At first glance, shot profile migration and source-receiver (survey-sinking) migration seem to be substantially different algorithms. The basic principles used by the two schemes are different. Shot profile migration is performed by independently propagating the source wavefield and the receiver wavefield. The image is obtained by cross-correlating (possibly normalized by the amplitude of the s...

Biomass and microbial activity in backwashing processes of a biofilter for tertiary treatment were investigated. The microbial groups revealed new distribution along the biofilter depth after low flow rate backwashing for a short time. Then the start-up process was accelerated by backwashing. The biomass profile and microbial activity profile both varying with depth before and after backwashing...

This paper presents positron lifetime studies of the subsurface region of AK12 aluminium alloy and Al2O3-particle-reinforced AK12 aluminium alloy composite after sliding against steel in the pin-on-disc machine. The defect depth profile detected in the AK12 alloy extended up to 300 μm but for the composite AK12 the range of this profile was significantly shortened to less than ∼ 90 μm. The posi...