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31.
For environmental control purposes, floating oil spills in harbours, off shore areas and their sources must often be identified. Pattern recognition, applied to JR spectrophotometric data (600-2000 cm m 1 range), and to chromatographic data ( n -alkanes) for the spill and various suspected sources such as oil and fuels from ships bunkers and harbour installations, can lead to definite conclusions; particularly after artificial weathering formula are used. The software application provides quick and accurate identification of the pollution source. The identification algorithm has a learning stage in which the user creates a minimal database. This database has a tree structure with classes (fuels, crude, etc.) and members representing samples from already known sources. A sample contains JR and chromatographic data and information of the originating source. A larger database means more knowledge, which conveys a better identification. When the origin of an unknown sample is searched for, the software looks for the best match through the database and displays the results in two lists; sorted by calculated similarity. One list displays the classes in which the unknown sample could be included and the other displays the possible sources. An extra check can be done by visual inspection of the overlapped graphics (unknown sample and each of the identified sources). 相似文献
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The polyfluorinated carboxylic acids 5:3 acid (C5F11CH2CH2CO2H) and 7:3 acid (C7F15CH2CH2CO2H) are major products from 6:2 FTOH (C6F13CH2CH2OH) and 8:2 FTOH (C8F17CH2CH2OH) aerobic biotransformation, respectively. The 5:3 and 7:3 acids were dosed into domestic WWTP activated sludge for 90 d to determine their biodegradability. The 7:3 acid aerobic biodegradability was low, only 1.7 mol% conversion to perfluoroheptanoic acid (PFHpA), whereas no transformation was observed previously in soil. In stark contrast, 5:3 acid aerobic biodegradability was enhanced 10 times in activated sludge compared to soil. The 5:3 acid was not activated by acyl CoEnzyme A (CoA) synthetase, a key step required for further α- or ß-oxidation. Instead, 5:3 acid was directly converted to 4:3 acid (C4F9CH2CH2CO2H, 14.2 mol%) and 3:3 acid (C3F7CH2CH2CO2H, 0.9 mol%) via “one-carbon removal pathways”. The 5:3 acid biotransformation also yielded perfluoropentanoic acid (PFPeA, 5.9 mol%) and perfluorobutanoic acid (PFBA, 0.8 mol%). This is the first report to identify key biotransformation intermediates which demonstrate novel one-carbon removal pathways with sequential removal of CF2 groups. Identified biotransformation intermediates (10.2 mol% in sum) were 5:3 Uacid, α-OH 5:3 acid, 5:2 acid, and 5:2 Uacid. The 5:2 Uacid and 5:2 acid are novel intermediates identified for the first time which confirm the proposed pathways. In the biodegradation pathways, the genesis of the one carbon removal is CO2 elimination from α-OH 5:3 acid. These results suggest that there are enzymatic mechanisms available in the environment that can lead to 6:2 FTOH and 5:3 acid mineralization. The dehydrogenation from 5:3 acid to 5:3 Uacid was the rate-limiting enzymatic step for 5:3 acid conversion to 4:3 acid. 相似文献
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This article presents changes in apparent consumption of steel in Poland in the years 1974–2003. Sudden changes in Polish steel consumption and intensity of steel use in the period of consideration are characteristic of changes in all countries of Central-Eastern Europe. They were tied to a process of transformation from a centrally controlled economy into a market-oriented economy. Particular analyses were made of changes in intensity of steel use in Poland in the years 1992–2003 in sectors of the economy determining the steel consumption. Forecasts for the sector indicators of intensity of steel use were made for the next 5 years. They were utilised in preparing a steel consumption forecast for Poland till the year 2008. The forecast indicates that growth in steel consumption is to be expected from about 8350 thousand tonnes in the year 2003 to about 9520 thousand tonnes in the year 2008. This growth in consumption will accompany a small decrease of the intensity of steel use. For estimation of the regression equations used in the forecast, actual data obtained for the years 1992–2003 was applied. This was a period where the rules of a market economy affected the consumption of steel in Poland. Indicators of steel consumption and also total GDP shares in considered sectors indicated permanent trends of changes over the period. 相似文献
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This paper presents and discusses the results of (239+240)Pu determinations in different components of Gdańsk bay and Gdańsk basin ecosystem, as well as estimated sources and inventories of plutonium in these basins. The total plutonium (239+240)Pu activities deposited in Gdańsk bay and Gdańsk basin sediments are 1.18 TBq and 3.77 TBq, respectively. Two rivers, the Vistula and Neman rivers, and atmospheric fallout were distinguished as the main sources of plutonium in these basins. In seawater (with suspended matter included) there is about 2.33 GBq (239+240)Pu (0.2% of total activity) in Gdańsk bay and 9.92 GBq (239+240)Pu (0.3% of total activity) in Gdańsk basin. In both cases, 56% of (239+240)Pu is associated with suspended matter. Organisms contain 3.81 MBq in Gdańsk bay and 7.45 MBq (239+240)Pu in Gdańsk basin. From this value in Gdańsk bay 82.1% of plutonium is associated with zoobenthos, 13.6% with phytobenthos, 1.6% with phytoplankton, 1.5% with zooplankton and 1.2% with fish. In Gdańsk basin, 83.2% is associated with zoobenthos, 7.5% with phytobenthos, 3.6% with phytoplankton, 3.2% with zooplankton and 2.5% with fish. 相似文献
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Ivascu Larisa Domil Aura Sarfraz Muddassar Bogdan Oana Burca Valentin Pavel Codruta 《Environmental science and pollution research international》2022,29(55):82827-82843
Environmental Science and Pollution Research - The paper examines how environmental, social, and governance (ESG), including management incentives, influence a firm’s financial performance.... 相似文献