Search for dissertations about: "impurities"

Showing result 11 - 15 of 260 swedish dissertations containing the word impurities.

  2. 11. Hydrogen Impurities and Dislocations in Transition Metals

    Author : Björn von Sydow; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Motion of impurities and dislocations is essential for many material properties of metals. In the present thesis we have made use of different atomistic simulation techniques to study the behavior of hydrogen and edge dislocations in transition metals. We have carried out molecular-dynamics (MD) simulations for hydrogen diffusion in niobium. READ MORE

  4. 12. Influence of defects and impurities on the properties of 2D materials

    Author : Soumyajyoti Haldar; Biplab Sanyal; Olle Eriksson; Torbjörn Björkman; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; 2D Materials; Defects on 2D materials; Impurities on 2D materials; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : Graphene, the thinnest material with a stable 2D structure, is a potential alternative for silicon-based electronics. However, zero band gap of graphene causes a poor on-off ratio of current thus making it unsuitable for logic operations. This problem prompted scientists to find other suitable 2D materials. READ MORE

  5. 13. Particulate airborne impurities : express analysis and health effects

    Author : Kai Wilkinson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : The cumulative effects of air pollutants are of principal concern in research on environmental protection in Sweden. Post-industrial society has imposed many limits on emitted air pollutants, yet the number of reports on the negative effects from them is increasing, largely due to human activity in the form of industrial emissions and increased traffic flows. READ MORE

  6. 14. Electronic properties of intrinsic defects and impurities in GaN

    Author : Tran Thien Duc; Carl Hemmingsson; Galia Pozina; Erik Janzén; Walter Meyer; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : With its outstanding properties such as a wide direct bandgap (3.4 eV), high electron mobility and high breakdown voltage, GaN and its alloys with In and Al are considered as one of the most important semiconductors for optoelectronic devices and high-power and high-frequency transistors. READ MORE

  7. 15. Process Models for CO2 Migration and Leakage : Gas Transport, Pore-Scale Displacement and Effects of Impurities

    Author : Farzad Basirat; Auli Niemi; Karsten Jensen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Geological Carbon Storage; CO2 leakage; Field experiment; Laboratory experiment design; Multi-phase flow; Heterogeneity; Wettability; Pore-scale modeling; Impurity gases; Hydrology; Hydrologi;

    Abstract : Geological Carbon Storage (GCS) is considered as one of the key techniques to reduce the rate of atmospheric emissions of CO2 and thereby to contribute to controlling the global warming. A successful application of a GCS project requires the capability of the formation to trap CO2 for a long term. READ MORE