Recursos de colección

NASA Technical Reports Server (NTRS) (684.608 recursos)

The NTRS is a valuable resource for students, educators, researchers, and the public for access to NASA's current and historical technical literature since it was first released in 1994. NTRS provides access to approximately 500K aerospace related citations, 90K full-text online documents, and 111K images and videos. NTRS numbers continues to grow over time as new scientific and technical information (STI) is created or funded by NASA. The type of information found in NTRS include: conference papers, images, journal articles, photos, meeting papers, movies, patents, research reports, and technical videos.

Mostrando recursos 1 - 20 de 319.980

  1. The U.S. Interagency Volcanic Hazards Sciences and Services Coordination Group

    Murray, John J.
    No abstract available

  2. Lidar Measurements of Atmospheric CO2 From Regional to Global Scales

    Campbell, Joel; Nehrir, Amin; Lin, Bing; Obland, Michael; Fan, Tai-Fang; Kooi, Susan; Browell, Edward; Harrison, F. Wallace; Meadows, Byron; Dobler, Jeremy; Ismail, Syed
    Atmospheric CO2 is a critical forcing for the Earth's climate and the knowledge on its distributions and variations influences predictions of the Earth's future climate. Large uncertainties in the predictions persist due to limited observations. This study uses the airborne Intensity-Modulated Continuous-Wave (IMCW) lidar developed at NASA Langley Research Center to measure regional atmospheric CO2 spatio-temporal variations. Further lidar development and demonstration will provide the capability of global atmospheric CO2 estimations from space, which will significantly advances our knowledge on atmospheric CO2 and reduce the uncertainties in the predictions of future climate. In this presentation, atmospheric CO2 column measurements from...

  3. The Development of a Long-Term, Continually Updated Global Solar Resource at 10 km Resolution: Preliminary Results From Test Processing and Continuing Plans

    Mikovitz, J. Colleen; Sengupta, M.; Schlemmer, J.; Zhang, T.; Perez, R.; Knapp, K.; Stackhouse, P.; Kivalov, S.; Hemker, K.; Cox, Stephen
    Background: Considering the likelihood of global climatic weather pattern changes and the global competition for energy resources, there is an increasing need to provide improved and continuously updated global Earth surface solar resource information. Toward this end, a project was funded under the NASA Applied Science program involving the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC), National Renewable Energy Laboratory (NREL), the State University of New York/Albany (SUNY) and the NOAA National Climatic Data Center (NCDC) to provide NREL with a global long-term advanced global solar mapping production system for improved depiction of historical solar resources and...

  4. Monitoring Changes of Tropical Extreme Rainfall Events Using Differential Absorption Barometric Radar (DiBAR)

    Hu, Yongxiang; Lin, Bing; Lawrence, R. Wes; Min, Qilong; Harrah, Steven
    This work studies the potential of monitoring changes in tropical extreme rainfall events such as tropical storms from space using a Differential-absorption BArometric Radar (DiBAR) operating at 50-55 gigahertz O2 absorption band to remotely measure sea surface air pressure. Air pressure is among the most important variables that affect atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Analyses show that with the proposed radar the errors in instantaneous (averaged) pressure estimates can be as low as approximately 5 millibars (approximately 1 millibar) under all weather conditions. With these sea level pressure measurements, the forecasts,...

  5. 2016 Korea-US Air Quality Study (KORUS-AQ)

    Al-Saadi, Jassim A.
    No abstract available

  6. NASA Earth Observation Systems and Applications for Health and Air Quality

    Omar, Ali H.
    There is a growing body of evidence that the environment can affect human health in ways that are both complex and global in scope. To address some of these complexities, NASA maintains a diverse constellation of Earth observing research satellites, and sponsors research in developing satellite data applications across a wide spectrum of areas. These include environmental health; infectious disease; air quality standards, policies, and regulations; and the impact of climate change on health and air quality in a number of interrelated efforts. The Health and Air Quality Applications fosters the use of observations, modeling systems, forecast development, application integration,...

  7. Deriving Polarization Properties of Desert-Reflected Solar Spectra with PARASOL Data

    Baize, Rosemary R.; Lukashin, Constantine; Sun, Wenbo
    Reflected solar radiation from desert is strongly polarized by sand particles. To date, there is no reliable desert surface reflection model to calculate desert reflection matrix. In this study, the PARASOL data are used to retrieve physical properties of desert. These physical properties are then used in the ADRTM to calculate polarization of desert-reflected light for the whole solar spectra.

