3000 variable speed rotary tool

Experiments to assess emulsion stability in 1:1 water:D₅ emulsions were made (49.5 wt% H₂O, 49.5 wt% D₅, and 1 wt% of the surfactant). The surfactant was measured into a vial and then blended with the appropriate amount of the silicone (D₅) phase, followed by mixing. Then, the water phase was added. To ensure adequate mixing of both phases, a Dremel 3000 Variable Speed Rotary Tool with steel brush was used to mix each vial at 5000 rpm for 10 s. The appearance of the mixtures was noted at various time intervals to determine when the emulsion became unstable. Synthesized compounds were compared with commercial surfactants (Table S1, Supplementary Materials).

A single piece of amber (= burmite) comes from the about 100-million-year old Burmese deposits, Hukawng Valley, Kachin State, Myanmar (Cruickshank & Ko, 2003 (link)). It was bought by Patrick Müller (Käshofen), was part of his private collection under the repository number BUB 2787, and is now deposited in the Staatliche Naturwissenschaftliche Sammlungen Bayerns–Bayerische Staatssammlung für Paläontologie und Geologie in Munich with the collection number SNSB—BSPG 2019 I 171.
The original amber piece was first cut with a Dremel 3000 Variable Speed Rotary Tool. Afterwards it was polished with wet sandpaper, first grade 200 and then subsequently grades 600, 1000 and 5000. Final polishing was performed with Sidol metal polish (Haug, Müller & Haug, 2018 (link)).
Comparative extant material came from the entomological collection of the Centrum für Naturkunde (CeNak), Hamburg. Specimens are registered under the repository numbers ZMH 62827, 62844, 62854 and 62686.