Students

Bc. level: 2020 - 2021
Supervisor: Karol Hensel
Title (en):
Decontamination of respirators by surface dielectric barrier discharge
Title (sk):
Dekontaminácia respirátorov pomocou povrchového dielektrického bariérového výboja
Abstract (en):  hide
The bachelor thesis focuses on surface decontamination of respirators by means of surface dielectric barrier discharge (DBD). In the theoretical part of the work, we discussed the methods of plasma generation using electric discharges, and bio-decontamination effects of plasma in comparison to other conventional methods. We approached the issue of medical waste and focused on an excessive consumption of surgical respiratory masks as a consequence of the pandemic, as well as the impact of respirator waste on the environment and possibilities of its liquidation and decontamination. The main objective of the thesis is to present DBD decontamination of respirators as an effective method of reduction nonrecyclable waste in form of respirators. The experimental part describes series of preliminary tests to demonstrate a decontamination effect of DBD on E. coli bacteria deposited on the surface of the respirators. The DBD system consisted of a pair of electrodes encapsulated inside a dielectric material generating a plasma in a thin layer on the surface. The sample consisted of a piece of a contaminated mask and was repetitively moved trough the plasma zone. The decontamination effect of plasma was investigated at a constant value of applied voltage (2 kV, 30 kHz), while the variable factor was a processing time of the sample (15 – 300 s). After the plasma treatment, the samples were eluted in deionized water and spread on agar in Petri dish and for 20 h cultivated in an incubator. The results of the experiment were evaluated based on the number of bacterial colonies grown on Petri dishes. The results of the experiments showed that 60 s plasma treatment of a sample is sufficient to reduce the population of E. coli by 2,7 log. In case of 180 s plasma treatment 4 log reduction was achieved and we considered this effect and processing time as the optimal.
Abstract (sk)

MSc. level: 2021 - 2023
Supervisor: Karol Hensel
Consultant: Richard Cimerman
Title (en):
Surface discharge in perforated ceramics
Title (sk):
Povrchový výboj v perforovaných keramikách
Abstract (en)
Abstract (sk)