  8. Examining HSRL Measurements of Aerosol Optical and Microphysical Properties and Surface PM2.5 During the DISCOVER-AQ Deployments

    Hostetler, Chris; Berkoff, Tim; Anderson, Bruce; Burton, Sharon; Scarino, Amy Jo; Chemyakin, Eduard; Seaman, Shane; Cook, Anthony; Obland, Mike; Hair, John; Müller, Detlef; Fenn, Marta; Rogers, Ray; Ferrare, Richard; Harper, Dave; Beyersdorf, Andreas; Ziemba, Luke
    No abstract available

  9. Improving Climate Projections Using "Intelligent" Ensembles

    Baker, Noel C.; Taylor, Patrick C.
    Recent changes in the climate system have led to growing concern, especially in communities which are highly vulnerable to resource shortages and weather extremes. There is an urgent need for better climate information to develop solutions and strategies for adapting to a changing climate. Climate models provide excellent tools for studying the current state of climate and making future projections. However, these models are subject to biases created by structural uncertainties. Performance metrics-or the systematic determination of model biases-succinctly quantify aspects of climate model behavior. Efforts to standardize climate model experiments and collect simulation data-such as the Coupled Model Intercomparison...

  10. Silicon Valley Air-Taxi Study

    Goodrich, Ken
    No abstract available

  11. Organizational Risk and Opportunity Management: Concepts and Processes for NASA's Consideration

    Dezfuli, Homayoon; Everett, Christopher; Benjamin, Allan
    The focus of this report is on the development of a framework and overall approach that serves the interests of nonprofit and Government organizations like NASA that focus on developing and/or applying new technology (henceforth referred to as organizations like NASA). These interests tend to place emphasis on performing services and achieving scientific and technical gains more than on achieving financial investment goals, which is the province of commercial enterprises. In addition, the objectives of organizations like NASA extend to institutional development and maintenance, financial health, legal and reputational protection, education and partnerships, and mandated milestone achievements. This report discusses...

  12. Flame Retardant Fibers for Human Space Exploration - Past, Present, and Future

    Orndoff, Evelyne
    The National Aeronautics and Space Administration (NASA) has led the development of unique flame retardant fibers for the specific requirements of different space programs. Three of these fibers have greatly contributed to the safety of all the space missions since the Apollo program. Beta alumina-silica microfiber developed for the outer layer of the space suit after the Apollo 1 fire is no longer used and has been replaced by other glass fibers. Expanded polytetrafluoroethylene (e-PTFE) fiber used in the current spacesuit is mostly known today through its trade mark Gore-Tex. Polybenzimidazole (PBI) filament fiber used in many applications from the...

  13. Developing V-Xanes Oxybarometry for Probing Materials Formed in Reducing Environments in the Early Solar Disk

    Jilly-Rehak, C. E.; Westphal, A. J.; Butterworth, A. L.; Righter, K.; Gainsforth, Z.
    Vanadium exhibits four oxidation states (V(sup 2+), V(sup 3+), V(sup 4+) and V(sup 5+)) that have been shown to preferentially partition between melt phases dependent on redox conditions, spanning oxygen fugacity across more than 10 log units. We are developing synchrotron-based x-ray absorption spectroscopy of low-fugacity standards for the determination of V oxidation state in highly reducing conditions relevant to the early solar nebula.

  14. Anionic Pt in Silicate Melts at Low Oxygen Fugacity: Speciation, Partitioning and Implications for Core Formation Processes on Asteroids

    Medard, E.; Martin, A. M.; Malouta, A.; Lee, C.-T.; Righter, K.
    Most siderophile element concentrations in planetary mantles can be explained by metal/ silicate equilibration at high temperature and pressure during core formation. Highly siderophile elements (HSE = Au, Re, and the Pt-group elements), however, usually have higher mantle abundances than predicted by partitioning models, suggesting that their concentrations have been set by late accretion of material that did not equilibrate with the core. The partitioning of HSE at the low oxygen fugacities relevant for core formation is however poorly constrained due to the lack of sufficient experimental constraints to describe the variations of partitioning with key variables like temperature, pressure,...

  15. Effect of Silicon on Activity Coefficients of Platinum in Liquid Fe-Si, With Application to Core Formation

    Righter, K.; Humayun, M.; Pando, K.; Danielson, L. R.
    Earth's core contains approximately 10% of a light element that is likely a combination of S, C, Si, and O, with Si possibly being the most abundant light element. Si dissolved into Fe liquids can have a large effect on the magnitude of the activity coefficient of siderophile elements (SE) in Fe liquids, and thus the partitioning behavior of those elements between core and mantle. The effect of Si can be small such as for Ni and Co, or large such as for Mo, Ge, Sb, As. The effect of Si on many siderophile elements is unknown yet could be...

