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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Simulations of planet migration driven by the scattering of smaller bodies

Kirsh, David Robert 17 September 2007 (has links)
Planet migration is an important part of the formation of planetary systems, both in the Solar system and in extrasolar systems. When a planet scatters nearby comet- and asteroid-size bodies called planetesimals, a significant angular momentum exchange can occur, enough to cause a rapid, self-sustained migration (change of semi-major axis) of the planet. This migration has been studied for the particular case of the four outer planets of the Solar System, but is not well understood in general. This thesis used the Miranda computer simulation code to perform a broad parameter-space survey of the physical variables that determine the migration of a single planet in a planetesimal disk. A simple model presented within matched well with the dependencies of the migration rate for low-mass planets in relatively high-mass disks. When the planet's mass exceeded that of the planetesimals within a few Hill radii, the migration rate decreased strongly with planet mass. Other trends were identified with the root-mean-squared eccentricity of the planetesimal disk, the mass of the particles dragged by the planet in the corotation region, and the index of the surface density power law. The issue of resolution was also addressed, and it was shown that many previous works in this field may have suffered from being under-resolved. The trends were discussed in the context of an analysis of the scattering process itself, which was performed using a large simulation of massless planetesimals. In particular, a bias in scattering timescales on either side of the planet's orbit leads to a very strong tendency for the planet to migrate inwards, instead of outwards. The results of this work show that planet migration driven by planetesimal scattering should be a widespread phenomenon, especially for low-mass planets such as still-forming protoplanets. The simple model provided here, augmented by many more subtle effects, will prove essential to any future work in this underestimated field. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2007-09-09 14:28:46.501
62

Aqueous alteration of olivine in nakhlite Miller Range (MIL) 03346

Stopar, Julie D January 2007 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2008. / Includes bibliographical references (leaves 208-234). / xiv, 234 leaves, bound ill. (some col.) 29 cm
63

Regolith properties of Mercury derived from observations and modelling /

Warell, Johan, January 2003 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 6 uppsatser.
64

Thermal analysis and thermal control system requirements for a solar sail Mars mission /

Tiedemann, Maik, January 1991 (has links)
Report (M. Eng.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 75-76). Also available via the Internet.
65

Underlying processes of the Jovian decametric radiation

Kennedy, James Richard, January 1976 (has links)
Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 204-208).
66

Geschichte, Gehalt und wissenschaftliche Funktion der Planetendiagramme des frühen Mittelalters /

Liess, Hans-Christoph. January 2002 (has links) (PDF)
Diss. phil.-hist. Univ. Bern, 2002. / Sowohl in gedruckter Form wie auf CD-ROM vorhanden.
67

Higher resolution studies of Jupiter's decametric radio emissions

Thieman, James Richard, January 1977 (has links)
Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 195-199).
68

Teilchenpopulationen in der inneren Jupitermagnetosphäre Untersuchung der EPI-Daten von der Galileo-Probe /

Pehlke, Eckhard. January 2000 (has links)
Kiel, Univ., Diss., 2000. / Computerdatei im Fernzugriff.
69

Titan's interaction with the Saturnian magnetospheric plasma

Backes, Heiko. January 2005 (has links) (PDF)
Köln, University, Diss., 2004.
70

Titan's interaction with the Saturnian magnetospheric plasma /

Backes, Heiko. January 2005 (has links)
Zugl.: Köln, University, Diss., 2004.

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