Environmental Impacts Systematic Analysis of Ports Disposed Dredged Sediments Techniques

2021 ◽  
Vol 21 (2) ◽  
pp. 87-99
Author(s):  
Lorena Novaes Rosa ◽  
Débora Martins de Freitas
Author(s):  
Andri Wibowo

Recently on the December 4, 2021 at 03:00 PM, 3676 m high Mount Semeru located in the East parts of Java Island has erupted. To our best knowledge, an immediate and rapid systematic analysis of the volcanic ash plume courses, PM2.5 emissions, and environmental impacts based on Mount Semeru eruption has not been implemented so far. Then, this research aims to provide and fill the research gap on the rapid assessment of recent Mount Semeru eruption. From the result, it is clearly visible that for 12 hours the volcanic ash plume course was eastward. The volcanic ash plume can travel a distance of 0–10 km to the North and South directions, and more than 10 km to the East direction. The size of the volcanic ash plume was large at 02:00 AM on December 5, 2021. The smallest size of a volcanic ash plume was recorded at 09:00 PM on December 4, 2021. Most parts of the ash plume (55.98%) or equals 39.01 km2 contain fallen volcanic material amounts ranged from 1 kg/m2 to 10 kg/m2. The fallen volcanic material amount peaked between 08:00 PM and 11:00 PM. Based on the estimation, the PM2.5 content in the atmosphere increased after the eruption. The mean of PM2.5 before the eruption was 48.5 ± 19.3(95%CI: 29.2 to 67.8 ug/m3). While after eruption the mean of PM2.5 was 79.4 ± 32.2(95%CI: 47.2 to112 ug/m3). It indicated that the Mount Semeru eruption has increased the PM2.5 equals 63.65%.


Author(s):  
F.J. Sjostrand

In the 1940's and 1950's electron microscopy conferences were attended with everybody interested in learning about the latest technical developments for one very obvious reason. There was the electron microscope with its outstanding performance but nobody could make very much use of it because we were lacking proper techniques to prepare biological specimens. The development of the thin sectioning technique with its perfectioning in 1952 changed the situation and systematic analysis of the structure of cells could now be pursued. Since then electron microscopists have in general become satisfied with the level of resolution at which cellular structures can be analyzed when applying this technique. There has been little interest in trying to push the limit of resolution closer to that determined by the resolving power of the electron microscope.


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