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  • Astronomy  (1,062)
  • Fluid Mechanics and Thermodynamics  (710)
  • Engineering
  • 2005-2009  (1,830)
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Year
  • 1
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Condensed matter ; Engineering ; Magnetism ; Materials ; Nanotechnology
    ISBN: 9783540495765
    Language: English
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  • 2
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    Berlin, Heidelberg : Springer
    Keywords: Electronics ; Engineering ; Optical materials ; Physical optics
    ISBN: 9783540718925
    Language: English
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  • 3
    Keywords: Condensed matter ; Engineering ; Optical materials
    ISBN: 9783540734567
    Language: English
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  • 4
    Keywords: Electronics ; Engineering ; Nanotechnology ; Thermodynamics
    ISBN: 9783540736073
    Language: English
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  • 5
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Crystallography ; Engineering ; Particles (Nuclear physics) ; Surfaces (Physics)
    Edition: Third Edition
    ISBN: 9783540738862
    Language: English
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  • 6
    Keywords: Condensed matter ; Engineering ; Engineering design ; Materials ; Physics
    ISBN: 9780387345659
    Language: English
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  • 7
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    Boston, MA : Springer US
    Keywords: Chemistry ; Engineering ; Materials ; Mechanical engineering ; Surfaces (Physics)
    ISBN: 9780387476858
    Language: English
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  • 8
    Keywords: Astronomy ; Cardiology ; Chemistry, Physical organic ; Nuclear chemistry ; Radiology, Medical
    ISBN: 9781402023781
    Language: English
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  • 9
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    Berlin, Heidelberg : Springer
    Keywords: Condensed matter ; Engineering ; Optical materials ; Surfaces (Physics)
    ISBN: 9783540264620
    Language: English
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  • 10
    Keywords: Electronics ; Engineering ; Nanotechnology ; Optical materials ; System safety
    ISBN: 9783540269458
    Language: English
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  • 11
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    Berlin, Heidelberg : Springer
    Keywords: Computer engineering ; Engineering ; Nanotechnology ; Optical materials ; Physical optics ; Quantum optics
    ISBN: 9783540469360
    Language: English
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  • 12
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    Berlin, Heidelberg : Springer
    Keywords: Condensed matter ; Engineering ; Materials ; Nanotechnology ; Optical materials
    ISBN: 9783540401865
    Language: English
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  • 13
    Keywords: Building construction ; Engineering ; Materials ; Physics
    ISBN: 9781852334277
    Language: English
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  • 14
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    Berlin, Heidelberg : Springer
    Keywords: Analytical biochemistry ; Biotechnology ; Engineering ; Food science ; Medical laboratories
    ISBN: 9783540457435
    Language: English
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  • 15
    Keywords: Engineering ; Laser physics ; Microwaves ; Optical materials ; Physical optics
    ISBN: 9780387686172
    Language: English
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  • 16
    Keywords: Chemistry, Physical organic ; Chemistry, inorganic ; Condensed matter ; Engineering ; Materials ; Structural control (Engineering)
    ISBN: 9781402034718
    Language: English
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  • 17
    Keywords: Engineering ; Materials ; Materials ; Materials ; Mechanics ; Nuclear engineering
    ISBN: 9781402053290
    Language: English
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  • 18
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Chemistry, Physical organic ; Condensed matter ; Engineering ; Optical materials
    ISBN: 9783540712954
    Language: English
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  • 19
    Keywords: Condensed matter ; Engineering ; Materials ; Nanotechnology ; Optical materials
    ISBN: 9781402035623
    Language: English
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  • 20
    Keywords: Electromagnetism ; Engineering ; Laser physics ; Remote sensing
    ISBN: 9781402065033
    Language: English
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  • 21
    Keywords: Astronomy ; Chemistry, Physical organic ; Geochemistry ; Life sciences ; Planetology ; Plasma (Ionized gases)
    ISBN: 9781402041358
    Language: English
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  • 22
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Electronics ; Engineering ; Nanotechnology
    ISBN: 9783540283089
    Language: English
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  • 23
    Keywords: Biochemistry ; Chemistry, Physical organic ; Engineering ; Life sciences ; Nanotechnology ; Physical optics
    ISBN: 9783540284727
    Language: English
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  • 24
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    Berlin, Heidelberg : Springer
    Keywords: Chemistry ; Mathematics ; Engineering ; Operations research ; Systems theory
    ISBN: 9783540488804
    Language: English
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  • 25
    Keywords: Chemistry, Physical organic ; Engineering ; Nanotechnology ; Optical materials ; Physics
    ISBN: 9783540687528
    Language: English
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  • 26
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    Boston, MA : Springer
    Keywords: Engineering ; Machinery ; Materials
    ISBN: 9780387725284
    Language: English
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  • 27
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    New York, NY : Springer
    Keywords: Engineering ; Optical materials ; Physical optics
    ISBN: 9780387748016
    Language: English
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  • 28
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    Totowa, NJ : Humana Press
    Keywords: Biochemical engineering ; Biotechnology ; Chemical engineering ; Engineering ; Environmental sciences ; Microbiology
    ISBN: 9781592599967
    Language: English
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  • 29
    Keywords: Chemistry ; Engineering ; Magnetism ; Materials ; Optical materials
    ISBN: 9781402087967
    Language: English
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  • 30
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Condensed matter ; Engineering ; Nanotechnology
    ISBN: 9783540726753
    Language: English
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  • 31
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    Berlin, Heidelberg : Springer
    Keywords: Engineering ; Nanotechnology ; Particles (Nuclear physics)
    ISBN: 9783540745570
    Language: English
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  • 32
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    Berlin, Heidelberg : Springer
    Keywords: Engineering ; Magnetism ; Nanotechnology ; Optical materials
    ISBN: 9783540493365
    Language: English
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  • 33
    Keywords: Engineering ; Materials
    ISBN: 9781402085840
    Language: English
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  • 34
    Keywords: Electronics ; Engineering ; Optical materials ; Spectrum analysis
    ISBN: 9783540274124
    Language: English
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  • 35
    Keywords: Computer science ; Engineering ; Materials ; Nuclear engineering ; Thermodynamics
    ISBN: 9781402084225
    Language: English
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  • 36
    Keywords: Engineering ; Optical materials ; Physical optics
    ISBN: 9781402084256
    Language: English
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  • 37
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    Berlin, Heidelberg : Springer
    Keywords: Condensed matter ; Engineering ; Nanotechnology
    ISBN: 9783540375784
    Language: English
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  • 38
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Analytical biochemistry ; Chemistry ; Chemistry, Physical organic ; Engineering
    ISBN: 9783540745983
    Language: English
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  • 39
    Unknown
    Dordrecht : Springer
    Keywords: Chemicals ; Safety measures ; Engineering ; Materials ; Polymers
    ISBN: 9781402053566
    Language: English
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  • 40
    Keywords: Condensed matter ; Engineering ; Materials ; Nanotechnology ; Optical materials
    ISBN: 9781402089039
    Language: English
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  • 41
    Keywords: Chemistry, inorganic ; Engineering ; Materials
    ISBN: 9783540687580
    Language: English
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  • 42
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Chemistry, Physical organic ; Engineering ; Nanotechnology ; Surfaces (Physics)
    ISBN: 9783540745518
    Language: English
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  • 43
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Condensed matter ; Engineering ; Nanotechnology ; Surfaces (Physics)
    ISBN: 9783540343158
    Language: English
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  • 44
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Chemistry, inorganic ; Condensed matter ; Engineering ; Nanotechnology ; Surfaces (Physics)
    ISBN: 9783540368076
    Language: English
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  • 45
    Keywords: Engineering ; Optical materials ; Particles (Nuclear physics) ; Physical optics ; Polymers
    ISBN: 9783540719236
    Language: English
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  • 46
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Engineering ; Optical materials ; Particles (Nuclear physics) ; Physical optics
    ISBN: 9783540745297
    Language: English
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  • 47
    Unknown
    Boston, MA : Kluwer Academic Publishers
    Keywords: Engineering ; Materials
    ISBN: 9781402081330
    Language: English
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  • 48
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    Nature Publishing Group (NPG)
    Publication Date: 2008-10-10
