Search Results - (Author, Cooperation:D. L. Mitchell)
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1Latest Papers from Table of Contents or Articles in PressN. M. Schneider ; J. I. Deighan ; S. K. Jain ; A. Stiepen ; A. I. Stewart ; D. Larson ; D. L. Mitchell ; C. Mazelle ; C. O. Lee ; R. J. Lillis ; J. S. Evans ; D. Brain ; M. H. Stevens ; W. E. McClintock ; M. S. Chaffin ; M. Crismani ; G. M. Holsclaw ; F. Lefevre ; D. Y. Lo ; J. T. Clarke ; F. Montmessin ; B. M. Jakosky
American Association for the Advancement of Science (AAAS)
Published 2015Staff ViewPublication Date: 2015-11-07Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
2Articles: DFG German National LicensesOstro, S. J. ; Rosema, K. D. ; Hudson, R. S. ; Jurgens, R. F. ; Giorgini, J. D. ; Winkler, R. ; Yeomans, D. K. ; Choate, D. ; Rose, R. ; Slade, M. A. ; Howard, S. D. ; Mitchell, D. L.
[s.l.] : Nature Publishing Group
Published 1995Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] TABLE 1 Observation parameters Date Runs UTC interval Phase interval 30 Aug. 3 05:15-05:20 310°-315° 43 05:23-07:07 320°-64° 50 07:13-09:02 86°-211° 27 09:07-10:01 218°-279° 31 Aug. 21 03:39-04:30 59°-120° 52 05:43-07:28 ...Type of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 1572-9605Keywords: magnetohydrodynamics ; ship propulsion ; superconducting magnets ; high-temperature superconductivitySource: Springer Online Journal Archives 1860-2000Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsNotes: Abstract The feasibility of magnetohydrodynamic (MHD) ship propulsion using superconducting magnets is reviewed in light of recent advances in high-temperature superconductivity. The scaling relations for the electrical and hydraulic efficiencies of MHD pump-jets show that overall efficiencies 〉50% are feasible at speeds of 40 knots and higher provided that magnetic fields 〉5T can be maintained over volumes of the order of 100 m3. The development of large-scale electrical machinery and magnets using the high-temperature superconductors now under development could make it practical to construct submersibles for high-speed and silent operation. Low-speed tankers for movement of bulk cargo would be efficient with even lower fields.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1572-9605Keywords: Marine propulsion ; MHD propulsion ; magnetohydrodynamic pumps ; induction-drive propulsion ; ripple motor ; high-temperature superconductors ; electromagnetsSource: Springer Online Journal Archives 1860-2000Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsNotes: Abstract The use of magnetohydrodynamic propulsion for marine applications is reviewed with emphasis on induction-drive systems such as the “ripple” motor. Comparisons are made with direct-drive MHD propulsion systems. Application to pumps for hazardous fluids and liquid-metal coolants are also discussed.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesChaizy, P. ; Rème, H. ; Sauvaud, J. A. ; d'Uston, C. ; Lin, R. P. ; Larson, D. E. ; Mitchell, D. L. ; Anderson, K. A. ; Carlson, C. W. ; Korth, A. ; Mendis, D. A.
[s.l.] : Nature Publishing Group
Published 1991Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The RPA-1 electron electrostatic analyser4 (Fig. 1) on the Giotto spacecraft was designed for measurements of plasma electrons near comet P/Halley (see refs 5-10 for results). Negatively charged ions, however, can also be identified if their thermal and flow speeds are much less than the spacecraft ...Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesKorth, A. ; Marconi, M. L. ; Mendis, D. A. ; Krueger, F. R. ; Richter, A. K. ; Lin, R. P. ; Mitchell, D. L. ; Anderson, K. A. ; Carlson, C. W. ; Rème, H. ; Sauvaud, J. A. ; d'Uston, C.
[s.l.] : Nature Publishing Group
Published 1989Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The PICCA (positive-ion-cluster-composition analyser) instrument uses an electrostatic analyser and measures the ratio Fig. 1 Three consecutive measurements of mass spectra. The time is given in spacecraft event time and corresponds to cometocentric distances of (top to bottom) 4,450, 4,230 ...Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesLyons, M. M. ; Aas, P. ; Pakulski, J. D. ; Van Waasbergen, L. ; Miller, R. V. ; Mitchell, D. L. ; Jeffrey, W. H.
Springer
Published 1998Staff ViewISSN: 1432-1793Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract Ultraviolet radiation (UVR) has been implicated in coral-bleaching processes and UVR may create stress to marine organisms by damage to DNA. Absorption of energy from UVB (280 to 320 nm) induces direct damage to DNA via cyclobutane pyrimidine dimer photoproduct-formation. We examined the extent of DNA damage created by UVR in coral reef microbial communities and whether the coral-surface microlayer (CSM) provides protection from UVR to the microorganisms found there. Diel patterns and depth profiles of UVR effects were examined in coral mucus (coral-surface microlayer, CSM) from Montastraea faveolata and Colpophyllia natans, and water-column samples of similar depths. UV-induced photodamage was determined using a radioimmunoassay specific for cyclobutane pyrimidine dimers (thymine dimers). Significant photodamage was detected in water-column and CSM samples, although the level of damage in CSM samples was consistently lower than in water-column samples collected from the same depth, suggesting the presence of photoprotective mechanisms within the CSM. Diel patterns of photodamage were detected in both water-column and CSM samples, but peak damage occurred earlier in the day for the CSM samples, suggesting differences in damage and repair kinetics between the water column and CSM. The results suggest that microorganisms within the CSM are afforded some protection from UVR stress and that changes in the amount of DNA damage in these organisms may be an indicator of changing UVR stress to corals.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1432-1793Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract DNA strand damage, using the single-cell gel electrophoresis (comet) method, was determined in different-stage embryos of grass shrimp (Palaemonetes pugio) collected from surface waters of a local estuary near Savannah, Georgia, USA. Late-stage embryos collected from the estuarine river at midday in the summer or placed in a solar simulator showed extensive DNA strand damage. The solar simulator, which produced the total irradiance found at midday in the summer at 34°N caused DNA strand damage in embryos similar to that found in sunlight-exposed embryos. A large increase in cyclobutane pyrimidine dimers (18 cyclobutane pyrimidine dimers per 1000 kilobases) were detected in DNA from the late-stage embryos exposed to the solar simulator for 1 h (solar irradiance of 126 μW cm−2). DNA repair took place within a few hours when late-stage embryos collected at midday from the river were transferred to the dark. Early grass-shrimp embryo stages showed no DNA strand damage either after placement in the solar simulator or when collected at midday in the summer. This lack of solar-damaged DNA in early-stage embryos was probably due to the presence of high concentrations of carotenoids, which can act as anti-oxidants to prevent damage from activated oxygen species produced by cells exposed to ultraviolet light. These carotenoids are utilized by the developing embryos, and only low concentrations of carotenoids were present in late embryo stages.Type of Medium: Electronic ResourceURL: