Papers by Keyword: Contamination

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Authors: Ružena Králiková, Miriam Andrejiová
Abstract: Soil represents a decisive natural resource and economic and eco-social potential of the every country. Soil pollution is one of the biggest environmental problems. Contamination in the soil environment has a significant impact on the use of land resources and can cause high levels of exposure for people living near the site of contamination. Therefore, the risk elements soil pollution assessment is one of the most important resources for comprehensive evaluation of contaminated areas.The paper investigates the degree of heavy metal contamination of agricultural soil in selected Slovakian districts over a monitored period of time. Selected multidimensional statistical methods were applied to analyse and evaluate the degree of soil contamination.
Authors: Y.S. Tan, Simon Y.M. Chooi, Chian-Yuh Sin, Ping-Yu Ee, M.P. Srinivasan, Simo Olavi Pehkonen
Authors: Chun Ming Pei, Ling Li
Abstract: An external insulation of contaminated-insulator assessment method is proposed based on a tri-level data fusion model of combining principal component analysis (PCA) method, artificial neural net (ANN) method and evidence theory in this paper. When contaminated-insulators partial discharge (PD) occur, much effective information obtained from the sound emitted with PD are synthesized to evaluate the external insulation strength of insulators in operation by the studied method. Firstly, nine characteristic parameters that can rapidly reflect the PD process are selected for image-level fusion of PCA to reduce dimension, which gets two new parameters. Then the new parameters are inputted to ANN for feature-level fusion. Finally, the feature-level fusion output is used as the input of decision-level fusion and fused by means of D-S evidence theory for further reducing the uncertainty of assessment. The artificial contamination experiments were explored to verify the proposed method. The result indicates that the proposed model is more precise than the ANN model under the same conditions.
Authors: Michael Otto, Sylvain Rioufrays, Arnaud Favre, Andreas Leibold, Roswitha Altmann, S. Gennaro, R. Dell'Anna, R. Canteri, Lothar Pfitzner
Abstract: The effectiveness of a FOUP (Front Opening Unified Pod) conditioning test bench was tested with respect to the reduction of outgassing materials from FOUP materials and cleanroom compatibility. The equipment uses vacuum and heat to reduce volatile organic compounds from construction material and wafers. Five different analysis methods were used to asses the performance of the equipment with respect to organic, ionic and metal contamination. The experiments showed that the use of heat and vacuum has a positive effect on the organic contamination from FOUPs, and that the equipment is suitable for semiconductor applications in cleanroom environments.
Authors: Jean De Dieu Bazimenyera, Qiang Fu, Niragire Théophila
Abstract: This paper analyzed the effects of land use change in the catchment area of Lake Kivu on its water quality. The results of laboratory analysis of water samples from 4 locations testing the concentration of major elements showed that Mn, N, P and K are high during the growing and raining seasons and low during the dry and harvesting seasons. They also indicated that the concentrations of Cr, Al were considerably low in all seasons but vary with the seasons at Nyamasheke and Karongi stations. The variations of other major elements were not depending on the seasonal variations.
Authors: Joong S. Jeon, Stefan De Gendt, Srini Raghavan, Marcia Almanza-Workman, Cynthia Gonsalves, Bob Ogle
Authors: Twan Bearda, Stefan De Gendt, Lee M. Loewenstein, M. Knotter, Paul W. Mertens, Marc M. Heyns
Authors: F. De Smedt, H. Vankerckhoven, Stefan De Gendt, Marc M. Heyns, Chris Vinckier
Authors: Shu Fen Cheng, Yao Ting Tu, Chin Yuan Huang, Jia Rong Chen, Chi Ying Lai
Abstract: Lead is a common pollutant found in soil. The characteristics of lead contaminated soil may vary depending on various sources of lead pollutants and different soils. In this research, samples were collected from soils contaminated by lead of different sources including discarded slag, lead smelting plant and gunnery firing range for conducting characteristic analyses. The samples were also subject to washing using seven different cleaning agents including acids such as HNO3 and HCl, cationic exchangers such as AlCl3, FeCl3, CaCl2 and MgCl2, as well chelating agent such as EDTA-4Na to study the efficiency of these agents of removing leads of various bindings in the contaminated soil. The results show that he most effective cleaning agents are HNO3, HCl, and EDTA-4Na, FeCl3 and AlCl3 for the exchangeable fraction of lead, HNO3, HCl and FeCl3 for carbonate bond fraction of lead, HNO3, HCl followed by EDTA-4Na and FeCl3 for Fe-Mn oxides bond fraction of lead; HNO3, HCl and FeCl3 for the organic bond fraction lead and HCl for the residual fraction of lead.
Authors: L. Hall, J. Sees, Trace Hurd, B. Schmidt, L. Bellay, Lee M. Loewenstein, Paul W. Mertens
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