  16. Open-Loop Flight Testing of COBALT GN&C Technologies for Precise Soft Landing

    Carson, John M., III; Restrepo, Carolina I.; Amzajerdian, Farzin; Seubert, Carl R.
    A terrestrial, open-loop (OL) flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) platform was conducted onboard the Masten Xodiac suborbital rocket testbed, with support through the NASA Advanced Exploration Systems (AES), Game Changing Development (GCD), and Flight Opportunities (FO) Programs. The COBALT platform integrates NASA Guidance, Navigation and Control (GN&C) sensing technologies for autonomous, precise soft landing, including the Navigation Doppler Lidar (NDL) velocity and range sensor and the Lander Vision System (LVS) Terrain Relative Navigation (TRN) system. A specialized navigation filter running onboard COBALT fuzes the NDL and LVS data in real time to...

  17. Surveying Clay Mineral Diversity in the Murray Formation, Gale Crater, Mars

    Vaniman, D. T.; Ming, D. W.; Des Marais, D. J.; Morrison, S. M.; McAdam, A. C.; Chipera, S. J.; Rampe, E. B.; Blake, D. F.; Yen, A. S.; Grotzinger, J. P.; Bristow, T. F.; Morris, R. V.
    One of the primary science goals of Mars Science Laboratory (MSL) is to investigate layered clay mineral-bearing deposits outcropping in the lower NW slopes of Aeolis Mons (Mt. Sharp) detected from orbit. Martian clay mineral-bearing layered rocks are of particular interest because they are potential markers of sedimentary deposits formed in habitable aqueous environments. The CheMin X-ray diffraction (XRD) instrument aboard MSL has documented clay minerals in various drill samples during its traverse of Gale Crater's floor and ascent of Mt. Sharp. Previously, the high concentrations of clay minerals (approximately 20 wt.%) detected in drill powders of mudstone (Sheepbed member)...

  18. The Effect of Shock on the Amorphous Component in Altered Basalt

    Eckley, S. A.; Rampe, E. B.; Wright, S. P.; Niles, P. B.
    Investigation of the geochemical and mineralogical composition of the Martian surface provides insight into the geologic history of the predominantly basaltic crust. The Chemistry and Mineralogy (CheMin) instrument onboard the Curiosity rover has returned the first X-Ray diffraction data from the Martian surface. However, large proportions (27 +/- 14 with some estimates as high as 50 weight percentage) of an amorphous component have been reported. As a remedy to this problem, mass balance equations using geochemistry, volatile chemistry, and mineralogy have been employed to constrain the geochemistry of the amorphous component. However, "the nature and number of amorphous phases that...

  19. Unraveling the Diversity of Early Aqueous Environments and Climate on Mars Through the Phyllosilicate Record

    Gross, C.; Baker, L. L.; Bishop, J. L.; Velbel, M. A.; Michalski, J. R.; Fairén, A. G.; Rampe, E. B.
    Were Martian phyllosilicates formed on the surface or subsurface? Was early Mars warm or cold? How long was liquid water present on the surface of Mars? These are some of the many open questions about our neighboring planet. We propose that the mineralogy of the clay-bearing outcrops on Mars can help address these questions. Abundant phyllosilicates and aqueous minerals are observed nearly everywhere we can see the ancient rocks on Mars. Most bountiful among these is Fe/Mg-smectite. In this study we evaluate the nature and stratigraphy of clay outcrops observed on Mars and the presence of mixtures of other clays...

  20. Mineralogy of Rock Flour in Glaciated Volcanic Terrains: An Analog for a Cold and Icy Early Mars

    Rampe, E. B.; Rutledge, A. M.; Smith, R. J.; Horgan, B.; Scudder, N.
    Geomorphological and mineralogical data from early Martian surfaces indicate liquid water was present on ancient Mars. The relative surface temperatures, however, remain a subject of debate. Was early Mars warm and wet or cold and icy with punctuated periods of warmth and ice melt? By characterizing the mineralogy and geochemistry of modern icy mafic terrains on Earth, we can search for these characteristics in early Martian terrains to better constrain the early Martian climate. Here, we describe the mineralogy of glacial flour in a modern glaciated volcanic terrain in Oregon, USA. We are particularly interested in secondary phases that form...

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