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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Profiling of Mars Atmospheric Carbon Dioxide Isotopologues Using 2-Micron Orbiting Lidar

Mars atmospheric characterization is important for investigating the planet climate history and planning future missions. A feasibility study for implementing the 2-um lidar technology for measuring Martian atmospheric carbon dioxide isotopologues is presented in this paper. Instrument reconfigurations include transmitted wavelengths and detection for differential absorption lidar application using an orbiter platform. Spectral analysis focused on the major four carbon dioxide isotopologues using the 2035 nm wavelength range, which results in minimal interference from other molecular species. Lidar simulation indicated the capability of detecting 12C16O2, 13C16O2, and 18O12C16O near surface vertical profiles up to 20 km altitude. Sensing of 17O12C16O isotopologue is challenging due to lower abundance and Martian atmospheric dust. This orbiting lidar provides a valuable tool for future Mars missions.

Tamer F. Refaat↗
NASA NTRSDate not supplied

Redesign of Carbon Dioxide Removal System for Multifunctional Sorbent Bed Testing

Carbon dioxide removal is a key function of Environmental Control and Life Support System (ECLSS) on the International Space System (ISS). Currently, this system uses pellet beds however they have known issues such as flow channeling and uneven heating. The Multifunction Sorbent (MultiSorb) project is developing 3D-printed zeolite beds with embedded heaters to address these issues. This poster lays out the steps in modifying the Carbon Dioxide Removal and Compression System (CRCS) to test the MultiSorb beds.

MultiSORB↗
NASA NTRSDate not supplied

The Integrated Carbon Dioxide Removal, Compression, andStorage (CRCS) System

The Carbon Dioxide Removal, Compression, and Storage (CRCS) system was designed to remove carbondioxide (CO2(g)) from the spacecraft cabin atmosphere and compress and store the CO2(g) for furtherprocessing. Previous conference papers describe the hardware design and functional testing of the single anddual beds. This paper discusses the integrated system test results when dry CO2(g) latent air (2600ppm CO2(g))enters the system at 30 SCFM.

air revitalization↗
NASA NTRS2022

Diesel Passenger Vehicle Shares Influenced Covid-19 Changes in Urban Nitrogen Dioxide Pollution

Diesel-powered vehicles emit several times more nitrogen oxides than comparable gasoline-powered vehicles, leading to ambient nitrogen dioxide (NO2) pollution and adverse health impacts. The COVID-19 pandemic and ensuing changes in emissions provide a natural experiment to test whether NO2 reductions have been starker in regions of Europe with larger diesel passenger vehicle shares. Here we use a semi-empirical approach that combines in-situ NO2 observations from urban areas and an atmospheric composition model within a machine learning algorithm to estimate business-as-usual NO2 during the first wave of the COVID-19 pandemic in 2020. These estimates account for the moderating influences of meteorology, chemistry, and traffic. Comparing the observed NO2 concentrations against business-as-usual estimates indicates that diesel passenger vehicle shares played a major role in the magnitude of NO2 reductions. European cities with the five largest shares of diesel passenger vehicles experienced NO2 reductions ∼ 2.5 times larger than cities with the five smallest diesel shares. Extending our methods to a cohort of non-European cities reveals that NO2 reductions in these cities were generally smaller than reductions in European cities, which was expected given their small diesel shares. We identify potential factors such as the deterioration of engine controls associated with older diesel vehicles to explain spread in the relationship between cities’ shares of diesel vehicles and changes in NO2 during the pandemic. Our results provide a glimpse of potential NO2 reductions that could accompany future deliberate efforts to phase out or remove passenger vehicles from cities.

Nitrogen Dioxide↗