Abstract Effective biofilm inactivation using a handheld, mobile plasma jet powered by 12 V dc battery and operated in open air without any external gas supply is reported. This cold, room-temperature produced self-repetitive nanosecond discharges with current pulses of ∼100 ns duration, peak amplitude ∼6 mA repetition rate ∼20 kHz. It shown that the reactive species penetrate to bottom layer 25.5 µm-thick Enterococcus faecalis produce strong bactericidal effect. thickest reported...

In this paper, the time and spatially resolved OH distribution of a room-temperature atmospheric-pressure plasma jet is investigated using laser-induced fluorescence (LIF) method. The generated in room air by applying nanosecond pulsed high voltage onto ceramic tube with helium gas flow. It found that, before 'bullet' propagates through region detected laser, there are low LIF signals, which from left previous discharge pulses. After propagation primary (generated at rising edge pulse)...

Abstract We report on factors influencing the specific energy costs of producing NO x from pin-to-pin DC glow discharges in air at atmospheric pressure. Discharge current, gap distance, gas flowrate, exterior tube wall temperature and presence position activated Al 2 O 3 catalyst powder were examined. The heated adjacent to plasma zone improved efficiency by as much 20% low flows, but most efficient conditions found highest flowrates that allowed a stable discharge (about 10–15 l min −1 )....

For room-temperature atmospheric pressure plasma jets (RT-APPJs), because of the gas flow, OH density at a given position is different from case without flow. In this paper, an decay model, which includes main loss processes and flow effect, present. Based on simulation results have very good agreement with behavior measured by laser-induced fluorescence. The absolute RT-APPJ obtained when best fit achieved, about 2.4 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Atmospheric pressure plasma jets (APPJs) have attracted considerable attention over the last decade, specifically for use in surface engineering. A comparative study of an APPJ, driven by pulsed DC voltage, is conducted order to examine impingement onto different surfaces. In this paper, effect gas flow rate and composition investigated using three kinds substrates: dielectric glass, distilled water metal plate fast imaging. Alongside discharges associated with rising falling a so-called...

Real-time diagnostics of cold atmospheric plasma (CAP) sources can be challenging due to the requirement for expensive equipment and complicated analysis. Data analytics that rely on machine learning (ML) methods help address this challenge. In paper, we demonstrate application several ML real-time diagnosis CAPs using information-rich optical emission spectra electro-acoustic emission. We show data based provide a simple effective means estimation operation-relevant parameters such as...

In this work, the dependence of length plasma plume, propagation velocity, electric field in streamer head, and mode transition on tube diameter varied range 0.07–4 mm is investigated for first time. The atmospheric-pressure helium ignited by a positive pulsed direct current voltage with pulse rising time 60 ns, confined inside long glass tube. First, decreased results reduction plume but growth aspect ratio plume. Second, as decreases, average velocity increases first, then reaches maximum...

Plasma plumes with exotically segmented channel structure and plasma bullet propagation are produced in atmospheric jets. This is achieved by tailoring interruptions of a continuous DC power supply over the time scales lifetimes residual electrons preceding discharge phase. These phenomena explained studying dynamics using nanosecond-precision imaging. One 2 – 10 μs 8 kV voltage features still bright from which propagating detaches. A shorter interruption 900 ns produces plume additional...

The production mechanism of OH radicals in a pulsed DC plasma jet is studied by two-dimensional (2-D) model and one-dimensional (1-D) discharge model. For the open air, electron-impact dissociation H2O, electron neutralization H2O+, as well H2O O(1D) are found to be main reactions generate species. contribution more than others. additions N2, O2, into working gas increase density outside tube slightly, which attributed electrons produced Penning ionization. On other hand, O2 inside...

In this paper, first, steady state of the plasma jet at different operating conditions is investigated through Schlieren photography with and without applying shielding gas. Second, dynamic process for impacting on gas flow field studied. When discharge ignited, reduction in laminar occurs. However, when rate too low or high, phenomenon not obvious. What more, both frequency voltage have significant impact effect flow, but former more significant. Shielding provides a curtain to propagate...

