Second grounded electrode non-equilibrium atmospheric pressure argon plasma jet impact on germination of basil (Ocimum basilicum) seeds

In this article, we investigated the impact of a two electrodes argon atmospheric pressure plasma jet with a second grounded electrode (SGE) on the basil (Ocimum basilicum) seeds germination rate. The SGE enhanced the axial electric field in the direction of the treated sample. The plasma operated with two current pulses per each halve a cycle of an applied voltage. The second plasma jet current pulsed increased from 0.7 mA to 3.6 mA and the emission of the O (777.2 nm) increased 3.85 times when the jet operated with the SGE compared to that operated without SGE. The germination rate increased by eight times at 5 min of exposure using the SGE. The SEM images proved a clear etching of the basil (O. basilicum) seed surface by plasma jet with more pronounced etching and cracks by using SGE specially at higher exposure times

Preparation and characterization of sodium dodecyl sulfate/Ag nanoparticles constituting branched microfibers

Branched microfibers of sodium dodecyl sulfate/Ag nanoparticles were synthesized using a nanosecond laser at a wavelength of 532 nm. The synthesis process was investigated at three laser intensities (0.38, 0.76, and 1.53 MW/cm2) and five exposure times (5, 15, 30, 45, and 60 min). At intensities of 0.38 and 0.76 MW/cm2, with increasing the exposure time, the number of nanoparticles increases until an exposure time of 30 min. Above this, exposure saturation of the number of Ag nanoparticles takes place. A similar effect was detected for the size of nanoparticles at these laser intensities. The saturation effect begins at 5 min of exposure for a laser intensity of 1.53 MW/cm2. The estimated nanoparticle size ranges from 116 to 120 nm based on the exposure time for a laser intensity of 0.38 and 0.76 MW/cm2, respectively. Scanning electron microscopy images at low magnification show the branched microfiber structure, while at higher magnifications, nanoparticles of Ag covering these microfibers appear. Electron dispersion x-ray spectroscopy confirmed the presence of Ag. X-ray diffraction results for the particles deposited on a fluorine-doped tin oxide-coated glass substrate were discussed

Susceptibility of Staphylococcus epidermidis to Argon Cold Plasma Jet by Oxygen Admixture

Cold atmospheric pressure sterilization is one of the nominated and efficient techniques to prevent the spread of diseases. Reactive species such as O and OH and other radicals play a major role in the mechanism of plasma sterilization. Therefore, in this work, oxygen was mixed with different parentage from (0.2 to 1.2%) to argon to enhance the generation of the reactive species and increase the argon atmospheric pressure plasma sterilization efficacy. The emission spectra from the jet increase the radicle line intensities by increasing the percentage admixture of O2 with the argon gas to reach a maximum power at 0.8; then, it gradually decreases with a higher O2 percentage. The OH band intensity decreases with increasing the admixture of O2. The jet with different O2 percentages was tested against Gram-positive S. epidermidis, which is the causal agent of nosocomial infections. The maximum reduction in colony-forming units (CFU) was observed at 0.2% O2. No bacterial growth was observed at the later concentration applied for 8 min and the same case was detected at 0.4% O2 applied to 16 min