Sökning: "solar system: formation"

Visar resultat 6 - 10 av 67 avhandlingar innehållade orden solar system: formation.

1. 6. Disentangling the Early History of the Solar System

   Författare :Simona Pirani; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; planets and satellites: formation; planets and satellites: dynamical evolution and stability; Kuiper belt: general;

   Sammanfattning : Giant planets form out of a disc of gas and dust – called protoplanetary disc -- that surrounded the protosun at the time of its formation. While the cores of giant planets were growing via planetesimal and pebble accretion, they started to interact with the gas in the protoplanetary disc. LÄS MER

3. 7. Origin of solar surface activity and sunspots

   Författare :Sarah Jabbari; Axel Brandenburg; Laurene Jouve; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magneto-hydrodynamics; solar physics; dynamo theory; Astronomy; astronomi;

   Sammanfattning : Sunspots and active regions are two of the many manifestations of the solar magnetic field. This field plays an important role in causing phenomena such as coronal mass ejections, flares, and coronal heating. Therefore, it is important to study the origin of sunspots and active regions and determine the underlying mechanism which creates them. LÄS MER

4. 8. Nanoparticle plasmon influence on the charge carrier generation in solar cells

   Författare :Carl Hägglund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; solar cells; finite element method; nanoparticle plasmons; photovoltaics; nanofabrication; Si; dye sensitized solar cells; localized surface plasmon resonances;

   Sammanfattning : Global warming is a potential threat to life on earth and to human society. It is by much evidence linked to the extensive use of fossil fuels in our present energy system. Replacing the fossil fuels by alternative sources of energy poses a tremendous challenge for mankind, but is not at all undoable. LÄS MER

5. 9. Solar Type Stars as Calibrators : A Photometric and Spectroscopic Study on the Atmospheric Properties of Late-type Stars

   Författare :Anna Önehag; Ulrike Heiter; Andreas Korn; Bengt Gustafsson; Frank Grundahl; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars: atmospheres; stars: late-type; techniques: photometric; stars: abundances; techniques: spectroscopic; Astronomy; Astronomi;

   Sammanfattning : Detailed knowledge of solar-type stars is essential in the understanding of the evolutionary past, presence and future of the Sun as well as the formation of its planetary system. Moreover, solar-type stars are of key significance for the study of the evolution of the Galaxy. The ages of solar-type stars map the full galactic evolution. LÄS MER

7. 10. Magnetic Reconnection in Space Plasmas : Cluster Spacecraft Observations

   Författare :Alessandro Retinò; Mats André; Andris Vaivads; Bengt U. Ö. Sonnerup; Uppsala universitet; []
   Nyckelord :Space and plasma physics; space physics; plasma astrophysics; plasma physics; transport processes; boundary layers; magnetic reconnection; turbulence; particle acceleration; solar system; magnetospheres; Rymd- och plasmafysik;

   Sammanfattning : Magnetic reconnection is a universal process occurring at boundaries between magnetized plasmas, where changes in the topology of the magnetic field lead to the transport of charged particles across the boundaries and to the conversion of electromagnetic energy into kinetic and thermal energy of the particles. Reconnection occurs in laboratory plasmas, in solar system plasmas and it is considered to play a key role in many other space environments such as magnetized stars and accretion disks around stars and planets under formation. LÄS MER