Search for dissertations about: "Natural Sciences Physical Sciences Astronomy"

Showing result 11 - 15 of 485 swedish dissertations containing the words Natural Sciences Physical Sciences Astronomy.

  2. 11. Direct Write Technology of SIN Tunnel Junctions for Thermometry and Microwave Devices

    Author : Ernst Otto; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; Cold-Electron Bolometer; direct write technology; SIN tunnel junction;

    Abstract : This thesis concerns development of SIN junction technology for thermometry and microwave detectors, as well as technology of a planar phase switch as a part of integratedmicrowave receiver.Cold-Electron Bolometer (CEB) is a sensitive detector of a microwave radiation, in which SIN tunnel junctions are used for temperature measurement of a nanoscale absorber in thesame way as in SIN thermometers. READ MORE

  4. 12. Cosmological Models and Singularities in General Relativity

    Author : Patrik Sandin; Claes Uggla; Alan Coley; Karlstads universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; general relativity; Bianchi cosmology; singularities; dynamical systems; Fuchsian methods; Hamiltonian methods; Theory of relativity; gravitation; Relativitetsteori; gravitation; Physics; Fysik;

    Abstract : This is a thesis on general relativity. It analyzes dynamical properties of Einstein's field equations in cosmology and in the vicinity of spacetime singularities in a number of different situations. READ MORE

  5. 13. High Resolution Transmission Spectroscopy of Exoplanets

    Author : Ansgar Wehrhahn; Nikolai Piskunov; Ulrike Heiter; Jason Wright; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; astronomy; spectroscopy; Astronomy; Astronomi;

    Abstract : A large number of exoplanets has been observed in the last three decades, but still for most of them we know comparatively little about the atmospheres of these distant planets. This is of particular interest as there exist types of planets that don't have an analogy in our own solar system, like hot Jupiters or super Earths. READ MORE

  6. 14. Chemical Abundance Analysis of Population II Stars : The Summary Includes a Background in General Astronomy

    Author : Karin Jonsell; Bengt Gustafsson; Bengt Edvardsson; Paul Barklem; Christopher Sneden; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomy; Galactic evolution; Halo; Milky Way; Oxygen; r-element; s-element; Stellar abundances; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik;

    Abstract : We are made of stardust in the sense that most atomic nuclei around us have been formed by stars. Stars synthesise new elements and expel them to the interstellar medium, from which later new generations of stars are born. We can map this chemical evolution by analysing the atmospheric contents of old Galactic halo stars. READ MORE

  7. 15. Gas Production in Distant Comets

    Author : Marcus Gunnarsson; F Peter Schloerb; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Comets; Radio Astronomy; Molecular Spectroscopy; Coma Models; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

    Abstract : Molecular spectroscopy at radio wavelengths is a tool well suited for studying the composition and outgassing kinematics of cometary comae. This is particularly true for distant comets, i.e. comets at heliocentric distances greater than a few AU, where the excitation of molecules is inefficient other than for rotational energy levels. READ MORE