1,760 research outputs found

    Electrochemical Energy Storage Subsystems Study, Volume 2

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    The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models are exercised to define baseline designs and costs. Then the major design and performance parameters are each varied to determine their influence on LCC around the baseline values

    Bridging the Gap Between Scientists and Classrooms: Scientist Engagement in the Expedition Earth and Beyond Program

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    Teachers in today s classrooms need to find creative ways to connect students with science, technology, engineering, mathematics (STEM) experts. These STEM experts can serve as role models and help students think about potential future STEM careers. They can also help reinforce academic knowledge and skills. The cost of transportation restricts teachers ability to take students on field trips exposing them to outside experts and unique learning environments. Additionally, arranging to bring in guest speakers to the classroom seems to happen infrequently, especially in schools in rural areas. The Expedition Earth and Beyond (EEAB) Program [1], facilitated by the Astromaterials Research and Exploration Science (ARES) Directorate Education Program at the NASA Johnson Space Center has created a way to enable teachers to connect their students with STEM experts virtually. These virtual connections not only help engage students with role models, but are also designed to help teachers address concepts and content standards they are required to teach. Through EEAB, scientists are able to actively engage with students across the nation in multiple ways. They can work with student teams as mentors, participate in virtual student team science presentations, or connect with students through Classroom Connection Distance Learning (DL) Events

    Building the Next Generation of Scientific Explorers through Active Engagement with STEM Experts and International Space Station Resources

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    Connecting students and teachers in classrooms with science, technology, engineering, and mathematics (STEM) experts provides an invaluable opportunity for all. These experts can share the benefits and utilization of resources from the International Space Station (ISS) while sharing and "translating" exciting science being conducted by professional scientists. Active engagement with these STEM experts involves students in the journey of science and exploration in an enthralling and understandable manner. This active engagement, connecting classrooms with scientific experts, helps inspire and build the next generation of scientific explorers in academia, private industry, and government

    Expedition Earth and Beyond: Using Crew Earth Observation Imagery from the International Space Station to Facilitate Student-Led Authentic Research

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    Student-led authentic research in the classroom helps motivate students in science, technology, engineering, and mathematics (STEM) related subjects. Classrooms benefit from activities that provide rigor, relevance, and a connection to the real world. Those real world connections are enhanced when they involve meaningful connections with NASA resources and scientists. Using the unique platform of the International Space Station (ISS) and Crew Earth Observation (CEO) imagery, the Expedition Earth and Beyond (EEAB) program provides an exciting way to enable classrooms in grades 5-12 to be active participants in NASA exploration, discovery, and the process of science. EEAB was created by the Astromaterials Research and Exploration Science (ARES) Education Program, at the NASA Johnson Space Center. This Earth and planetary science education program has created a framework enabling students to conduct authentic research about Earth and/or planetary comparisons using the captivating CEO images being taken by astronauts onboard the ISS. The CEO payload has been a science payload onboard the ISS since November 2000. ISS crews are trained in scientific observation of geological, oceanographic, environmental, and meteorological phenomena. Scientists on the ground select and periodically update a series of areas to be photographed as part of the CEO science payload

    Supplement: Going the Distance: Mapping Host Galaxies of LIGO and Virgo Sources in Three Dimensions Using Local Cosmography and Targeted Follow-up

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    This is a supplement to the Letter of Singer et al. (https://arxiv.org/abs/1603.07333), in which we demonstrated a rapid algorithm for obtaining joint 3D estimates of sky location and luminosity distance from observations of binary neutron star mergers with Advanced LIGO and Virgo. We argued that combining the reconstructed volumes with positions and redshifts of possible host galaxies can provide large-aperture but small field of view instruments with a manageable list of targets to search for optical or infrared emission. In this Supplement, we document the new HEALPix-based file format for 3D localizations of gravitational-wave transients. We include Python sample code to show the reader how to perform simple manipulations of the 3D sky maps and extract ranked lists of likely host galaxies. Finally, we include mathematical details of the rapid volume reconstruction algorithm.Comment: For associated data release, see http://asd.gsfc.nasa.gov/Leo.Singer/going-the-distanc

    High-frequency homogenization for periodic media

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    This article is available open access through the publisher’s website at the link below. Copyright @ 2010 The Royal Society.An asymptotic procedure based upon a two-scale approach is developed for wave propagation in a doubly periodic inhomogeneous medium with a characteristic length scale of microstructure far less than that of the macrostructure. In periodic media, there are frequencies for which standing waves, periodic with the period or double period of the cell, on the microscale emerge. These frequencies do not belong to the low-frequency range of validity covered by the classical homogenization theory, which motivates our use of the term ‘high-frequency homogenization’ when perturbing about these standing waves. The resulting long-wave equations are deduced only explicitly dependent upon the macroscale, with the microscale represented by integral quantities. These equations accurately reproduce the behaviour of the Bloch mode spectrum near the edges of the Brillouin zone, hence yielding an explicit way for homogenizing periodic media in the vicinity of ‘cell resonances’. The similarity of such model equations to high-frequency long wavelength asymptotics, for homogeneous acoustic and elastic waveguides, valid in the vicinities of thickness resonances is emphasized. Several illustrative examples are considered and show the efficacy of the developed techniques.NSERC (Canada) and the EPSRC
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