Search for dissertations about: "gas evolution rate"

Showing result 1 - 5 of 60 swedish dissertations containing the words gas evolution rate.

2. 1. Factors Related to the Formation of Gas Porosity in Grey Cast Iron: Investigation of Core Gas Evolution and Gas Concentrations in Molten Iron

   Author : Jessica Orlenius; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; core binders; Gas porosity; hydrogen; grey iron; gas absorption; nitrogen; oxygen; gas evolution rate; green sand; mould filling; gas volume; gas solubility;

   Abstract : Since gas porosity is a major casting problem, it is of greatest importance to increase the knowledge about the foundry process in order to minimise the presence of gas porosity and thereby improving the casting quality. Gas porosity is generally considered to originate from gases precipitated during solidification of iron and from entrained gas picked up by the metal during the mould filling. READ MORE

4. 2. On the origin and evolution of blue compact galaxies

   Author : Göran A. Östlin; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; galaxies - compact; formation; evolution; starburst; interactions; dwarf; photometry; kinematics and dynamics; low surface brightness galaxies; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; astronomi; Astronomy;

   Abstract : This thesis is focused on the origin and evolution of blue compact galaxies (BCGs). BCGs are low mass galaxies characterised by blue colours, low chemical abundances and high star formation rates. The gas consumtion time scale is considerable shorter than the age of the universe and thus the high star formation rate must be transient. READ MORE

5. 3. Studies of Interstellar Molecular Gas in the Magellanic Clouds

   Author : Arto Heikkilä; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; abundances-Galaxies; evolution; molecules-Galaxies; Magellanic Clouds-Interstellar medium; molecules-Galaxies; interstellar medium-Galaxies;

   Abstract : Results of observational studies of interstellar molecular gas clouds in the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), two nearby metal-poor and dust-poor dwarf galaxies, are presented. Spectral line radiation emitted by interstellar molecules has been used to probe the physical state and the chemical composition of individual molecular clouds. READ MORE

6. 4. Gas and dust in early galaxy evolution

   Author : Jean Baptiste Jolly; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Galaxies: evolution -- Galaxies: high-redshift -- methods: stacking -- methods: data analysis -- techniques: interferometric;

   Abstract : In order to study the content of distant galaxies without focusing solely on the brightest objects -- the tip of the iceberg -- I developed a tool:  LineStacker. As its name indicates this tool was designed to perform spectral stacking analyses. READ MORE

7. 5. Exploring the nature of ISM turbulencein disc galaxies

   Author : Timmy Ejdetjärn; Göran Östlin; Oscar Agertz; Garrelt Mellema; Troels Haugbølle; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; galaxies; galaxy; disc galaxy; star formation; ISM; interstellar medium; kinematics; dynamics; evolution; turbulence; numerical; Astronomy; astronomi; teoretisk astrofysik; Theoretical Astrophysics;

   Abstract : Galaxy formation is a continuous process that started only a few hundred million yearsafter the Big Bang. The first galaxies were very volatile, with bursts of star formationand disorganised gas motions. READ MORE