Fusarium graminearum (F. graminearum) as the major pathogen for head blight (FHB) in wheat can cause severe yield loss and secrete mycotoxins to contaminate grain. Herein, this study prepared a novel green fungicide named plasma-activated water (PAW) by only using air, electricity via cold plasma activation, investigated its antifungal effects against F. spores. The in-vitro results showed that PAW achieved 1.98 3.98 log reduction of spores treatment times ranging from 30 120 min. also...

In this paper, we investigate the temporally resolved evolution of nanosecond pulsed dielectric barrier discharge (DBD) in a moderate 6 mm gap under various pressures and pulse repetition frequencies (PRFs) by intensified charge-coupled device (ICCD) images, using dry air its components oxygen nitrogen. It is found that are very different when mode transits between uniform filamentary air, oxygen, The PRFs can also obviously affect mode-transition. transition mechanism DBD not...

OH radical is one of the important reactive species generated by non-equilibrium atmospheric-pressure plasma jets, which believed to play an role in medicine applications such as cancer therapy, wound healing and sterilization. In this study, a method increase density proposed. By using multiple pairs ring electrodes, we generate 3–5 times more radicals than common device uses only high-voltage electrode. Discharge imaging shows that plume with electrode longer its emission intensity higher...

Abstract This study presents insights into the use of activated catalysts to improve energy efficiency production in atmospheric pressure air plasma. The introduction direct current glow discharge system reduces cost by up 45% at low gas flow rates. Notably, even when positioned away from plasma zone, catalyst enhanced production, suggesting a significant role for catalytic activation downstream neutral species. also introduced novel approach involving an jet infused with floating powder....

A nonequilibrium plasma jet array is reported in this paper. The gas temperature of the at room temperature. High-speed photographs show that propagation speed each plume not same. At beginning, plumes on both edges higher than middle array. simulation results indicate due to electric-field distribution After 125 ns, behavior looks like glow discharges.

A handheld, battery-operated atmospheric-pressure plasma rod (named the wand) which does not rely on an external power source (e.g. mains or a generator) gas supply is reported. The wand can be used for killing bacteria, fungi viruses that are hidden in narrow channels such as nasal cavity and ear canal, difficult to access using most currently available devices. Besides, electrical characterization, temperature, emission spectra of plasma, ozone OH radical concentration generated by device,...

The different discharge modes that were observed for a plasma jet operated at atmospheric pressure with air or nitrogen by applying DC high voltage to microhollow cathode geometry investigated. Critical parameters determine the operation in either self-pulsing 'true' mode identified based on an electrical circuit model and investigated accordingly. Current limitation overall resistance supports continuous charging discharging of stray capacities, together associated repetitive generation,...

ABSTRACT A Magnetic Field Stabilized Glow Discharge (MSGD) device is used to perform nitrogen fixation (NF) and CO 2 conversion at atmospheric pressure using N ‐CO air‐CO gas mixtures. It found that for mixtures, the concentration increases with volume fraction, reaching a maximum of 56 198 ppm 100% , corresponding energy cost lowest 0.61 MJ/mol, while efficiency reaches its highest 46.7%. For discharge, NF (11.24 MJ/mol) occurs ratio approximately 1:1 (N : ), NO x 2968 ppm. (2.59 achieved...

The overhead contact system of the electrification railway is exposed to natural environment throughout year and liable encounter problem line icing. icing on will reduce current-collection performance pantograph, resulting in a decrease safety reliability system. It an effective way solve by using Joule heat generated DC conductor melt ice. In this paper, multi-physics simulation software COMSOL used construct finite element model unit composed line, catenary wire dropper. covers physical...

Abstract A pulse-modulated microwave air discharge operating at 2.475 GHz was applied for the conversion of nitrogen (N₂) and oxygen (O₂) into oxides (NOₓ), including NO, NO₂, N₂O₄. The effects pulse modulation frequency, duty cycle, flow rate, O₂ content were investigated better understanding optimization NOₓ productivity corresponding energy cost (EC). results indicated that high-frequency pulses (10 kHz – 100 kHz) had a minimal effect on consumption However, cycle significantly influenced...