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dennis, Carina -- England -- Nature. 2008 Oct 9;455(7214):716. doi: 10.1038/455716a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18843326" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; Australia ; Science/*organization & administration/trends ; Sex Factors ; Stem Cells
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 49
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    Nature Publishing Group (NPG)
    Publication Date: 2008-12-30
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schiermeier, Quirin -- England -- Nature. 2008 Nov 27;456(7221):540-1. doi: 10.1038/nj7221-540a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19112617" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Conservation of Natural Resources/trends ; *Ecosystem ; Employment/statistics & numerical data ; Engineering ; Greenhouse Effect ; Industry/manpower ; Marine Biology/manpower/trends ; Oceanography/education/*manpower/*trends ; Oceans and Seas ; Petroleum ; Physics
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 50
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    Nature Publishing Group (NPG)
    Publication Date: 2008-09-19
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ball, Philip -- England -- Nature. 2008 Sep 18;455(7211):274-5. doi: 10.1038/455274a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18800099" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; *Bibliometrics ; Peer Review, Research/standards ; Publishing/*statistics & numerical data ; Research/*statistics & numerical data ; Time Factors
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 51
    Publication Date: 2009-01-06
    Description: Self-gravity plays a decisive role in the final stages of star formation, where dense cores (size approximately 0.1 parsecs) inside molecular clouds collapse to form star-plus-disk systems. But self-gravity's role at earlier times (and on larger length scales, such as approximately 1 parsec) is unclear; some molecular cloud simulations that do not include self-gravity suggest that 'turbulent fragmentation' alone is sufficient to create a mass distribution of dense cores that resembles, and sets, the stellar initial mass function. Here we report a 'dendrogram' (hierarchical tree-diagram) analysis that reveals that self-gravity plays a significant role over the full range of possible scales traced by (13)CO observations in the L1448 molecular cloud, but not everywhere in the observed region. In particular, more than 90 per cent of the compact 'pre-stellar cores' traced by peaks of dust emission are projected on the sky within one of the dendrogram's self-gravitating 'leaves'. As these peaks mark the locations of already-forming stars, or of those probably about to form, a self-gravitating cocoon seems a critical condition for their existence. Turbulent fragmentation simulations without self-gravity-even of unmagnetized isothermal material-can yield mass and velocity power spectra very similar to what is observed in clouds like L1448. But a dendrogram of such a simulation shows that nearly all the gas in it (much more than in the observations) appears to be self-gravitating. A potentially significant role for gravity in 'non-self-gravitating' simulations suggests inconsistency in simulation assumptions and output, and that it is necessary to include self-gravity in any realistic simulation of the star-formation process on subparsec scales.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3817203/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3817203/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Goodman, Alyssa A -- Rosolowsky, Erik W -- Borkin, Michelle A -- Foster, Jonathan B -- Halle, Michael -- Kauffmann, Jens -- Pineda, Jaime E -- P41 RR013218/RR/NCRR NIH HHS/ -- P41 RR013218-12/RR/NCRR NIH HHS/ -- U54 EB005149/EB/NIBIB NIH HHS/ -- U54 EB005149-05/EB/NIBIB NIH HHS/ -- U54-EB005149/EB/NIBIB NIH HHS/ -- England -- Nature. 2009 Jan 1;457(7225):63-6. doi: 10.1038/nature07609.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Initiative in Innovative Computing at Harvard, Cambridge, Massachusetts 02138, USA. agoodman@cfa.harvard.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19122636" target="_blank"〉PubMed〈/a〉
    Keywords: Algorithms ; Astronomy ; Carbon Monoxide/analysis ; Computer Simulation ; *Gravitation ; Stars, Celestial/*chemistry
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 52
    Publication Date: 2009-02-20
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tollefson, Jeff -- England -- Nature. 2009 Feb 19;457(7232):942-3. doi: 10.1038/457942b.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19225485" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Engineering ; *Federal Government ; Fishes ; *Greenhouse Effect ; History, 20th Century ; History, 21st Century ; Hobbies/history ; Marine Biology ; Physics ; *Research Personnel ; United States ; United States Government Agencies/*organization & administration ; Wine
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 53
    Publication Date: 2006-09-09
    Description: Close-in giant planets (e.g., "hot Jupiters") are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered "hot Earths." Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Raymond, Sean N -- Mandell, Avi M -- Sigurdsson, Steinn -- New York, N.Y. -- Science. 2006 Sep 8;313(5792):1413-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309-0392, USA. raymond@lasp.colorado.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16960000" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; Computer Simulation ; Earth (Planet) ; *Evolution, Planetary ; Iron ; Mathematics ; *Planets ; Temperature ; *Water
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 54
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2006-05-06
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Teich, Al -- White, Wendy D -- New York, N.Y. -- Science. 2006 May 5;312(5774):657.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16675666" target="_blank"〉PubMed〈/a〉
    Keywords: Engineering ; *Foreign Professional Personnel ; Humans ; *International Cooperation ; *Security Measures ; *Students ; Travel ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 55
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2007-04-14
    Description: We have used 19.9 million papers over 5 decades and 2.1 million patents to demonstrate that teams increasingly dominate solo authors in the production of knowledge. Research is increasingly done in teams across nearly all fields. Teams typically produce more frequently cited research than individuals do, and this advantage has been increasing over time. Teams now also produce the exceptionally high-impact research, even where that distinction was once the domain of solo authors. These results are detailed for sciences and engineering, social sciences, arts and humanities, and patents, suggesting that the process of knowledge creation has fundamentally changed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wuchty, Stefan -- Jones, Benjamin F -- Uzzi, Brian -- New York, N.Y. -- Science. 2007 May 18;316(5827):1036-9. Epub 2007 Apr 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Northwestern Institute on Complexity (NICO), Northwestern University, Evanston, IL 60208, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17431139" target="_blank"〉PubMed〈/a〉
    Keywords: *Authorship ; Bibliometrics ; Biomedical Research/statistics & numerical data/trends ; Databases as Topic/statistics & numerical data ; Engineering ; Humanities ; *Knowledge ; *Patents as Topic ; Publishing/statistics & numerical data/*trends ; Research/statistics & numerical data/*trends ; Sociology ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2008-11-22
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bolon, Craig -- New York, N.Y. -- Science. 2008 Nov 21;322(5905):1187. doi: 10.1126/science.322.5905.1187a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19023062" target="_blank"〉PubMed〈/a〉
    Keywords: Engineering ; Lawyers ; *Occupations ; Physicians ; Science
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 57
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2008-03-29
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Travis, John -- New York, N.Y. -- Science. 2008 Mar 28;319(5871):1750-2. doi: 10.1126/science.319.5871.1750.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18369115" target="_blank"〉PubMed〈/a〉
    Keywords: *Awards and Prizes ; *Commerce ; *Diffusion of Innovation ; Drug Industry ; Engineering ; *Internet ; *Problem Solving ; Research ; *Science
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2009-04-18
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, John D -- New York, N.Y. -- Science. 2009 Apr 17;324(5925):344-6. doi: 10.1126/science.1168085.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Mechanical and Industrial Engineering, University of Iowa, Iowa City, IA 52242, USA. jdlee@engineering.uiowa.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19372419" target="_blank"〉PubMed〈/a〉
    Keywords: *Attention ; *Automobile Driving ; Engineering ; Feedback ; Humans ; Risk ; *Safety ; *Technology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 59
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2005-05-10
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bohannon, John -- New York, N.Y. -- Science. 2005 May 6;308(5723):810.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15879205" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; Climate ; *Computer Communication Networks ; *Computer Simulation ; *Computing Methodologies ; *Internet ; *Microcomputers ; Protein Folding ; Proteins/chemistry ; Software
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 60
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2005-08-20
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lawler, Andrew -- New York, N.Y. -- Science. 2005 Aug 19;309(5738):1165.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16109854" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomy ; Biological Science Disciplines ; *Budgets ; History, 20th Century ; History, 21st Century ; Research ; United States ; United States National Aeronautics and Space ; Administration/economics/history/*organization & administration
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 61
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2005-08-16
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Holden, Constance -- New York, N.Y. -- Science. 2005 Aug 12;309(5737):996-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16099953" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; *Biological Evolution ; *Catholicism ; *Religion and Science ; Vatican City
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 62
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2005-06-18
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bhattacharjee, Yudhijit -- New York, N.Y. -- Science. 2005 Jun 17;308(5729):1722-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15961635" target="_blank"〉PubMed〈/a〉
