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In this paper, an investigation of the interaction of a surface-wave-sustained argon plasma torch with liquids is presented. The plasma is produced by an electromagnetic wave traveling along the plasma–dielectric interface, and at the same time, the plasma is a part of this waveguide structure. Because the interaction of the plasma torch with water (liquid) results in modifications of the properties of both the treated water and the plasma itself, a detailed study of the effects in both media is required. The results of the experimental investigation of a surface-wave-sustained argon plasma torch interaction with liquids show significant changes in the plasma parameters, such as the electron excitation temperature Te and the average rotation temperature Trot. In addition, mechanical waves are produced both in the meniscus surface and in the plasma torch by the interaction between the plasma torch (ionized gas with charged particles and electric field) and the liquid surface, which is different from the effects produced by a neutral gas jet on a liquid surface. As a result of the plasma–water interaction, the water’s chemical and physical characteristics, such as the water conductivity, pH, and H2O2 concentration, are modified. As a possible application for water purification, the performed SWD treatment of model wastewater shows a significant variation in nitrate, ammonium, phosphate, and COD (chemical oxygen demand) concentration as a result of the treatment.

Absolute densities of gaseous products generated by coplanar dielectric barrier discharge in N2/O2 mixtures and in ambient air were determined by UV and VIS optical absorption spectroscopy (OAS). Ozone (O3) and nitrogen oxides (N2O, NO2 and N2O5) were identified as the stable products of the discharge. It was found that the actual product composition strongly depends on the gas temperature. At low input power with a low gas temperature, O3 density was high and the NO2 density was very low. When the input power increased and the gas temperature also increased, then O3 disappeared, while NO2 density started to increase steeply., Pomocí UV-VIS spektroskopie byly stanoveny absolutní koncentrace plynných produktů dielektrického koplanárního výboje ve vzduchu a ve směsi N2/O2. Hlavními produkty byly ozon a oxidy dusíku (N2O, NO2 a N2O5), přičemž jejich koncentrace silně závisí na teplotě. Za nízké teploty (nízkého výkonu( dominuje ozon, za vyšších hodnot pak ozon mizí a dominuje NO2.

In recent years, nanoparticles have emerged as an important player in a broad range of applications, especially thanks to recent advances in their synthesis. The silver and copper nanoparticles are often used due to their antibacterial and fungicidal activities, and this article presents the results of the nanoparticle synthesis using electrical glow discharge generated directly in a volume of their salt solutions. Therefore, there is no influence of air (i.e. reactive nitrogen species) as it is usual in other commonly used approaches. Nanoparticles were prepared under various experimental conditions, and they were characterized by ultraviolet/visible spectrometry, dynamic light scattering, X-ray photoelectron spectroscopy, and high-resolution scanning electron microscopy. Particles were produced without any surfactant or stabilizing agent, and some of them showed higher resistance against agglomeration during their short-term (days) storage. The nanoparticle formation mechanism was confirmed by the fast camera imaging. Thus, the developed approach can be applied for simple environmentally friendly nanoparticle production for various applications., IV posledních letech je pozorován prudký nárůst aplikací nanočástic, a to zejména díky progresu v jejich přípravě. Stříbrné a měděné nanočástice jsou často užívány pro svou antimikrobiální a antimykotickou aktivitu. Článek prezentuje syntézu těchto annočástic pomocí plazmatu generovaného přímo ve vodném roztoku anorganických solí, tedy bez přístupu vzduchu. Proces přípravy probíhal za různých podmínek. K charakterizaci nanočástic bylo využito UVS-VIS spektrometrie, dynamického rozptylu světla, rentgenovské fotoelektronové spektormetrie avysoce rozlišující skenovací elektronové mikroskopie. Částice byly připravovány bez použití surfaktantů nebo jiných stabilizačních činidel, a některé z nich nevykazovaly po řadu dní aglomerační tendence. Mechanismus vzniku nanočástic byl potvrzen s využitím snímání vysokorychlostní kamerou. Použitý přístup představuje efektivní a přírodě přátelský postup přípravy kovových nanočástic.

Four different cold plasma sources were directly applied onto a 24h inoculum of Candida glabrata inoculated on agar plates, within the limits of in vitro experiment. Their effects were compared and evaluated with respect to the size and stability of the inhibition zones formed in the posttreatment cultivation. The results prove significant inhibitory cold atmospheric-pressure plasma effects on the yeast C. glabrata. The overall inhibitory effects are directly proportional to the treatment time, the applied power, and the overall functioning of the plasma source and indirectly proportional to the initial cell concentration, although this factor was less significant compared to the other examined factors. The unipolar microwave torch was found to be the most effective in the inhibition of C. glabrata., Čtyři různé zdroje studeného plazmatu byly použity pro přímé ošetření 24hodinového inokula kvasinky Candida glabrata na agarových plotnách, v mezích in vitro experimentu. Jejich účinek byl porovnán a vyhodnocen s ohledem na velikost a stabilitu inhibičních zón vytvořených během kultivace po ošetření. Výsledky potvrdily silný inhibiční vliv studeného atmosférického plazmatu na kvasinku C. glabrata. Celkový inhibiční vliv byl přímo úměrný době ošetření, aplikovanému výkonu a celkové funkčnosti plazmového zdroje, naopak byl nepřímo úměrný počáteční koncentraci buněk, přestože byl tento faktor méně významný oproti ostatním studovaným faktorům. Jako nejvíce účinný zdroj pro inhibici kvasinky C. glabrata byl vyhodnocen mikrovlnný pochodňový výboj.

The objective of this research is to describe the impact of different advanced oxidation processes used for the removal of sulfamethoxazole on wastewater quality. Ozone, UV, a combination of ozone and UV, and plasma discharge were employed. Concentrations of sulfamethoxazole were analysed by LC-MS/MS. Chemical and microbiological analyses and ecotoxicological tests were conducted to investigate the quality of treated wastewater. The results of this study show that the most effective technique for the removal of sulfamethoxazole is O3, followed by plasma discharge, O3 + UV and, finally, UV. A significant effect of tested advanced oxidation processes on the chemical composition of wastewater was not observed; however, the number of microorganisms was reduced. In the case of ecotoxicological tests with Lemna minor and crustacean Daphnia magna, a significant negative effect was only observed when plasma was applied.