Volcanic ash from the eruption of Mount St. Helens on 18 May 1980 fell into Williams Lake in eastern Washington and was temporarily suspended at the sediment-water interface. After several months of compaction, the ash layer broke up and sank into lower density uncompacted lake sediment. Stratigraphic time displacements of several hundred years and a failure to recognize discontinuous ash layer...

The long duration of the 2010 Eyjajallajökull eruption provided a unique opportunity to measure a widely dispersed volcanic ash cloud. Layers of volcanic ash were observed by the European Aerosol Research Lidar Network with a mean depth of 1.2 km and standard deviation of 0.9 km. In this paper we evaluate the ability of the Met Office’s Numerical Atmospheric-dispersion Modelling Environment (NA...

Due to the abundant coal reserves in China, coal is expected to be the most important energy resource in the future. The ash deposition/slagging behavior can obviously affect the heat transfer efficiency of heat transfer tubes in boiler, and cause increasing coal consumption. In order to clarify the effect of ash deposition behavior on heat transfer characteristics of the tube in boiler, a pulv...

Neural networks have recently been widely used to model some of the human activities in many areas of civil engineering applications. In the present paper, artificial neural networks (ANN) for predicting compressive strength of cubes and durability of concrete containing metakaolin with fly ash and silica fume with fly ash are developed at the age of 3, 7, 28, 56 and 90 days. For building these...

Purpose: To carry out phytochemical and physicochemical studies on the leaves of Gynura segetum. Methods: Preliminary phytochemical and physicochemical studies using chromatographic techniques,were carried out, Parameters evaluated include ash value, loss on drying and extractive value, amongst others. . Results: Phytochemical results revealed that the leaves of Gynura segetum contain alkaloid,...

Investigation of the climatic and environmental impacts of the Youngest Toba Tuff (YTT, ∼74 ka BP) eruption of Toba volcano, Sumatra, is crucial for understanding the consequences of the eruption for contemporaneous human populations. The Middle Son Valley, in India, was the first locality on the Indian subcontinent where the YTT was reported. The ash bed forms a discontinuous layer stretching ...

During April and May 2010 the ash cloud from the eruption of the Icelandic volcano Eyjafjallajökull caused widespread disruption to aviation over northern Europe. The location and impact of the eruption led to a wealth of observations of the ash cloud were being obtained which can be used to assess modelling of the long range transport of ash in the troposphere. The UK FAAM (Facility for Airbor...

[1] Granular mass flows of rock fragments are studied in the lab by means of a high-speed video camera at 2000 frames per second. These granular flows are generated using beds of pumice fragments positioned on a rough rotating disk, whose angular velocity is controlled by a motor. The experimental apparatus allows an understanding of the arrangement of the particles in granular mass flows with ...