    Keywords: Authorship ; *Aviation ; Commerce ; *Editorial Policies ; Engineering ; International Cooperation ; Iran ; Publishing ; Security Measures ; *Societies, Scientific ; United States
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    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 63
    Publication Date: 2005-04-30
    Description: Agents in creative enterprises are embedded in networks that inspire, support, and evaluate their work. Here, we investigate how the mechanisms by which creative teams self-assemble determine the structure of these collaboration networks. We propose a model for the self-assembly of creative teams that has its basis in three parameters: team size, the fraction of newcomers in new productions, and the tendency of incumbents to repeat previous collaborations. The model suggests that the emergence of a large connected community of practitioners can be described as a phase transition. We find that team assembly mechanisms determine both the structure of the collaboration network and team performance for teams derived from both artistic and scientific fields.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2128751/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2128751/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guimera, Roger -- Uzzi, Brian -- Spiro, Jarrett -- Amaral, Luis A Nunes -- K25 GM069546-03/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2005 Apr 29;308(5722):697-702.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15860629" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; Behavior ; *Cooperative Behavior ; *Creativity ; *Drama ; Ecology ; Economics ; Humans ; *Models, Organizational ; Music ; Psychology, Social ; Publishing ; *Research
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    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 64
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2005-12-24
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉New York, N.Y. -- Science. 2005 Dec 23;310(5756):1880-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16373539" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; Biology ; Brain/growth & development ; Brain Diseases/genetics ; Climate ; Earth (Planet) ; Evolution, Planetary ; Humans ; Nuclear Reactors ; Plant Development ; Plants/genetics ; Potassium Channels ; *Research ; Systems Theory
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 65
    Publication Date: 2005-10-22
    Description: The onset of planet formation in protoplanetary disks is marked by the growth and crystallization of sub-micrometer-sized dust grains accompanied by dust settling toward the disk mid-plane. Here, we present infrared spectra of disks around brown dwarfs and brown dwarf candidates. We show that all three processes occur in such cool disks in a way similar or identical to that in disks around low- and intermediate-mass stars. These results indicate that the onset of planet formation extends to disks around brown dwarfs, suggesting that planet formation is a robust process occurring in most young circumstellar disks.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Apai, Daniel -- Pascucci, Ilaria -- Bouwman, Jeroen -- Natta, Antonella -- Henning, Thomas -- Dullemond, Cornelis P -- New York, N.Y. -- Science. 2005 Nov 4;310(5749):834-6. Epub 2005 Oct 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA. apai@as.arizona.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16239438" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; Cosmic Dust ; Crystallization ; *Evolution, Planetary ; *Planets ; Spectrum Analysis
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    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 66
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2005-09-17
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stone, Richard -- New York, N.Y. -- Science. 2005 Sep 16;309(5742):1802-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16166490" target="_blank"〉PubMed〈/a〉
    Keywords: Astronomical Phenomena ; Astronomy ; *Biotechnology ; Iran ; *Islam ; Physical Phenomena ; Physics ; Publishing ; *Research ; *Science
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 67
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2005-02-12
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mattick, John S -- Gagen, Michael J -- New York, N.Y. -- Science. 2005 Feb 11;307(5711):856-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉ARC Special Research Centre for Functional and Applied Genomics, Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia. j.mattick@imb.uq.edu.au〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15705831" target="_blank"〉PubMed〈/a〉
    Keywords: Computers ; Engineering ; Gene Expression Regulation ; Industry ; *Mathematics ; Software ; *Systems Biology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 68
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2006-10-28
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stokstad, Erik -- New York, N.Y. -- Science. 2006 Oct 27;314(5799):584.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17068235" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Conservation of Natural Resources ; *Ecosystem ; Engineering ; *Environment ; Geologic Sediments ; *Rivers ; *Salmon ; Trees ; Washington
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 69
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2006-10-28
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stokstad, Erik -- New York, N.Y. -- Science. 2006 Oct 27;314(5799):582-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17068234" target="_blank"〉PubMed〈/a〉
    Keywords: California ; Conservation of Natural Resources ; *Ecosystem ; Engineering ; *Environment ; *Fresh Water ; Plant Development ; Rivers ; Water Movements ; Water Supply
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 70
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2006-09-09
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gray, Briahna -- New York, N.Y. -- Science. 2006 Sep 8;313(5792):1382-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16959987" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biological Science Disciplines ; *Biomimetic Materials ; Biomimetics ; Computer Simulation ; Engineering ; *Fishes/physiology ; Interdisciplinary Communication ; Mathematics ; Pressure ; *Sense Organs/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 71
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2006-12-23
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉New York, N.Y. -- Science. 2006 Dec 22;314(5807):1854-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17185569" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Astronomical Phenomena ; Astronomy ; Climate ; Fossils ; Genome ; Genome, Human ; Genomics ; Hominidae ; Humans ; Lasers ; Physical Phenomena ; Physics ; Primates/genetics ; *Science
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 72
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2008-12-06
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Alberts, Bruce -- New York, N.Y. -- Science. 2008 Dec 5;322(5907):1435. doi: 10.1126/science.1168790.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19056942" target="_blank"〉PubMed〈/a〉
    Keywords: Engineering ; *Government ; *Public Policy ; *Science ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 73
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    American Association for the Advancement of Science (AAAS)
    Publication Date: 2009-01-03
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Mervis, Jeffrey -- New York, N.Y. -- Science. 2009 Jan 2;323(5910):32-5. doi: 10.1126/science.323.5910.32.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19119196" target="_blank"〉PubMed〈/a〉
    Keywords: Adult ; Antarctic Regions ; Astronomy ; Australia ; *Autopsy ; Cause of Death ; Coroners and Medical Examiners ; Forensic Pathology ; Humans ; Male ; Methanol/*poisoning ; New Zealand ; Poisoning/diagnosis ; United States ; United States Government Agencies
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 74
    Publication Date: 2018-06-09
    Description: Polycyclic Aromatic Hydrocarbons (PAHs) are an important and ubiquitous component of carbon-bearing materials in space. PAHs are the best-known candidates to account for the IR emission bands (UIR bands) and PAH spectral features are now being used as new probes of the ISM. PAHs are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). In the model dealing with the interstellar spectral features, PAHs are present as a mixture of radicals, ions and neutral species. PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge for laboratory astrophysics is to reproduce (in a realistic way) the physical conditions that exist in the emission and/or absorption interstellar zones. An extensive laboratory program has been developed at NASA Ames to assess the physical and chemical properties of PAHs in such environments and to describe how they influence the radiation and energy balance in space and the interstellar chemistry. In particular, laboratory experiments provide measurements of the spectral characteristics of interstellar PAH analogs from the ultraviolet and visible range to the infrared range for comparison with astronomical data. This paper will focus on the recent progress made in the laboratory to measure the direct absorption spectra of neutral and ionized PAHs in the gas phase in the near-UV and visible range in astrophysically relevant environments. These measurements provide data on PAHs and nanometer-sized particles that can now be directly compared to astronomical observations. The harsh physical conditions of the IS medium - characterized by a low temperature, an absence of collisions and strong VUV radiation fields - are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions are formed from the neutral precursors in an isolated environment at low temperature (of the order of 100 K). The spectra of neutral and ionized PAHs are measured using the high sensitivity methods of cavity ring down spectroscopy (CRDS). These experiments provide unique information on the spectra of free, cold large carbon molecules and ions in the gas phase. Intrinsic band profiles and band positions of cold gas-phase PAHs can now be measured with high-sensitivity spectroscopy and directly compared to the astronomical data. The electronic bands measured for ionized PAH are found to be intrinsically broad (about 20 cm(sup -1)) while the bands associated with the neutral precursors are narrower (of the order of 2 - 10 cm(sup -1)). The laboratory data are discussed and compared with recent astronomical spectra of large and narrow DIBs and with the spectra of circumstellar environments of selected carbon stars and the implications for the interstellar PAH population are derived. Preliminary results also show that carbon nanoparticles are formed during the short residence time of the precursors in the plasma.
