Rain, a startup building aerial fire-fighting tech, has closed a seed-round of 9.7 million led by DBL partners.

Magrathea, a start-up company located in Oakland, CA, completed its seed round, raising $10 million to make magnesium metal from seawater and brine using an innovative new technology.

Boston-based metals refining company Nth Cycle has closed $44 million in new funding that was supported by several investors, including the Caterpillar Ventures subsidiary of heavy equipment maker Caterpillar Inc.