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.

The paper concerns the problem of discontinuity in high pressure die castings (HPDC). The compactness of their structure is not perfect, as

it is sometimes believed. The discontinuities present in these castings are the porosity as follow: shrinkage and gas (hydrogen and gas-air

occlusions) origin. The mixed gas and shrinkage nature of porosity makes it difficult to identify and indicate the dominant source. The

selected parameters of metallurgical quality of AlSi9Cu3 alloy before and after refining and the gravity castings samples (as DI - density

index method), were tested and evaluated. This alloy was served to cast the test casting by HPDC method. The penetrating testing (PT) and

metallographic study of both kinds of castings were realized. The application of the NF&S simulation system allowed virtually to indicate

the porosity zones at risk of a particular type in gravity and high-pressure-die-castings. The comparing of these results with the experiment

allowed to conclude about NF&S models validation. The validity of hypotheses concerning the mechanisms of formation and development

of porosity in HPDC casting were also analyzed.