    Keywords: Astronomy
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  • 75
    Publication Date: 2018-06-11
    Description: The slosh dynamics in cryogenic fuel tanks under microgravity is a pressing problem that severely affects the reliability of launching spacecraft. After reaching low Earth orbit, the propellant in a multistage rocket experiences large and cyclic changes in temperature as a result of solar heating. Tank wall heating can induce thermal stratification and propellant boiloff, particularly during slosh-inducing vehicle maneuvers. Precise understanding of the dynamic and thermodynamic effects of propellant slosh caused by these maneuvers is critical to mission performance and success. Computational fluid dynamics (CFD) analysis is used extensively within the space vehicle industry in an attempt to characterize the behavior of liquids in microgravity, yet experimental data to quantify these predictions is very limited and reduces confidence in the analytical predictions. A novel approach designed to produce high-fidelity data for correlation to CFD model predictions is being developed with the assistance of Florida Institute of Technology (FIT) and Sierra Lobo, Inc. With few exceptions, previous work in slosh dynamics was theoretical or treated the mass of fuel as a variable of inertia only; such models did not consider the viscosity, surface tension, or other important fluid effects. The challenges in this research are in the development of instrumentation able to measure the required parameters, the computational ability to quantify the fluid behaviors, and the means to assess both the measurements and predictions. The design of this experiment bridges the understanding of slosh dynamics in microgravity by a comprehensive approach that combines CFD tools, dynamic simulation tools, semianalytical models of the predominant fluid effects, and an experimental framework that includes measurement and characterization of liquid slosh in one-degree-of-freedom (DOF) and two-DOF experiments, and ultimately experiments in a NASA low-gravity aircraft.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report; 86-87/88; NASA/TM-2008-214740
    Format: application/pdf
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  • 76
    Publication Date: 2018-06-11
    Description: We present a review of precursor observing programs for the SIM PlanetQuest Key project devoted to detecting Jupiter mass planets around young stars. In order to ensure that the stars in the sample are free of various sources of astrometric noise that might impede the detection of planets, we have initiated programs to collect photometry, high contrast images, interferometric data and radial velocities for stars in both the Northern and Southern hemispheres. We have completed a high contrast imaging survey of target stars in Taurus and the Pleiades and found no definitive common proper motion companions within one arcsecond (140 AU) of the SIM targets. Our radial velocity surveys have shown that many of the target stars in Sco-Cen are fast rotators and a few stars in Taurus and the Pleiades may have sub-stellar companions. Interferometric data of a few stars in Taurus show no signs of stellar or sub-stellar companions with separations of 〈5 mas. The photometric survey suggests that approximately half of the stars initially selected for this program are variable to a degree (1(sigma) 〉0.1 mag) that would degrade the astrometric accuracy achievable for that star. While the precursor programs are still a work in progress, we provide a comprehensive list of all targets ranked according to their viability as a result of the observations taken to date. By far, the observable that removes the most targets from the SIM-YSO program is photometric variability.
    Keywords: Astronomy
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  • 77
    Publication Date: 2018-06-11
    Description: Optical interferometry will open new vistas for astronomy over the next decade. The Space Interferometry Mission (SIM-PlanetQuest), operating unfettered by the Earth's atmosphere, will offer unprecedented astrometric precision that promises the discovery of Earth-analog extra-solar planets as well as a wealth of important astrophysics. Results from SIM will permit the determination of stellar masses to accuracies of 2% or better for objects ranging from brown dwarfs through main sequence stars to evolved white dwarfs, neutron stars, and black holes. Studies of star clusters will yield age determinations and internal dynamics. Microlensing measurements will present the mass spectrum of the Milky Way internal to the Sun while proper motion surveys will show the Sun's orbital radius and speed. Studies of the Galaxy's halo component and companion dwarf galaxies permit the determination of the Milky Way's mass distribution, including its Dark Matter component and the mass distribution and Dark Matter component of the Local Group. Cosmology benefits from precision (1-2%) determination of distances to Cepheid and RR Lyrae standard candles. The emission mechanism of supermassive black holes will be investigated. Finally, radio and optical celestial reference frames will be tied together by an improvement of two orders of magnitude. Optical interferometers present severe technological challenges. The Jet Propulsion Laboratory, with the support of Lockheed Martin Advanced Technology Center (LM ATC) and Northrop Grumman Space Technology (NGST), has addressed these challenges with a technology development program that is now complete. The requirements for SIM have been satisfied, based on outside peer review, using a series of laboratory tests and appropriate computer simulations: laser metrology systems perform with 10 picometer precision; mechanical vibrations have been controlled to nanometers, demonstrating orders of magnitude disturbance rejection; and knowledge of component positions throughout the whole test assembly has been demonstrated to the required picometer level. Technology transfer to the SIM flight team is now well along.
    Keywords: Astronomy
    Type: Proceedings, SPIE; Volume 6693
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  • 78
    Publication Date: 2018-06-11
    Description: Precision astrometry at microarcsecond accuracy has application to a wide range of astrophysical problems. This paper is a study of the science questions that can be addressed using an instrument with flexible scheduling that delivers parallaxes at about 4 microarcsec (microns)as) on targets as faint as V = 20, and differential accuracy of 0.6 (microns)as on bright targets. The science topics are drawn primarily from the Team Key Projects, selected in 2000, for the Space Interferometry Mission PlanetQuest (SIM PlanetQuest). We use the capabilities of this mission to illustrate the importance of the next level of astrometric precision in modern astrophysics. SIM PlanetQuest is currently in the detailed design phase, having completed in 2005 all of the enabling technologies needed for the flight instrument. It will be the first space-based long baseline Michelson interferometer designed for precision astrometry. SIM will contribute strongly to many astronomical fields including stellar and galactic astrophysics, planetary systems around nearby stars, and the study of quasar and AGN nuclei. Using differential astrometry SIM will search for planets with masses as small as an Earth orbiting in the 'habitable zone' around the nearest stars, and could discover many dozen if Earth-like planets are common. It will characterize the multiple-planet systems that are now known to exist, and it will be able to search for terrestrial planets around all of the candidate target stars in the Terrestrial Planet Finder and Darwin mission lists. It will be capable of detecting planets around young stars, thereby providing insights into how planetary systems are born and how they evolve with time. Precision astrometry allows the measurement of accurate dynamical masses for stars in binary systems. SIM will observe significant numbers of very high- and low-mass stars, providing stellar masses to 1%, the accuracy needed to challenge physical models. Using precision proper motion measurements, SIM will probe the Galactic mass distribution, and through studies of tidal tails, the formation and evolution of the Galactic halo. SIM will contribute to cosmology through improved accuracy of the Hubble Constant. With repeated astrometric measurements of the nuclei of active galaxies, SIM will probe the dynamics of accretion disks around supermassive black holes, and the relativistic jets that emerge from them.
