The goal of this paper is to measure the non-wetting to wetting transition temperatures of liquid tin on surfaces of different steel samples in vacuum with residual pressure of 10–8 bar. The experiments were conducted on four steels (C45, S103, CK60 and EN1.4034) of varying compositions using pure tin (99.99%) by the sessile drop method. Non-wetting to wetting transition (contact angle decreasing below 90°) by liquid tin was observed as function of increasing temperature in the range of 820-940 K for low alloyed steels C45, S103 and CK60, while it was considerably higher (around 1130 K) for high chromium EN1.4034 steel. It is concluded that at about the same temperatures, the surfaces of the steel samples are spontaneously deoxidized due to the combined effect of high temperature, low vacuum and C-content of steels. After the oxide layer is removed, the contact angles of liquid tin on steel surfaces were found in the range of 45-80° for low alloyed C45, S103 and CK60 steels and around 20° for high chromium EN1.4034 steel. These relatively high contact angle values compared to other metal/metal couples (such as liquid Cu on steels) are due to the formation of not fully metallic intermetallic compounds (FeSn and FeSn2) at the interface (such do not form in the Cu/Fe system).

The most important factors influencing the human development and health condition are nutrition habits. The quality of food including first of all health safety as well as usable attributes of products often decides about the consumer choice. Safe food should be characterized by both, adequate nutritive value and the tolerably low content of substances which presence could be a risk and threat for health, e.g. pesticide residues. The aim of the study was to estimate long-term and short-term intake of pesticide residues in Polish fruit and vegetables in 2006. The estimation of dietary exposure was based on pesticide residue data from official control of domestic crops carried out by Institute of Plant Protection and on British food consumption data.The estimated dietary intake has shown the chronic dietary exposure of consumers to the pesticide residues in 2006 in Polish crops was relatively low. For fourteen pesticide residues found in apples the long-term intake did not exceed for adult 1.4% and for toddlers 7.6% of the ADI calculated for each compound and respectively 5.1% and 28.3% of the ADI for all compounds total. For eleven residues found in black currants the data were respectively for adult 1.1% and for toddlers 3.3% of the ADI calculated for each compound and 3.3% and 10.3% of the ADI for all compounds total. The long-term exposure values for other 29 commodities were much lower than those for black currant. An acute dietary exposure was estimated for residues of endosulfan in black currants, fenhexamid in raspberries and captan in sour cherries. An acute dietary exposure did not exceed 18.9% for adults and for toddlers 43.2% of the ARfD. The results show that Polish fruit and vegetables are safe in long- as well as in short-term nutrition.