They used one of these 50 mm diameter blades: https://www.labunlimited.com/s/ALL/4AJ-9197006/IKA-R-1342-Propeller-Stirrers-4-bladed-741000 https://www.labunlim

They used one of these 50 mm diameter blades: https://www.labunlimited.com/s/ALL/4AJ-9197006/IKA-R-1342-Propeller-Stirrers-4-bladed-741000 https://www.labunlimited.com/s/ALL/4AJ-9197006/IKA-R-1342-Pr... Turning at 1000 RPM in a 55 mm diameter 250 mL beaker. Silicone oils, liquid polyesters, and treated vegetable oil were examined. None of their test oils were hydrocarbons. They were trying to form stable aqueous emulsions without using any additives, but some glycerol was involved. Not to mention Nile Red. Meanwhile in the oil business, insane amounts of effort have been made for generations to try and break up these exact kind of emulsions. By using the smallest amount of additives and processing as possible. This property of matter has been extensively studied from an entirely different "angle". Now with samples of major cargoes of crude oil in the analytical laboratory, one of these smaller diameter blades is used in order to fit inside the neck of the official sample bottle: https://www.multilab.ro/foto/ika/eurostar_60_digital.webp https://www.multilab.ro/foto/ika/eurostar_60_digital.webp All the water in the referee sample needs to be thoroughly mixed with the oil before you can withdraw a representative portion to certify the water content of the entire parcel. Different oils have always been recognized as forming emulsions which separate at rates having wildly different orders of magnitude. In the research area it was interesting to pursue the state-of-the-art in emulsion viscosity measurement decades ago, can't find a picture of a Ruska Viscometer but it wasn't good enough anyway, we had to design something completely different in addition. That was an expensive lab to build. With crude oil in particular, you haven't seen nothing until you get a mercury-in-oil emulsion. Behaves like sand.