I looked at the variable-throttle version. The slide is at about 09:55 in https://connect.arc.nasa.gov/p1zygzm2h3i/?launcher=false&fcsContent=true&pbMode=normal
It's worse than I thought! They inject Ni nanoparticles into a jet engine as if it were fuel!!! (Presuming you can 'ignite' it, and that you can get heat-transfer to the air.) When it's done its job it just goes out the exhaust. Never mind that nickel nanoparticles are ... a bit toxic?