    Keywords: Astronomy
    Type: Publications of the Astronomical Society of the Pacific; Volume 120; 38-88
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  • 79
    Publication Date: 2018-06-11
    Description: Large-eddy simulation (LES) is conducted of a three-dimensional temporal mixing layer whose lower stream is initially laden with liquid drops which may evaporate during the simulation. The gas-phase equations are written in an Eulerian frame for two perfect gas species (carrier gas and vapour emanating from the drops), while the liquid-phase equations are written in a Lagrangian frame. The effect of drop evaporation on the gas phase is considered through mass, species, momentum and energy source terms. The drop evolution is modelled using physical drops, or using computational drops to represent the physical drops. Simulations are performed using various LES models previously assessed on a database obtained from direct numerical simulations (DNS). These LES models are for: (i) the subgrid-scale (SGS) fluxes and (ii) the filtered source terms (FSTs) based on computational drops. The LES, which are compared to filtered-and-coarsened (FC) DNS results at the coarser LES grid, are conducted with 64 times fewer grid points than the DNS, and up to 64 times fewer computational than physical drops. It is found that both constant-coefficient and dynamic Smagorinsky SGS-flux models, though numerically stable, are overly dissipative and damp generated small-resolved-scale (SRS) turbulent structures. Although the global growth and mixing predictions of LES using Smagorinsky models are in good agreement with the FC-DNS, the spatial distributions of the drops differ significantly. In contrast, the constant-coefficient scale-similarity model and the dynamic gradient model perform well in predicting most flow features, with the latter model having the advantage of not requiring a priori calibration of the model coefficient. The ability of the dynamic models to determine the model coefficient during LES is found to be essential since the constant-coefficient gradient model, although more accurate than the Smagorinsky model, is not consistently numerically stable despite using DNS-calibrated coefficients. With accurate SGS-flux models, namely scale-similarity and dynamic gradient, the FST model allows up to a 32-fold reduction in computational drops compared to the number of physical drops, without degradation of accuracy; a 64-fold reduction leads to a slight decrease in accuracy.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: Journal of Fuild Mechanics; Volume 523; 37-78
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  • 80
    Publication Date: 2018-06-11
    Description: During its 2005 January opposition, the saturnian system could be viewed at an unusually low phase angle. We surveyed a subset of Saturn's irregular satellites to obtain their true opposition magnitudes, or nearly so, down to phase angle values of 0.01 deg. Combining our data taken at the Palomar 200-inch and Cerro Tololo Inter-American Observatory's 4-m Blanco telescope with those in the literature, we present the first phase curves for nearly half the irregular satellites originally reported by Gladman et al. [2001. Nature 412, 163-166], including Paaliaq (SXX), Siarnaq (SXXIX), Tarvos (SXXI), Ijiraq (SXXII), Albiorix (SXVI), and additionally Phoebe's narrowest angle brightness measured to date. We find centaur-like steepness in the phase curves or opposition surges in most cases with the notable exception of three, Albiorix and Tarvos, which are suspected to be of similar origin based on dynamical arguments, and Siarnaq.During its 2005 January opposition, the saturnian system could be viewed at an unusually low phase angle. We surveyed a subset of Saturn's irregular satellites to obtain their true opposition magnitudes, or nearly so, down to phase angle values of 0.01 deg. Combining our data taken at the Palomar 200-inch and Cerro Tololo Inter-American Observatory's 4-m Blanco telescope with those in the literature, we present the first phase curves for nearly half the irregular satellites originally reported by Gladman et al. [2001. Nature 412, 163-166], including Paaliaq (SXX), Siarnaq (SXXIX), Tarvos (SXXI), Ijiraq (SXXII), Albiorix (SXVI), and additionally Phoebe's narrowest angle brightness measured to date. We find centaur-like steepness in the phase curves or opposition surges in most cases with the notable exception of three, Albiorix and Tarvos, which are suspected to be of similar origin based on dynamical arguments, and Siarnaq.
    Keywords: Astronomy
    Type: Icarus 184 (ISSN 0019-1035); Volume 184; 181-187
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  • 81
    Publication Date: 2018-06-11
    Description: The martian subsurface has been probed to kilometer depths by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument aboard the Mars Express orbiter. Signals penetrate the polar layered deposits, probably imaging the base of the deposits. Data from the northern lowlands of Chryse Planitia have revealed a shallowly buried quasi-circular structure about 250 kilometers in diameter that is interpreted to be an impact basin. In addition, a planar reflector associated with the basin structure may indicate the presence of a low-loss deposit that is more than 1 kilometer thick.
    Keywords: Astronomy
    Type: Science; Volume 310; No. 5756; 1925-1928
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  • 82
    Publication Date: 2018-06-11
    Description: In late 2004 and 2005 the Cassini composite infrared spectrometer (CIRS) obtained spatially resolved thermal infrared radial scans of Saturn's main rings (A, B and C, and Cassini Division) that show ring temperatures decreasing with increasing solar phase angle, (alpha), on both the lit and unlit faces of the ring plane. These temperature differences suggest that Saturn's main rings include a population of ring particles that spin slowly, with a spin period greater than 3.6 h, given their low thermal inertia. The A ring shows the smallest temperature variation with (alpha), and this variation decreases with distance from the planet. This suggests an increasing number of smaller, and/or more rapidly rotating ring particles with more uniform temperatures, resulting perhaps from stirring by the density waves in the outer A ring and/or self-gravity wakes. The temperatures of the A and B rings are correlated with their optical depth, (tau), when viewed from the lit face, and anti-correlated when viewed from the unlit face. On the unlit face of the B ring, not only do the lowest temperatures correlate with the largest (tau), these temperatures are also the same at both low and high a, suggesting that little sunlight is penetrating these regions. The temperature differential from the lit to the unlit side of the rings is a strong, nearly linear, function of optical depth. This is consistent with the expectation that little sunlight penetrates to the dark side of the densest rings, but also suggests that little vertical mixing of ring particles is taking place in the A and B rings.
    Keywords: Astronomy
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  • 83
    Publication Date: 2018-06-11
    Description: Beginning in 2005, an optical measurement center (OMC) was created to measure the photometric signatures of debris pieces. Initially, the OMC was equipped with a 300 W xenon arc lamp, a SBIG 512 x 512 ST8X MEI CCD camera with standard Johnson filters, and a Lynx 6 robotic arm with five degrees of freedom. As research progressed, modifications were made to the equipment. A customized rotary table was built to overcome the robot s limitation of 180 degree wrist rotation and provide complete 360 degree rotation with little human interaction. This change allowed an initial phase angle (source-object-camera angle) of roughly 5 degrees to be adjusted to 7, 10, 15, 18, 20, 25, or 28 degrees. Additionally, the Johnson R and I CCD filters were replaced with the standard astronomical filters suite (Bessell R,I). In an effort to reduce object saturation, the two generic aperture stops were replaced with neutral density filters. Initially data were taken with aluminum debris pieces from the European Space Operations Centre ESOC2 ground test and more recently with samples from a thermal multi-layered insulation (MLI) commonly used on rocket bodies and satellites. The ESOC2 data provided light curve analysis for one type of material but many different shapes, including flat, bent, curled, folded, and torn. The MLI samples are roughly the same size and shape, but have different surfaces that give rise to interesting photometric light curves. In addition, filter photometry was conducted on the MLI pieces, a process that also will be used on the ESOC2 samples. While obtaining light curve data an anomalous drop in intensity was observed when the table revolved through the second 180 degree rotation. Investigation revealed that the robot s wrist rotation is not reliable past 80 degrees, thus the object may be at slightly different angles at the 180 degree transition. To limit this effect, the initial rotation position begins with the object s minimal surface area facing the camera.
