Abstract: A cold trap is designed to receive an incoming gas mixture and selectively deposit a chemical species on internal walls of the cold trap and exhausting undesired contaminant species from the cold trap. The cold trap includes a thermal control system designed to maintain a deposition temperature on the internal walls to achieve freeze distillation of the chemical species. The cold trap also includes an inlet and/or outlet configured to maintain a pressure in the cold trap to achieve selective deposition of the chemical species into a solid phase without condensing or depositing other chemical species. The thermal control system maintains isothermal conditions on the internal walls while rejecting heat generated in the cold trap to a cold environment outside of the cold trap. In some implementations, the selectively deposited chemical species is water and the cold environment is a lunar environment.

Abstract: This disclosure provides an oxygen delivery and reclamation system that supplies breathable oxygen-enriched gas to one or more users in a chamber. The one or more users receive oxygen at specified oxygen level setpoints. Exhalation air from the one or more users may be purged from the breathing loop using one or both of a recycle pump and an electronically actuated valve. Exhalation air in a purge line and optionally chamber air pulled from the chamber may be recycled using an oxygen concentrator. The oxygen concentrator generates oxygen-enriched gas and oxygen-depleted gas, where the oxygen-enriched gas may be delivered back to one or more users in the chamber.

Abstract: Disclosed herein, among other things, are methods and apparatus for mitigating foreign material buildup for hearing assistance device components. The present subject matter includes a hearing assistance device transducer barrier layer configured to resist accumulation and passage of foreign materials. In various embodiments, the barrier layer includes a membrane that is coated with oleophobic and hydrophobic materials, wherein the barrier is acoustically transparent but prevents the accumulation and passage of unwanted materials.