This paper considers the effect of the discontinuity of electrolyte electrical conductivity on the distribution of potential and protective current density in cathodic protection systems with galvanic anodes. Its aim is to present a simultaneous application of both analytical and numerical models for the calculation of the distribution of protective potential and current density in the cases of homogeneous and double-layer electrolyte. For non-linear boundary conditions at the electrode surface (secondary distribution of protective current density), the indirect boundary element method is used, because of the complexity of calculation for which collocation at the point method was used. The calculation is further complicated due to the nonlinearity of boundary conditions at the electrode surfaces. In order to show the importance of this analysis, calculations for the observed system as well as of errors caused by neglecting the boundary discontinuity of the soil conductivity are provided. Based on these calculations and error analyses, the impact of the double-layer electrolyte on the correct calculation of the cathodic protection system with galvanic anodes is evaluated. This paper also provides the analysis when the double-layered nature of the electrolyte can be practically ignored, which is of great importance to designers of these systems.

The aim of this study was to detect the correlation between the change in the ambient temperature and adaptation of the pronephros – the main haematopoietic organ in fish, which so far has not been subject of research. Compared with other teleosts and their number of blood cells in peripheral blood, tench (Tinca tinca L. 1758) showed the corresponding trend of changes in number of pronephros haematopoietic cells after exposure to increased water temperature. The number of all haematopoietic cell lines was changed during the conditions of thermal stress (P<0.01; P<0.05). The number of erythroblasts was significantly reduced due to shift of haemoglobin curve of dissociation to the right. Leukopoietic cells were increased significantly as a response of pronephros to stress and all endocrine mediators of the stress (cortisol, leukine, etc.). The number of prothrombocytes was slightly decreased due to mobilisation into peripheral blood as in the case of cell precursor of monocytes. Eosinophilic and basophilic granuloblasts were not found in tench pronephros. Correlation (R) between body mass and total length was 0.526. Sex-specific variation of haematopoietic cells number in the same group was not observed (P>0.05), but it was significant between males or females among different groups (P<0.01; P<0.05 respectively).