This paper expounds mineral composition, physical and chemical characteristics, activity and its evaluation of natural volcanic ash which is used as concrete admixture.

论述了天然火山灰用作混凝土掺合料的矿物组成、物化性能；火山灰活性及其评定。

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BAE's Simon Shrouder estimates that pilotless aircraft could be used within three to five years to investigate weather systems or natural disasters, such as volcanic ash clouds.

BBC: The Jetstream unmanned aircraft