Please could you advise me on the following.
For my university dissertation I am looking into the effects of differing rates of sediment supply on river channels and how this effects flooding. To do this I'm using an Armfield flume in the lab and to go along with coarse sediment I need lightweight plastic beads that will be suspended in the mini river system I'm creating. The research counts towards a significant proportion of my final degree. I am using elements from a ground-breaking research paper in USA, which used Urea II Lightweight Plastic Beads (~0.3mm in diameter and a specific gravity of 1.5).
Do you know of any suppliers who could supply this sort of material? Are there any other types of plastic of similar qualities and what sort of price per kg would be expected for this sort of request?