The anniversaries of the 1970 Warsaw and the 1990 2+4 Treaties give occasion to revisit the matter of minority protection in German-Polish relations. The interwar system established a problematic unevenness that tainted its acceptance, particularly from the Polish perspective. After 1990 the minority issues achieved an increased, albeit moderate, relevance in German-Polish relations. To some extent the 1991 Polish-German Treaty on Good Neighbourly Relations and Friendly Co-operation retains the unevenness of the inter-war period, as Art. 20(1) recognizes a German minority in Poland, but refuses to acknowledge a Polish minority in Germany. However, currently the thorniest issues concern various situations related to the “Silesians” in Poland, which the Polish government does not recognize as a protected minority under the European Council Framework Convention for the Protection of National Minorities.

The present article is concerned with word formation and word formation exercises. In its theoretical part the article shows the role of word formation in foreign language teaching and learning as well as the state of the art in the research on word formation as a teaching resource. The article further presents the results of an empirical research into the evaluation of word formation practice exercises by learners of German as a foreign language.

The accession of Poland to the European Union involved the need or regional air quality assessment and brought radical change in requirements towards the sottware tools used for assessment purposes. According to Polish law, a zone is an agglomeration o rover 250 000 inhabitants, or a poviat (second level or local government administration in Poland), or a group of poviats, and assessment should consider both global and regional inllow or pollutants as well as the impact of local emission sources and significant sources in a voivodeship. These requirements have imposed a model range of over 250 km. Following an analysis or different models operating all over the world, the CALPUFF model together with the CALMET meteorological processor was chosen to be implemented in air quality assessment systems in Polish zones. This paper presents the results or model calculations performed within the air quality assessment in Mazowieckie voivodeship as well as compares them with the measurements obtained at automatic air monitoring stations.

An LLCL-filter is becoming more attractive than an LCL-filter as the interface between the grid-tied inverter and the grid due to possibility of reducing the copper and the magnetic materials. The efficiency of the LLCL-filter based single-phase grid-tied inverter also excites interests for many applications. The operation of the switches of the VSI is various with different modulation methods, which lead to different efficiencies for such a single-phase grid-tied inverter system, and therefore important research has been carried out on the effect of the choice of PWM schemes. Then power losses and efficiencies of the LLCL-filter and the LCL-filter based single-phase grid-tied inverters are analyzed and compared under the discontinuous unipolar, the dual-buck and the bipolar modulations. Results show that the efficiency of LLCL-filter based inverter system is higher than the LCL- filter based independent on the modulation method adopted. Experiments on a 2 kW prototype are in good agreement with results of the theoretical analysis.