    Keywords: Astronomy
    Type: Orbital Debris Quarterly News, Vol. 11, No. 3; 7
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  • 84
    Publication Date: 2018-06-11
    Description: For several years, the Michigan Orbital DEbris Survey Telescope (MODEST), the University of Michigan s 0.6/0.9-m Schmidt telescope on Cerro Tololo Inter-American Observatory in Chile has been used to survey the debris population at GEO in the visible regime. Magnitudes, positions, and angular rates are determined for GEO objects as they move across the telescope s field-of-view (FOV) during a 5-minute window. This short window of time is not long enough to determine a full six parameter orbit so usually a circular orbit is assumed. A longer arc of time is necessary to determine eccentricity and to look for changes in the orbit with time. MODEST can follow objects in real-time, but only at the price of stopping survey operations. A second telescope would allow for longer arcs of orbit to obtain the full six orbital parameters, as well as assess the changes over time. An additional benefit of having a second telescope is the capability of obtaining BVRI colors of the faint targets, aiding efforts to determine the material type of faint debris. For 14 nights in March 2007, two telescopes were used simultaneously to observe the GEO debris field. MODEST was used exclusively in survey mode. As objects were detected, they were handed off in near real-time to the Cerro Tololo 0.9-m telescope for follow-up observations. The goal was to determine orbits and colors for all objects fainter than R = 15th magnitude (corresponds to 1 meter in size assuming a 0.2 albedo) detected by MODEST. The hand-off process was completely functional during the final eight nights and follow-ups for objects from night-to-night were possible. The cutoff magnitude level of 15th was selected on the basis of an abrupt change in the observed angular rate distribution in the MODEST surveys. Objects brighter than 15th magnitude tend to lie on a well defined locus in the angular rate plane (and have orbits in the catalog), while fainter objects fill the plane almost uniformly. We need to determine full six-parameter orbits to investigate what causes this change in observed angular rates. Are these faint objects either the same population of high area-to-mass (A/M) objects on eccentric orbits as discovered by the ESA Space Debris Telescope (Schildknecht, et al. 2004), or are they just normal debris from breakups in GEO?
    Keywords: Astronomy
    Type: Orbital Debris Quarterly News, Vol. 11, No. 3; 6-7
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  • 85
    facet.materialart.
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    In:  CASI
    Publication Date: 2018-06-11
    Description: Phase space symmetries inherent in the statistical theory of ideal magnetohydrodynamic (MHD) turbulence are known to be broken dynamically to produce large-scale coherent magnetic structure. Here, results of a numerical study of decaying MHD turbulence are presented that show large-scale coherent structure also arises and persists in the presence of dissipation. Dynamically broken symmetries in MHD turbulence may thus play a fundamental role in the dynamo process.
    Keywords: Fluid Mechanics and Thermodynamics
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  • 86
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2018-06-12
    Description: A variety of CFD simulations performed by the Combustion Devices CFD Team at Marshall Space Flight Center will be presented. These analyses were performed to support Space Shuttle operations and Ares-1 Crew Launch Vehicle design. Results from the analyses will be shown along with pertinent information on the CFD codes and computational resources used to obtain the results. Six analyses will be presented - two related to the Space Shuttle and four related to the Ares I-1 launch vehicle now under development at NASA. First, a CFD analysis of the flow fields around the Space Shuttle during the first six seconds of flight and potential debris trajectories within those flow fields will be discussed. Second, the combusting flows within the Space Shuttle Main Engine's main combustion chamber will be shown. For the Ares I-1, an analysis of the performance of the roll control thrusters during flight will be described. Several studies are discussed related to the J2-X engine to be used on the upper stage of the Ares I-1 vehicle. A parametric study of the propellant flow sequences and mixture ratios within the GOX/GH2 spark igniters on the J2-X is discussed. Transient simulations will be described that predict the asymmetric pressure loads that occur on the rocket nozzle during the engine start as the nozzle fills with combusting gases. Simulations of issues that affect temperature uniformity within the gas generator used to drive the J-2X turbines will described as well, both upstream of the chamber in the injector manifolds and within the combustion chamber itself.
    Keywords: Fluid Mechanics and Thermodynamics
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  • 87
    facet.materialart.
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    In:  Other Sources
    Publication Date: 2018-06-11
    Description: This slide presentation reviews the use of the a reduced cost version of the Space Interferometry Mission (SIM), called SIM "Lite" to detect potential planets that are earth like around about 60 of the nearest stars.
    Keywords: Astronomy
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  • 88
    Publication Date: 2018-06-12
    Description: New programs are forcing American propulsion system designers into unfamiliar territory. For instance, industry s answer to the cost and reliability goals set out by the Next Generation Launch Technology Program are engine concepts based on the Oxygen- Rich Staged Combustion Cycle. Historical injector design tools are not well suited for this new task. The empirical correlations do not apply directly to the injector concepts associated with the ORSC cycle. These legacy tools focus primarily on performance with environment evaluation a secondary objective. Additionally, the environmental capability of these tools is usually one-dimensional while the actual environments are at least two- and often three-dimensional. CFD has the potential to calculate performance and multi-dimensional environments but its use in the injector design process has been retarded by long solution turnaround times and insufficient demonstrated accuracy. This paper has documented the parallel paths of program support and technology development currently employed at Marshall Space Flight Center in an effort to move CFD to the forefront of injector design. MSFC has established a long-term goal for use of CFD for combustion devices design. The work on injector design is the heart of that vision and the Combustion Devices CFD Simulation Capability Roadmap that focuses the vision. The SRL concept, combining solution fidelity, robustness and accuracy, has been established as a quantitative gauge of current and desired capability. Three examples of current injector analysis for program support have been presented and discussed. These examples are used to establish the current capability at MSFC for these problems. Shortcomings identified from this experience are being used as inputs to the Roadmap process. The SRL evaluation identified lack of demonstrated solution accuracy as a major issue. Accordingly, the MSFC view of code validation and current MSFC-funded validation efforts were discussed in some detail. The objectives of each effort were noted. Issues relative to code validation for injector design were discussed in some detail. The requirement for CFD support during the design of the experiment was noted and discussed in terms of instrumentation placement and experimental rig uncertainty. In conclusion, MSFC has made significant progress in the last two years in advancing CFD toward the goal of application to injector design. A parallel effort focused on program support and technology development via the SCIT Task have enabled the progress.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: Fifth International Symposium on Liquid Space Propulsion; NASA/CP-2005-213607
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  • 89
    Publication Date: 2018-06-12
    Description: The origin of the short (〈2 s) class of gamma-ray bursts (GRBs) is finally becoming clear after decades of search. The first one localized to a few arcseconds accuracy, GRB 050509B, was found to have a highly probable association with a nearby (z = 0.225) elliptical galaxy. A second one with arcsecond localization, GRB 050709, was also associated with a low redshift (z = 0.16) galaxy. We report here the detection of short GRB 050724 with remarkable properties; in particular, it has low energy gamma-ray emission that lasts for 100 s after the main short pulse, strong early X-ray afterglow, and an unusual lightcurve that rebrightens at 3x10(exp 4) s. A position on the sky accurate to 9 arcsec was determined and provided as a GCN alert to ground-based telescopes within 80 s. A subsequent high-resolution X-ray image provided a sub-arcsec position coincident with ground-based optical and radio observations of the afterglow. Like GRB 050509B, this burst is located off-center in an elliptical galaxy. The energy output of the GRB at the host distance of z = 0.258 is 2-3 orders of magnitude less than for long bursts. The low level of star formation in such galaxies is strong evidence against a collapsar or hypernova origin like that associated with long GRBs. Based on these new data, it is highly probable that short GRBs are produced by the coalescence of orbiting neutron stars (NSs) or black holes (BHs), with some evidence for a NS-BH merger in this burst.
