An increasing number of municipal sewage treatment plants in Poland, desirable from an environmental perspective, raises the problem of managing the growing volume of sewage sludge. The thermal treatment of municipal sewage sludge (TTMSS) method, by greatly reducing the waste volume, increases the heavy metal concentration in fly ash (primary, end product of the treatment process), which may constitute a risk factor when attempting to utilize them economically. The research paper concentrates on determining the TTMSS fly ash heavy metal leaching level. For this purpose, ash samples were subjected to leaching with the batch and percolation tests, and the heavy metal content in eluates was determined by the FAAS method. The obtained results served as a base to determine the level of heavy metal immobilization in the ash, the element release mechanism (percolation test), and the impact of the L/S (liquid to solid) ratio and pH on the heavy metal leaching intensity (percolation test). The conducted research indicated high immobilization of heavy metals in TTMSS fly ash, regardless of the applied study method, which corresponds to the results of other researchers. Lead was the most intensively eluted metal.

The internal diameter of a tube in a ‘church window’ condenser was estimated using an entropy generation minimization approach. The adopted model took into account the entropy generation due to heat transfer and flow resistance from the cooling-water side. Calculations were performed considering two equations for the flow resistance coefficient for four different roughness values of a condenser tube. Following the analysis, the internal diameter of the tube was obtained in the range of 17.5 mm to 20 mm (the current internal diameter of the condenser tube is 22 mm). The calculated diameter depends on and is positively related to the roughness assumed in the model.

This paper presents results of investigations on the application of CuO-water nanofluids for intensification of convective heat transfer. Performance of nanofluids with 2.2 and 4.0 vol.% CuO NPs (nanoparticles) content were examined with regard to heat transfer coefficient and pressure losses in case of turbulent flow in a tube. Negligible impact of examined nanofluid on heat transfer improvement was found. Moreover, measured pressure losses significantly exceeded those determined for primary base liquid. The observations showed that application of nanofluid for heat transfer intensification with a relatively high solid load in the examined flow range is rather controversial.

The research on impact of Cleonus piger Scop. (Coleoptera; Curculionidae) feeding and the occurrence of other pest insects on milk thistle plants grown in monoculture and crop rotation after cereals, with two different seeding dates was carried out in the years 2003–2005. The infestation and density of C. piger larvae in roots of plants grown in monoculture increased with subsequent developmental phases and subsequent years of the experiment. Feeding resulted in the decrease in crop yield by 40% compared to the crop rotation treatment. In crop rotation stands, the infestation of milk thistle roots by C. piger larvae was 4–5 times lower at the final phase than in monoculture. Postponing seeding by three weeks led to the decrease of infestation and density of C. piger larvae, but the crop yield was lower than that from the earlyseeded stands. No other phytophagous species of economic importance were found.

The purpose of the paper is the attempt to point one of the most important aspects of the cultural contact of the Poland and Arabic countries with the consideration of the historical perspective. The author assumes that the language is the basic carrier of such contacts and also the main area of the mutual influences. Therefore, she discusses the Arabic and Polish relations mostly on the level of the translation of the literary and scientific output of both sides, as well as the linguistic interference mainly in the aspect of the lexical borrowings. The author quotes many examples of such linguistic contacts and underlines their great meaning in the existence and development of other types of relations: political, commercial, and cultural.

A draft of the changes to the Polish Academy of Sciences is presented, which will increase its prestige and make better use of the scientific potential of the members of the Academy and the employees of its institutes. The proposed regulations will allow for a comprehensive activation of potential of both institutes and corporate members. The aim of reform is to make the PAS an attractive scientific institution with a focus on the pursuit of fundamental research at the highest level, and to recognize that understanding and clarification of the problem must precede possible applications.