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Several advantages are associated with an atmospheric microwave plasma torch, including low cost, easy processing, and high density of electrons and reactive species. This paper develops a compact microwave plasma torch (CMPT) operating at 2.45 GHz with an ultrabandwidth of 30 MHz. The structure and equivalent circuit of CMPT is established and ana...
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... standing-wave ratio (VSWR = Vr/Vin)]. The work flow is shown in Fig. 4. This process is repeated until the MCU steps to the final frequency at which the frequency corresponding to the minimum VSWR no longer changes and the plasma does not grow with the increasement of power anymore. After the last run on searching for frequency is completed, then the whole circuit is stable and size of plasma torch is the ...
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Carbon powders exhibit electrical conductivity that causes the powders to agglomerate due to the applied electrostatic forces and discharges capacitance when used for surface treatments with plasma sources. To avoid this obstacle, a non-direct method is used with active gas that is generated through plasma. This active gas is in contact with the ca...
Citations
... To demonstrate the performance of an MP torch on a quarter-wave coaxial cavity resonator with a solid-state source operating at 2.3-2.5-GHz experiments to modify the surface of polymethyl methacrylate were conducted [11]. MP reactor for diamond deposition on a silicon substrate with a deposition rate of about 3 μm/h at 6 kW was developed [12]. ...
A novel microwave plasma (MP) torch on a rectangular waveguide with two magnetron sources 2.45 GHz and an experimental setup are designed to perform hydroxyapatite (HA) coatings on metallic and dielectric substrates. Operating regimes of a such torch are investigated. Experimental studies have proved the advantages of this method of HA coating in comparison with analogous techniques. The proposed design is suitable for application in other technologies of different materials processing. Results obtained in the present study help to better understand the processes of nano-structural layer formation on solid substrates.
... In this study, microwave plasma, classified as thermal atmospheric plasma, was used as a plasma source. Previous studies have demonstrated that a microwave plasma torch system benefits from the generation of high-density electrons and active species 34,35 . In PAW generated by our microwave plasma system, RNS effectors represented by NO 3 − generated by dissolving NO and NO 2 as primary reactive species were maintained at high concentrations for more than 6 months, even in PAW stored at room temperature. ...
Skin antiseptics have important implications for public health and medicine. Although conventional antiseptics have considerable antimicrobial activity, skin toxicity and the development of resistance are common problems. Plasma-treated water has sterilization and tissue-regenerative effects. Therefore, the aim of this study was to identify whether plasma-activated water (PAW) manufactured by our microwave plasma system can be used as a novel antiseptic solution for skin protection. PAW was produced by dissolving reactive nitrogen oxide gas using microwave plasma in deionized water. The antibacterial effects of PAW against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, and Salmonella typhimurium and effective concentrations were investigated by a solid agar plate assay. The factors mediating the effects of PAW were evaluated by the addition of reactive species scavengers. Cytotoxicity and cell viability assays were performed to examine the protective effect of PAW on normal skin cells. PAW exhibited excellent sterilization and no toxicity in normal skin cells. Experiments also confirmed the potential of PAW as a sanitizer for SARS-CoV-2. Our findings support the use of PAW as an effective skin disinfectant with good safety in the current situation of a global pandemic.
Cold plasma with a glow discharge mechanism is a homogeneous and effective mechanism of nonthermal plasma for industrial applications due to the continuous and stable discharge process compared with the filamentary discharge. The discharge mechanism is essentially dependent upon the input parameters of the plasma system, such as the voltage supply, excitation frequency, and the flow rate of the background gas. This article discusses the effects of input parameters on plasma discharge characteristics produced from the plasma jet reactor. The voltage and supply frequency are tuned to match the discharge gap and background gas flow rate in producing the homogeneous glow plasma discharge. The characteristics of the glow plasma discharge produced were analyzed based on the characteristics of the time–domain discharge current and charge-voltage Lissajous figure techniques. Results show that the most efficient and uniform plasma was disclosed by the configuration of input parameters such as 0.5 kV of the applied voltage, 20 kHz of operating frequency, and 0.8 L/min of purified helium gas flow rate. The single pulse of discharge current and parallelogram-like Lissajous figure obtained indicating the homogeneous plasma discharge with a constant value of discharge capacitance.
