The Orontes river basin can be considered one of the most polluted areas in the eastern Mediterranean due to the intense urban occupation, intensive agriculture irrigation, and large numbers of different industries ac...The Orontes river basin can be considered one of the most polluted areas in the eastern Mediterranean due to the intense urban occupation, intensive agriculture irrigation, and large numbers of different industries activities. The objective of the study was to assess the extent and severity of heavy metal pollution of arable soils of Hama floodplain, in order to provide a general insight vision of pollution status in this intensive agricultural production area. The present and spatial distribution of four heavy metals (Cd, Cu, Pb, Zn) concentration have been examined in 5 monitoring sites of river’s water along the part of the river passing through the plain of Hama;and also from 93 samples of topsoil from the area surrounding the city of Hama have been examined. The concentrations of heavy metals in both river water and soil were within the international standards. Water analyses indicated pH of moderately alkaline, no irrigation problem related to ammonium nitrogen and phosphate phosphorus, while the Electrical Conductivity (EC) has referred to an increasing problem. Geo-accumulation Index (Igeo) refers to strong building up for Cd, Pb, and very strongly for Cu. Soil analyses refer to clayey, calcareous, and alkaline soil with pH ranges from 7.5 to 8.6, with significantly higher organic matter content especially near sewage plants, attributed to irrigation with untreated sewage sludge water. Geostatistical analysis of data showed up normal spatial distribution related to the high variation between the values of the studied elements;whereas the Cu and Cd concentrations were higher than allowable limit near the steel, rubber wheel factories and reach 127 for Cu and 9.8 μg·g-1 for Cd. Additionally, a high concentration of Cu was significantly associated with organic matter content. The concentration of Pb was within the limits, with the exception of riverbanks where the values of Pb exceed 95 μg·g-1, with (Igeo) of 4.22 refers strongly to very strong accumulation. Total Zn concentration showed higher variability and values ranging from 13 to 760 μg·g-1, with a distribution trend increases from southeast to northwest. However, its environmental risk will be more serious to human and livestock.展开更多
New strategies and methods for assessing the security of protection systems to reduce the risk of unnecessary disturbances and blackouts are the main topic of the present paper. The system behavior of a protection sys...New strategies and methods for assessing the security of protection systems to reduce the risk of unnecessary disturbances and blackouts are the main topic of the present paper. The system behavior of a protection system and network is analyzed and assessed as a whole. Hence, the established algorithms are capable to handle complex network structures with regard to an intelligent data management as well as data validation. Protection security assessment comprised two different aspects: on the one hand the behavior regarding dependability and security in terms of speed and sensitivity, on the other hand the behavior regarding the response on dynamic network phenomena as voltage stability and transient stability. A new automated method for assessing the dependability and security of protection systems is shown. The short-circuit simulation tool is used to provide a simulation system including network and protection devices as a whole. The handling of the large amount of resulting data is done by an intelligent visualization method like a “fingerprint” analysis. Further on the paper is focused on the protection response on dynamic network phenomena and presents innovative strategies for this investigation aspect. The structure of simulation environment will be described. Results of a case study show the application of this method on a real network. The system tool which is concluding these two aspects of protection assessment is called SIGUARD? PSA.展开更多
文摘The Orontes river basin can be considered one of the most polluted areas in the eastern Mediterranean due to the intense urban occupation, intensive agriculture irrigation, and large numbers of different industries activities. The objective of the study was to assess the extent and severity of heavy metal pollution of arable soils of Hama floodplain, in order to provide a general insight vision of pollution status in this intensive agricultural production area. The present and spatial distribution of four heavy metals (Cd, Cu, Pb, Zn) concentration have been examined in 5 monitoring sites of river’s water along the part of the river passing through the plain of Hama;and also from 93 samples of topsoil from the area surrounding the city of Hama have been examined. The concentrations of heavy metals in both river water and soil were within the international standards. Water analyses indicated pH of moderately alkaline, no irrigation problem related to ammonium nitrogen and phosphate phosphorus, while the Electrical Conductivity (EC) has referred to an increasing problem. Geo-accumulation Index (Igeo) refers to strong building up for Cd, Pb, and very strongly for Cu. Soil analyses refer to clayey, calcareous, and alkaline soil with pH ranges from 7.5 to 8.6, with significantly higher organic matter content especially near sewage plants, attributed to irrigation with untreated sewage sludge water. Geostatistical analysis of data showed up normal spatial distribution related to the high variation between the values of the studied elements;whereas the Cu and Cd concentrations were higher than allowable limit near the steel, rubber wheel factories and reach 127 for Cu and 9.8 μg·g-1 for Cd. Additionally, a high concentration of Cu was significantly associated with organic matter content. The concentration of Pb was within the limits, with the exception of riverbanks where the values of Pb exceed 95 μg·g-1, with (Igeo) of 4.22 refers strongly to very strong accumulation. Total Zn concentration showed higher variability and values ranging from 13 to 760 μg·g-1, with a distribution trend increases from southeast to northwest. However, its environmental risk will be more serious to human and livestock.
文摘New strategies and methods for assessing the security of protection systems to reduce the risk of unnecessary disturbances and blackouts are the main topic of the present paper. The system behavior of a protection system and network is analyzed and assessed as a whole. Hence, the established algorithms are capable to handle complex network structures with regard to an intelligent data management as well as data validation. Protection security assessment comprised two different aspects: on the one hand the behavior regarding dependability and security in terms of speed and sensitivity, on the other hand the behavior regarding the response on dynamic network phenomena as voltage stability and transient stability. A new automated method for assessing the dependability and security of protection systems is shown. The short-circuit simulation tool is used to provide a simulation system including network and protection devices as a whole. The handling of the large amount of resulting data is done by an intelligent visualization method like a “fingerprint” analysis. Further on the paper is focused on the protection response on dynamic network phenomena and presents innovative strategies for this investigation aspect. The structure of simulation environment will be described. Results of a case study show the application of this method on a real network. The system tool which is concluding these two aspects of protection assessment is called SIGUARD? PSA.
