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Number of results: 6
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Abstract

The aim of this study was to examine the pollution level of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and selected chloroorganic pesticides (HCH isomers, DDT and its metabolites, aldrin, dieldrin, endrin, heptachlor, endosulfan I and II, and methoxychlor) in surface sediments from selected fjords, tidal plains and lakes from the North Svalbard area. The sediments were collected from 34 sampling stations in July 2005. Only endosulfan I and methoxychlor, among selected chloroorganic pesticides, were measured in concentrations near detection limit (LoD) in fourteen sediment samples. The sum of seven PCB congeners varied from < 0.9 to 5.6 ng g-1 d.w. in sediments from fjords and tidal plains and from < 0.1 to 14.6 ng g-1 d.w. in sediments from lakes. The concentrations of analysed PAH compounds in surface sediments from lakes were over ten times higher (Ʃ16PAHs to 429 ng g-1 d.w.) than in sediments from fjords and tidal plains (Ʃ16PAHs to 36 ng g-1 d.w.).
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Abstract

Contents of PCBs was investigated using the gas chromatography method in the tissue of four Antarctic migratory birds: Oceanites oceanicus, Larus dominicanus, Catharacta skua and Sterna vittata, and the three penguin species: Pvgoscelis adeliae, P. papua and P. antarctica. Samples were collected at King George Island in February 1978 and, for comparison, in March 1983. The highest PCBs content was recorded in the adipose tissue of O. oceanicus and C. skua (15.7 and 1.2 ppm). Differences in the content of these compounds in the tissue of various penguin species in 1978 was observed. The mean cumulation level of PCBs in the adipose tissue of penguins was higher in 1983 than in 1978. Differences in the level of PCBs contents in the tissue of migratory birds were related to their winter migrations to areas polluted to various degress with PCBs remains. A tendency to the increase of the contamination of penguin tissues with PCBs was observed. This tendency was related to the increase of vhe pollution of the Antarctic environment with these compounds.
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Abstract

The work presents examination results of the common determination of PAHs and PCBs in industrial sludge and supernatants. Sewage sludge was taken from the wastewater treatment plant, and supernatants were obtained by their centrifuging. The prepared samples of sewage sludge and supernatants were subjected to extraction with applying the mixture of organic solvents. Cyclohexane and dichloromethane were used for constant samples, and methanol, cyclohexane and dichloromethane - for liquid. Extracts, after separation from samples of sewage sludge and supernatants, were cleared on the silica gel in vacuum conditions and concentrated in the stream of nitrogen. In such prepared extracts there was conducted the qualitative-quantitative analysis of 16 PAHs using the GC-MS system. Next, the samples were evaporated and poured with water and methanol until the clear solution was obtained. Extracts were cleared on octadecyl C18 columns, and then concentrated in the nitrogen stream. In these extracts PCBs was also determined with the application of the gas chromatograph with mass spectrometer. The range of concentrations 16 PAHs in sewage sludge equalled 10-16 mg/kgd.w. Summary average concentration 16 PAHs in supernatants was reached 17 μg/L. Average recovery of PAHs introduced to sewage sludge in the form of reference mixture was 78% (with consideration of naphthalene). In the case of supernatants, the average value of recovery reached 60%. Average PCBs concentration in supernatants equalled 10 ng/L. For sewage sludge the sum of marked PCBs was an average 1.23 μg/kgd.w.. In the case of particular PCBs the percentage recovery of the reference mixture for supernatants was 86%, while for sewage sludge it was 55%.
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Abstract

The increasing demands for miniaturization and better functionality of electronic components and devices have a significant effect on the requirements facing the printed circuit board (PCB) industry. PCB manufactures are driving for producing high density interconnect (HDI) boards at significantly reduced cost and reduced implementation time. The interconnection complexity of the PCB is still growing and today calls for 50/50 μm or 25/25 μm technology are real. Existing technologies are unable to offer acceptable solution. Recently the Laser Direct Imaging (LDI) technology is considered as an answer for these challenges. LDI is a process of imaging electric circuits directly on PCB without the use of a phototool or mask. Our laboratory system for Laser Direct Imaging is designed for tracks and spaces on PCB with minimum width distance of 50/50 μm. In comparison with conventional photolithography method, this technology is much better for 50/50 μm track and spaces. In our research we used photoresist with resolution 50 μm, but in case of using laser photoresists with better resolution (e.g. 25 μm) it will be possible to image tracks in super-fine-line technology (25/25 μm). The comparison between two technology of creating mosaic pattern tracks on PCB proved that laser imaging is promising technology in high density interconnects patterns, which are widely use in multilayered PCB and similar applications.
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Abstract

The aim of the presented research was to analyse the pollution of the Kozłowa Góra Dam Reservoir with PCBs (28, 52, 101, 118, 138, 153, 180) and heavy metals (Zn, Cu, Ni, Cd, Pb, Cr). The investigated water and bottom sediments were sampled from two sampling points in November, 2009. The sampling points were located in the southern part of the Kozłowa Góra Dam Reservoir. The samples of bottom sediments were taken from the surface layer of 5 cm thickness. The extraction of PCBs from the bottom sediments was performed according to the EPA 3550B standard. For the sequential extraction analysis of metals from the sampled bottom sediments, the method suggested by Tessier was applied. Based on the obtained results the water and bottom sediments from the Kozłowa Góra Dam Reservoir were polluted with polychlorinated biphenyls. The highest concentration of the investigated PCB congeners in bottom sediments was determined in the sampling point No. 1 (2.78 µg/kg d.m.), whereas in the sampling point No. 2 this level was over 20-fold lower which might result from the inflow of these compounds with the waters of the Brynica river. In both sampling points the investigated bottom sediments were predominated by higher chlorinated PCBs with comparable contents of 86% and 85%, respectively. The level of pollution in the investigated bottom sediments (calculated per dry matter) with polychlorinated biphenyls did not exceed the level of TEL (< 0.02 mg/kg). The PEL value (3.5 mg/kg) was exceeded in the case of cadmium in the bottom sediment from the sampling point No. 2 and also lead (91 mg/kg) from both sampling points. The first two fractions with the mobile forms of metals are the most sensitive fractions to any changes of the environmental conditions in the benthic zone. In those fractions significant contents of lead, cadmium, nickel and zinc were observed.
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