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A one-dimensional two-phase model of an adsorptive catalytic monolith reactor is used to analyze the Lean NOx Trap (LNT). The model simulates the features of NOx storage and reduction (NSR), a periodic process involving the sequential trapping on a storage component and conversion of NOx to nitrogen on a precious metal catalyst under lean conditions found in the exhaust of lean burn and diesel vehicles. A detailed storage kinetic model is used for the simulations. The NOx storage phase on Pt/BaO/Alumina catalyst has been studied in detail with particular attention to the effect of fluid velocity, storage time and storage component loading. The reductive phase is also analyzed. The simulated results are compared with our lab experimental data. The model predictions are in good agreement with the experimental observations and trends reported in the literature.

Membranes are highly desirable for separating gases in life-support applications. They are small, light, efficient, selective and require little operational or physical maintenance. Facilitated transport membranes have particularly high flux and selectivity. We created enzyme-based facilitated transport membranes using isozymes and mutants as immobilized arrays alone and in conjunction with polymeric membranes. The enzyme operates efficiently at the low CO2 concentrations encountered in respiratory gases and can bring CO2 to near ambient levels. CO2 flux is greatly enhanced and selectivities for CO2 over O2 of 200:1 or greater are possible. The enzymes are robust and stable for long periods under a variety of storage and use conditions.

In preparation for the 21st Century, NASA Johnson Space Center is designing and building a habitat (Bio-Plex) intended for use in long duration missions where all life support systems will be recycled and reused. Crops grown on-board will be used for air and water recycling and also serve as a food source. Space food development for Bio-Plex marks a departure from previous NASA missions yet some basic principles still apply. The differences and similarities will be discussed. The United States space food program has progressed from tubes and cubes in the earlier years to eating familiar food from open containers using normal utensils. All space food development problems include weight and volume restrictions, nutrition, crew acceptability and consumption, and management of food generated waste. To date, food for spaceflight has been carried onboard or delivered in space. Preparation has been limited to rehydration and heating to serving temperature.

Polymer additives in commercial engine oils are mechanically degraded in flows involving large stresses. The oil stability is usually characterized by an asymptotic value called the fully-sheared viscosity. Published data from field and laboratory engine tests show that the kinematic viscosity of degraded oil does not approach such an asymptote. This viscosity reaches a minimum due to the compensating effects of mechanical degradation and oxidation. Kinematic viscosity data from various tests are correlated here using a logarithmic function. This correlation is used to compare the kinetics of degradation processes in different tests. These comparisons suggests that multi-grade oils degrade at a consistent rate in different engine tests. Simulation devices using a diesel fuel injector do not give results comparable to field test data. A milder technique for simulating mechanical degradation of engine oils is suggested to improve correlation with field data.

Fullerenes are spheroidal carbon clusters typically produced by arcing graphite rods in an inert gas such as helium. This process generates structures including C60, C70 and trace amounts of larger clusters. At ambient conditions, these clusters dissolve in a clear 100N bright stock at mass fractions up to 700 ppm. These solutions have a magenta color which is typical of solutions involving aromatic solvents like toluene. Solution density decreases with increasing mass fraction suggesting that fullerenes act like voids in the mineral oil. The low shear rate viscosity exhibits an unusually strong dependence on the volume fraction of fullerenes in solution. This dependence implies an effective diameter that is at least 50% greater than the molecular diameter. These solutions also exhibit abrupt shear thinning from their low rate value to the base stock viscosity. All of these results suggest that aromatic hydrocarbons adsorb onto the fullerene surface.

This research focused on the testing of the original potable water processor aboard Space Station Freedom that was to produce potable water from the humidity condensate and additional water generated by carbon dioxide reduction. Humidity condensate was simulated by an influent water model “Ersatz.” The humidity condensate was treated with multifiltration (MF) beds that consisted of a train of sorption beds (referred to as “Unibed”) designed to remove specific contaminants. For the complete simulated MF system runs tested for 100 bed volumes (BV) (volume processed/total column volume), 0.6% of the TOC was removed by the SAC/IRN 77 (Strong Acid Cation exchange resin), 39.6% of the total organic carbon (TOC) was removed by the WBA/IRA 68 (Weak Base Anion exchange resin), 13.2% of the TOC was removed by activated carbon adsorption (580-26), and the remaining sorbent media acted as polishing units to remove an additional 1.6% of the TOC at steady state.