    Keywords: Astronomy
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  • 90
    Publication Date: 2018-06-12
    Description: Contemporaneous BAT and XRT observations of two recent well-covered GRBs observed by Swift, GRB 050315 and GRB 050319, show clearly a prompt component of the afterglow emission. The rapid slewing capability of the spacecraft enables X-ray observations immediately after the burst, typically approximately 100 s following the initiation of the prompt gamma-ray phase. By fitting a power law form to the gamma-ray spectrum, we extrapolate the time dependent fluxes measured by the BAT, in the energy band 15 - 350 keV, into the spectral regime observed by the XRT, 0.2 - 10 keV, and examine the functional form of the rate of decay of the two light curves. We find that the BAT and XRT light curves merge to form a unified curve. There is a period of steep decay up to approximately 300 s, followed by a flatter decay. The duration of the steep decay, approximately 100 s in the source frame after correcting for cosmological time dilation, agrees with a theoretical estimate for the deceleration time of the relativistic ejecta as it interacts with circumstellar material. For GRB 050315, the steep decay can be characterized by an exponential form, where T(sub e),(BAT)approximately equal to 24 plus or minus 2 s, and T(sub e)(XRT) approximately equal to 35 plus or minus 2 s. For GRB 050319 a power law decay -d lnf/d lnt = n, where n approximately equal to 3, provides a reasonable fit. The early time X-ray fluxes are consistent with representing the lower energy tail of the prompt emission, and provide our first quantitative measure of the decay of the prompt gamma-ray emission over a large dynamic range. The initial steep decay is expected from the high latitude emission from a curved shell of relativistic plasma illuminated only for a short interval. The overall conclusion is that the prompt phase of GRBs lasts for hundreds of seconds longer than previously thought.
    Keywords: Astronomy
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  • 91
    Publication Date: 2018-06-12
    Description: Advances in micro-fabrication processes have generated tremendous interests in miniaturizing chemical and biomedical analyses into integrated microsystems (Lab-on-Chip devices). To successfully design and operate the micro fluidics system, it is essential to understand the fundamental fluid flow phenomena when channel sizes are shrink to micron or even nano dimensions. One important phenomenon is the electro kinetic effect in micro/nano channels due to the existence of the electrical double layer (EDL) near a solid-liquid interface. Not only EDL is responsible for electro-osmosis pumping when an electric field parallel to the surface is imposed, EDL also causes extra flow resistance (the electro-viscous effect) and flow anomaly (such as early transition from laminar to turbulent flow) observed in pressure-driven microchannel flows. Modeling and simulation of electro-kinetic effects on micro flows poses significant numerical challenge due to the fact that the sizes of the double layer (10 nm up to microns) are very thin compared to channel width (can be up to 100 s of m). Since the typical thickness of the double layer is extremely small compared to the channel width, it would be computationally very costly to capture the velocity profile inside the double layer by placing sufficient number of grid cells in the layer to resolve the velocity changes, especially in complex, 3-d geometries. Existing approaches using "slip" wall velocity and augmented double layer are difficult to use when the flow geometry is complicated, e.g. flow in a T-junction, X-junction, etc. In order to overcome the difficulties arising from those two approaches, we have developed a sub-grid integration method to properly account for the physics of the double layer. The integration approach can be used on simple or complicated flow geometries. Resolution of the double layer is not needed in this approach, and the effects of the double layer can be accounted for at the same time. With this approach, the numeric grid size can be much larger than the thickness of double layer. Presented in this report are a description of the approach, methodology for implementation and several validation simulations for micro flows.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: The 2004 NASA Faculty Fellowship Program Research Reports; VII-1 - VII-5; NASA/CR-2005-213847
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  • 92
    facet.materialart.
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    In:  CASI
    Publication Date: 2018-06-12
    Description: The recent bold initiatives to expand the human presence in space require innovative approaches to the design of propulsion systems whose underlying technology is not yet mature. The space propulsion community has identified a number of candidate concepts. A short list includes solar sails, high-energy-density chemical propellants, electric and electromagnetic accelerators, solar-thermal and nuclear-thermal expanders. For each of these, the underlying physics are relatively well understood. One could easily cite authoritative texts, addressing both the governing equations, and practical solution methods for, e.g. electromagnetic fields, heat transfer, radiation, thermophysics, structural dynamics, particulate kinematics, nuclear energy, power conversion, and fluid dynamics. One could also easily cite scholarly works in which complete equation sets for any one of these physical processes have been accurately solved relative to complex engineered systems. The Advanced Concepts and Analysis Office (ACAO), Space Transportation Directorate, NASA Marshall Space Flight Center, has recently released the first alpha version of a set of computer utilities for performing the applicable physical analyses relative to candidate deep-space propulsion systems such as those listed above. PARSEC, Preliminary Analysis of Revolutionary in-Space Engineering Concepts, enables rapid iterative calculations using several physics tools developed in-house. A complete cycle of the entire tool set takes about twenty minutes. PARSEC is a level-zero/level-one design tool. For PARSEC s proof-of-concept, and preliminary design decision-making, assumptions that significantly simplify the governing equation sets are necessary. To proceed to level-two, one wishes to retain modeling of the underlying physics as close as practical to known applicable first principles. This report describes results of collaboration between ACAO, and Embry-Riddle Aeronautical University (ERAU), to begin building a set of level-two design tools for PARSEC. The "CFD Multiphysics Tool" will be the propulsive element of the tool set. The name acknowledges that space propulsion performance assessment is primarily a fluid mechanics problem. At the core of the CFD Multiphysics Tool is an open-source CFD code, HYP, under development at ERAU. ERAU is renowned for its undergraduate degree program in Aerospace Engineering the largest in the nation. The strength of the program is its applications-oriented curriculum, which culminates in one of three two-course Engineering Design sequences: Aerospace Propulsion, Spacecraft, or Aircraft. This same philosophy applies to the HYP Project, albeit with fluid physics modeling commensurate with graduate research. HYP s purpose, like the Multiphysics Tool s, is to enable calculations of real (three-dimensional; geometrically complex; intended for hardware development) applications of high speed and propulsive fluid flows.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: The 2004 NASA Faculty Fellowship Program Research Reports; XXXIII-5 - XXXIII-5; NASA/CR-2005-213847
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  • 93
    Publication Date: 2018-06-12
    Description: Volatile Removal Assembly (VRA) is a subsystem of the Closed Environment Life Support System (CELSS) installed in the International Space Station. It is used for removing contaminants (volatile organics) in the wastewater produced by the space station crews. The major contaminants are formic acid, ethanol, and propylene glycol. The VRA contains a slim packbed reactor (3.5 cm diameter and four 28 cm long tubes in series) to perform catalyst oxidation of wastewater at elevated pressure and temperature under microgravity conditions. In the reactor, the contaminants are burned with oxygen gas (O2) to form water and carbon dioxide (CO2) that dissolves in the water stream. Optimal design of the reactor requires a thorough understanding about how the reactor performs under microgravity conditions. The objective of this study was to develop a mathematical model to interpret experimental data obtained from normal and microgravity conditions, and to predict the performance of VRA reactor under microgravity conditions. Catalyst oxidation kinetics and the total oxygen-water contact area control the efficiency of catalyst oxidation for mass transfer, which depends on oxygen gas holdup and distribution in the reactor. The process involves bubbly flow in porous media with chemical reactions in microgravity environment. This presents a unique problem in fluid dynamics that has not been studied. Guo et al. (2004) developed a mathematical model that predicts oxygen holdup in the VRA reactor. No mathematical model has been found in the literature that can be used to predict the efficiency of catalyst oxidation under microgravity conditions.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: The 2004 NASA Faculty Fellowship Program Research Reports; XIX-1 - XIX-5; NASA/CR-2005-213847
