187 research outputs found

    Setting up of an experimental site for the continuous monitoring of water discharge, suspended sediment transport and groundwater levels in a mediterranean basin. Results of one year of activity

    Get PDF
    The study of suspended sediment transport requires continuous measurement of water discharge to better understand the sediment dynamics. Furthermore, a groundwater monitoring network can support the stream discharge measures, as it reveals how the interactions between surface water and groundwater may affect runoff and consequently sediment transport during flood events. An experimental site for the continuous monitoring of water discharge, suspended sediment transport and groundwater levels was set up in the Carapellotto basin (27.17 km2), which is located in Apulia, Southern Italy. Seven flood events that occurred in the operation timespan were covered with a full record of both water discharge and sediment concentration. Some monitoring problems, largely due to the clogging of the float by mud, suggested to improve the experimental set up. The results show high values of suspended sediments concentration which indicate the sub-basin’s key role in the sediment delivery to the whole river system, while counter-clockwise hysteresis loops are the most frequent due to the basin characteristics. The effects of the interaction between surface water and groundwater are related not only to the flood magnitude but also to the hydrogeological features in the hyporheic zone

    Integrated Assessment of Heavy Metal Contamination in Sediments from a Coastal Industrial Basin, NE China

    Get PDF
    The purpose of this study is to investigate the current status of metal pollution of the sediments from urban-stream, estuary and Jinzhou Bay of the coastal industrial city, NE China. Forty surface sediment samples from river, estuary and bay and one sediment core from Jinzhou bay were collected and analyzed for heavy metal concentrations of Cu, Zn, Pb, Cd, Ni and Mn. The data reveals that there was a remarkable change in the contents of heavy metals among the sampling sediments, and all the mean values of heavy metal concentration were higher than the national guideline values of marine sediment quality of China (GB 18668-2002). This is one of the most polluted of the world’s impacted coastal systems. Both the correlation analyses and geostatistical analyses showed that Cu, Zn, Pb and Cd have a very similar spatial pattern and come from the industrial activities, and the concentration of Mn mainly caused by natural factors. The estuary is the most polluted area with extremely high potential ecological risk; however the contamination decreased with distance seaward of the river estuary. This study clearly highlights the urgent need to make great efforts to control the industrial emission and the exceptionally severe heavy metal pollution in the coastal area, and the immediate measures should be carried out to minimize the rate of contamination, and extent of future pollution problems

    Evaluation of metals that are potentially toxic to agricultural surface soils, using statistical analysis, in northwestern Saudi Arabia

    Get PDF
    © 2015, Springer-Verlag Berlin Heidelberg. Heavy metals in agricultural soils enter the food chain when taken up by plants. The main purpose of this work is to determine metal contamination in agricultural farms in northwestern Saudi Arabia. Fifty surface soil samples were collected from agricultural areas. The study focuses on the geochemical behavior of As, Cd, Co, Cr, Cu, Hg, Pb and Zn, and determines the enrichment factor and geoaccumulation index. Multivariate statistical analysis, including principle component analysis and cluster analysis, is also applied to the acquired data. The study shows considerable variation in the concentrations of the analyzed metals in the studied soil samples. This variation in concentration is attributed to the intensity of agricultural activities and, possibly, to nearby fossil fuel combustion activities, as well as to traffic flows from highways and local roads. Multivariate analysis suggests that As, Cd, Hg and Pb are associated with anthropogenic activities, whereas Co, Cr, Cu and Zn are mainly controlled by geogenic activities. Hg and Pb show the maximum concentration in the analyzed samples as compared to the background concentration

    Nevoid basal cell carcinoma syndrome (Gorlin syndrome)

    Get PDF
    Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is a hereditary condition characterized by a wide range of developmental abnormalities and a predisposition to neoplasms

    Supportive care in patients with advanced non-small-cell lung cancer.

    Get PDF

    Supportive care in patients with advanced non-small-cell lung cancer

    Get PDF

    Brazilian Consensus on Photoprotection

    Full text link
    • …
    corecore