Ozone is a major component produced by low-temperature plasmas operating in oxygen-containing gas mixtures. For correlation with biological or clinical results of plasma medical therapies as well as for evaluation of application security, tempo-spatially resolved ozone concentrations need to be considered. When operating a single-electrode dielectric barrier discharge (SE-DBD), the electric field characteristics are dependent on the geometrical setup as well as the electrical properties of the counter electrode. Thus, the counter electrode also affects the plasma input power and hence the total production of chemical species. Therefore, we studied the power input and the tempo-spatial characteristics of ozone concentrations during operation of a SE-DBD operated at voltage pulses in the µs regime against a clean metal electrode and a metal electrode covered with porcine skin samples. At energy densities of up to 1.85 J/cm 2 , the ozone concentrations in the plasma volume amount to as much as 293 ppm whereas at a distance of 5 and 20 cm, respectively, from the discharge, concentrations have decreased beneath recommended safety limits of 0.1 ppm. Furthermore, significantly lower ozone concentrations could be observed when skin samples were used as part of the counter electrode.

Regional spread of mismatch unemployment on the German labour market and conclusions for policies of the Federal Employment Service. A lot of labour market researchers argue that the main problem behind the high unemployment rate in Germany is the mismatch between labour demand and supply. This article, however, shows that such a thesis ignores the spatial dimension and can only be verified for some of the German regions. Labour demand deficiency is at least of equal importance in many other regions. The article identifies which problem is dominant in which region and explains what kind of labour market policies should be therefore preferred respectively.