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  • 94
    Publication Date: 2018-06-12
    Description: The development and analysis of turbomachinery components for industrial and aerospace applications has been greatly enhanced in recent years through the advent of computational fluid dynamics (CFD) codes and techniques. Although the use of this technology has greatly reduced the time required to perform analysis and design, there still remains much room for improvement in the process. In particular, there is a steep learning curve associated with most turbomachinery CFD codes, and the computation times need to be reduced in order to facilitate their integration into standard work processes. Two turbomachinery codes have recently been developed by Dr. Daniel Dorney (MSFC) and Dr. Douglas Sondak (Boston University). These codes are entitled Aardvark (for 2-D and quasi 3-D simulations) and Phantom (for 3-D simulations). The codes utilize the General Equation Set (GES), structured grid methodology, and overset O- and H-grids. The codes have been used with success by Drs. Dorney and Sondak, as well as others within the turbomachinery community, to analyze engine components and other geometries. One of the primary objectives of this study was to establish a set of parametric input values which will enhance convergence rates for steady state simulations, as well as reduce the runtime required for unsteady cases. The goal is to reduce the turnaround time for CFD simulations, thus permitting more design parametrics to be run within a given time period. In addition, other code enhancements to reduce runtimes were investigated and implemented. The other primary goal of the study was to develop enhanced users manuals for Aardvark and Phantom. These manuals are intended to answer most questions for new users, as well as provide valuable detailed information for the experienced user. The existence of detailed user s manuals will enable new users to become proficient with the codes, as well as reducing the dependency of new users on the code authors. In order to achieve the objectives listed, the following tasks were accomplished: 1) Parametric Study Of Preconditioning Parameters And Other Code Inputs; 2) Code Modifications To Reduce Runtimes; 3) Investigation Of Compiler Options To Reduce Code Runtime; and 4) Development/Enhancement of Users Manuals for Aardvark and Phantom
    Keywords: Fluid Mechanics and Thermodynamics
    Type: The 2004 NASA Faculty Fellowship Program Research Reports; XXVI-1 - XXVI-5; NASA/CR-2005-213847
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  • 95
    facet.materialart.
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    In:  CASI
    Publication Date: 2018-06-12
    Description: Specific impulse is defined in words in many ways. Very early in any text on rocket propulsion a phrase similar to .specific impulse is the thrust force per unit propellant weight flow per second. will be found.(2) It is only after seeing the mathematics written down does the definition mean something physically to scientists and engineers responsible for either measuring it or using someone.s value for it.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: The 2004 NASA Faculty Fellowship Program Research Reports; XVIII-1 - XVIII-11; NASA/CR-2005-213847
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  • 96
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2018-06-11
    Description: Planets form inside protostellar disks in a dead zone where the electrical resistivity of the gas is too high for magnetic forces to drive turbulence. We show that much of the dead zone nevertheless is active and flows toward the star while smooth, large-scale magnetic fields transfer the orbital angular momentum radially outward. Stellar X-ray and radionuclide ionization sustain a weak coupling of the dead zone gas to the magnetic fields, despite the rapid recombination of free charges on dust grains. Net radial magnetic fields are generated in the magnetorotational turbulence in the electrically conducting top and bottom surface layers of the disk, and reach the midplane by ohmic diffusion. A toroidal component to the fields is produced near the midplane by the orbital shear. The process is similar to the magnetization of the solar tachocline. The result is a laminar, magnetically driven accretion flow in the region where the planets form.
    Keywords: Astronomy
    Type: The Astrophysical Journal Letters; Volume 679; L131-L134
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  • 97
    Publication Date: 2018-06-11
    Description: The engineering tools of choice for the computation of practical engineering flows have begun to migrate from those based on the traditional Reynolds-averaged Navier-Stokes approach to methodologies capable, in theory if not in practice, of accurately predicting some instantaneous scales of motion in the flow. The migration has largely been driven by both the success of Reynolds-averaged methods over a wide variety of flows as well as the inherent limitations of the method itself. Practitioners, emboldened by their ability to predict a wide-variety of statistically steady, equilibrium turbulent flows, have now turned their attention to flow control and non-equilibrium flows, that is, separation control. This review gives some current priorities in traditional Reynolds-averaged modeling research as well as some methodologies being applied to a new class of turbulent flow control problems.
    Keywords: Fluid Mechanics and Thermodynamics
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  • 98
    Publication Date: 2018-06-11
    Description: Ships produce vortices and air-wakes while either underway or stationary in a wind. These flow fields can be detrimental to the conduction of air operations in that they can adversely impact the air vehicles and flight crews. There are potential solutions to these problems for both frigates/destroyers and carriers through the use of novel vortex flow or flow control devices. This appendix highlights several devices which may have application and points out that traditional wind-tunnel testing using smoke, laser-vapor screen, and Particle Image Velocimetry can be useful in sorting out the effectiveness of different devices.
    Keywords: Fluid Mechanics and Thermodynamics
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  • 99
    Publication Date: 2018-06-12
    Description: We used Hinode X-Ray Telescope (XRT) and Solar Optical Telescope (SOT) filtergraph (FG) Stokes-V magnetogram observations, to study the early onset of a solar eruption that includes an erupting filament that we observe in TRACE EUV images. The filament undergoes a slow rise for at least 20min prior to its fast eruption and strong soft X-ray (SXR) flaring; such slow rises have been previously reported, and the new Hinode data elucidate the physical processes occurring during this period. XRT images show that during the slow-rise phase, an SXR sigmoid forms from apparent reconnection low in the sheared core field traced by the filament, and there is a low-level intensity peak in both EUV and SXRs during the slow rise. MDI and SOT FG Stokes-V magnetograms show that the pre-emption filament is along a neutral line between opposing-polarity enhanced network cells, and the SOT magnetograms show that these opposing fields are flowing together and canceling for at least six hours prior to eruption. From the MDI data we measured the canceling network fields to be approx. 40 G, and we estimated that approx. 10(exp 19)Mx of flux canceled during the five hours prior to eruption; this is only approx.5% of the total flux spanned by the eruption and flare, but apparently its tether-cutting cancellation was enough to destabilize the sigmoid field holding the filament and resulted in that field's eruption.
    Keywords: Astronomy
    Type: Publications of the Astronomical Society of Japan; Volume 59; S823-S829
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  • 100
    Publication Date: 2018-06-12
    Description: We present general relativistic radiation transfer formulations which include opacity effects due to absorption, emission and scattering explicitly. We consider a moment expansions for the transfer in the presence of scattering. The formulation is applied to calculation emissions from accretion and outflows in black-hole systems. Cases with thin accretion disks and accretion tori are considered. Effects, such as emission anisotropy, non-stationary flows and geometrical self-occultation are investigated. Polarisation transfer in curved space-time is discussed qualitatively.
    Keywords: Astronomy
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