Browsing by Author "Lee, Jeffrey M."
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Item An Equivalent System Mass (ESM) Analysis for the Universal Waste Management System (UWMS) with and without the Torrefaction Processing Unit (TPU)(2020 International Conference on Environmental Systems, 2020-07-31) Wójtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Lee, Jeffrey M.Equivalent System Mass (EMS) is one of the metrics commonly used in the evaluation of new systems, often performed as part of trade studies. ESM is a technique that makes it possible to reduce several physical quantities describing a system, or a subsystem, to a single parameter expressed in the units of mass. ESM has the following five components: (1) mass; (2) volume; (3) power; (4) cooling; and (5) crewtime. In this paper, results of an ESM analysis are reported for the Torrefaction Processing Unit (TPU) and the Metabolic Solid Waste Storage (MSWS), both considered in conjunction with the Universal Waste Management System (UWMS). The TPU involves sterilization of human solid waste via mild non-oxidative thermal treatment (torrefaction) to produce a stable, relatively odor-free solid product. This product can be easily stored, or recycled, and TPU operation is associated with the simultaneous water recovery from the solid waste. The TPU is designed to be compatible with the UWMS, now under development by NASA. In contrast to the TPU, the MSWS involves no waste processing, which results in the need to store large amounts of unprocessed solid waste. A stand-alone TPU could be used to treat the contents of a waste canister from the UWMS, thus allowing the waste canister to be reused, which significantly reduces the number of canisters required on board. An ESM analysis was performed for the TPU and for the MSWS, and results were compared for the case of a Mars mission and a four-person crew. Results show that the use of the TPU is associated with some advantages as compared with the MSWS, even though system design is more complex.Item An Examination of Trash Ozonation(44th International Conference on Environmental Systems, 2014-07-13) Lee, Jeffrey M.; Fisher, John W.; Harris, Linden C.; Wignarajah, Kanapathipillai; Alba, Richard G.We report on the potential for using dissolved ozone in water – ozonation – to oxidize trash and waste. An SBIR Phase II pilot scale ozonation system developed by TDA Research, Inc. was tested for use in oxidizing various mixtures of trash and wastes that included plastics, foodstuff, packaging, cloth, paper, fecal simulant, and pre-processed Heat Melt Compactor tiles. In addition to pure liquid phase ozonation, we also modified and tested the system for gas phase ozone oxidation in saturated water vapor with a heating element to promote smoldering. These tests were conducted as part of the NASA “Trash to Gas” project to identify candidate technologies for processing low value trash and waste into higher value product gasses.Item A Method for Capturing, Tracking and Ranking the Relative Competitiveness of Competing Alternatives(44th International Conference on Environmental Systems, 2014-07-13) Lee, Jeffrey M.An “old” and “new” method for ranking competing alternatives by capturing and tracking success criteria at the requirements level is proposed. The established old method of Quality Function Deployment (QFD) is reviewed and examined within the context of capturing customer and functional requirements, and cross correlating those requirements within a weighted scoring system. This provides a common frame of reference for comparing system solutions. Complementing the established method is the newly proposed OPU$ that uses prediction markets to track and forecast the relative competitiveness between solutions. This is done through market pricing of real options written on functional requirements that are directly traceable to product technical characteristics and user needs. The combination of QFD and OPU$ allows visibility, clarity, and continuous tracking of success criteria, and reveals the relative competitiveness of solution choices.