-activated medium. In addition, temperature characteristics, pH levels, dissolved ozone and dissolved hydrogen peroxide concentrations were also observed in this study. The results showed that increased exposure time resulted in decreased pH, increased temperature and increased concentrations of ozone and hydrogen peroxide. The maximum reactive species composition was obtained at the distance between reactor and plasma-activated medium of 2 cm. Maximum reactive species composition obtained in this study has temperature of 29-30 Celsius degrees; pH 3.5; dissolved ozone 2.97 ppm; and Hydrogen Peroxide 215 ppm.


2020 ◽  
Vol 10 (19) ◽  
pp. 6898
Author(s):  
Lars Boeckmann ◽  
Mirijam Schäfer ◽  
Thoralf Bernhardt ◽  
Marie Luise Semmler ◽  
Ole Jung ◽  
...  

Plasma medicine is gaining increasing attention and is moving from basic research into clinical practice. While areas of application are diverse, much research has been conducted assessing the use of cold atmospheric pressure plasma (CAP) in wound healing and cancer treatment—two applications with entirely different goals. In wound healing, a tissue-stimulating effect is intended, whereas cancer therapy aims at killing malignant cells. In this review, we provide an overview of the latest clinical and some preclinical research on the efficacy of CAP in wound healing and cancer therapy. Furthermore, we discuss the current understanding of molecular signaling mechanisms triggered by CAP that grant CAP its antiseptic and tissue regenerating or anti-proliferative and cell death-inducing properties. For the efficacy of CAP in wound healing, already substantial evidence from clinical studies is available, while evidence for therapeutic effects of CAP in oncology is mainly from in vitro and in vivo animal studies. Efforts to elucidate the mode of action of CAP suggest that different components, such as ultraviolet (UV) radiation, electromagnetic fields, and reactive species, may act synergistically, with reactive species being regarded as the major effector by modulating complex and concentration-dependent redox signaling pathways.


2013 ◽  
Vol 10 (8) ◽  
pp. 686-697 ◽  
Author(s):  
Ho Young Kim ◽  
Sung Kil Kang ◽  
Hyoung Cheol Kwon ◽  
Hyun Woo Lee ◽  
Jae Koo Lee

A technique has been developed for measuring the diffusion coefficients of atoms and other reactive species in gases below atmospheric pressure. The technique consists of measuring the rate of dispersion of a pulse of reactive species in a stream of gas flowing rapidly ( ca . 10 m s -1 ) down a quartz tube. The reactive species are observed and the profile of the pulses measured by using resonance fluorescence. The technique has been used at room temperature, but in principle measurements could be made at elevated temperatures. Measurements have been made of the rates of diffusion of hydrogen atoms in argon and nitrogen, and values for the diffusion coefficients of 1.61 ± 0.04 and 1.35 ± 0.03 cm 2 s -1 respectively, at 1 atmosphere ( ca . 10 5 Pa) and 294 K, have been obtained. Incidentally to the primary purpose of the experiment, it was observed that the hydrogen atoms spend a small fraction of their time of passage along the tube reversibly adsorbed on its walls. From the measurements, both the partition coefficient, giving the ratio of hydrogen atoms on the walls to those in the gas phase, and the rates of adsorption and desorp­tion can be obtained. This appears to be the first observation of a chromatographic effect for a highly reactive species.


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