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Effective surface disinfection is crucial for preventing the spread of pathogens in hospitals. Standard UltraViolet-C (UV-C) lamps have been widely used for this purpose, but their disinfection efficiency under real-world conditions is not well understood. To fill this gap, the influence of the power of the ultraviolet radiator, source-sample distance, and exposure time on the performance of UV-C lamps against Escherichia coli and Staphylococcus epidermidis were experimentally determined in the laboratory and hospital. The obtained results showed that the UV irradiance and, thus, the UV-C disinfection efficiency decreased significantly at distances greater than 100 cm from the UV-C lamp. Moreover, increasing the total power of the radiators does not improve the performance of UV-C lamps under real conditions. The UV-C disinfection efficiency greater than 90% was achieved only under laboratory conditions at a close distance from the UV-C lamp, i.e., 10 cm. These findings provide novel insights into the limitations of UV-C lamps in real-world conditions and highlight the need for more effective disinfection strategies in hospitals. [ABSTRACT FROM AUTHOR]

This article presents the methods of processing gold-plated pins from, among others, used computer equipment and discusses the research results on the recovered metal. Due to the relatively small structure of the pins and the fact that the gold layer is only a few microns thick, recovering gold from them constitutes a significant challenge. On the other hand, gold is a precious metal which enables the collective removal of other metals to obtain pure gold. The suggested method involves compacting the gold-plated pins into an anode form and carrying out the electro-refining process. Metals, such as copper, tin and iron, pass into the anode sludge from which they can be extracted or serve as a commercial intermediate sold to smelter plants. The anode sludge was melted in the flame of an oxy-acetylene torch in a graphite crucible by adding borax. As a result of the melting, several metallic precipitates were obtained. Then they were hot-incorporated into a sample with a diameter of 30 mm and a height of 12 mm. Eventually, a pure gold alloy sample was obtained, which contains Cu 40.69%, Sn 9.61% and Au 48.58%. [ABSTRACT FROM AUTHOR]

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