Sökning: "orbits"

Visar resultat 1 - 5 av 70 avhandlingar innehållade ordet orbits.

1. 1. Radio meteors above the Arctic Circle : radiants, orbits and estimated magnitudes

   Författare :Csilla Szasz; Asta Pellinen-Wannberg; Noah Brosch; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; meteors; meteoroids; dust; meteor radiants; meteoroid orbits; sporadic sources; radar; meteorradianter; meteoroidbanor; sporadiska källområden; radar; meteorer; meteoroider; interplanetärs stoft; Space engineering; Rymdteknik;

   Sammanfattning : This thesis presents results based on data collected with the 930 MHz EISCAT UHF radar system and three SKiYMet specular meteor radars. It describes in detail a method for meteoroid orbit calculation. The EISCAT UHF system comprises three identical 32 m parabolic antennae: one high-power transmitter/receiver and two remote receivers. LÄS MER

3. 2. The Dynamical Spin Vector Evolution of the Asteroids

   Författare :Erik Skoglöv; Karri Muinonen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; asteroids; Eros; Ceres; Vesta; dynamics; rotation; rotational dynamics; orbits; resonances; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

   Sammanfattning : The dynamical evolution of the spin axis direction due to gravitational and thermal factors is examined. It is found that the spin axis variations generally are regular and relatively small for the bodies in the asteroid main belt. There are also reasons to believe that this is the case for minor objects beyond the main belt. LÄS MER

4. 3. Foam-formed Fiber Networks: Manufacturing, Characterization, and Numerical Modeling : With a Note on the Orientation Behavior of Rod-like Particles in Newtonian Fluids

   Författare :Majid Alimadadi; Per Gradin; Pär Jonsén; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 3D fiber network structure; foam forming; numerical modeling; compression simulation; orientation; wall-bounded flow; CFD; Jeffery orbits; LS-DYNA;

   Sammanfattning : Fiber networks are ubiquitous and are seen in both industrial materials (paper and nonwovens) and biological materials (plant cells and animal tissues). Nature intricately manipulates these network structures by varying their density, aggregation, and fiber orientation to create a variety of functionalities. LÄS MER

5. 4. Mixing and Evaporation at the Cloud Edge and Angular Dynamics of Small Crystals in Viscous Flow

   Författare :Johan Fries; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cloud microphysics; droplet evaporation; reactive flows; Jeffery orbits; shear flow;

   Sammanfattning : How liquid water in atmospheric clouds distributes over droplets of different sizes is important for the initiation of rainfall, and for the optical properties of the atmosphere. Droplet-number densities and droplet-size distributions change rapidly at turbulent cloud edges, where mixing of cloudy and dry air causes cloud dilution and droplet evaporation. LÄS MER

7. 5. Nontypical Behaviour of Orbits and Birkhoff Averages for Expanding Maps

   Författare :David Färm; Matematik LTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; expanding maps; beta-shifts; large intersection classes; Hausdorff dimension;

   Sammanfattning : This thesis consists of an introductory chapter followed by five papers. In the first paper, expanding maps on the unit interval are considered. The set of points for which the forward orbit is bounded away from a given point is studied. It is shown that this set has full Hausdorff dimension and that it has large intersection properties. LÄS MER