Search for dissertations about: "Weight ratios"

Showing result 11 - 15 of 101 swedish dissertations containing the words Weight ratios.

  2. 11. Aerodynamic Design and Experimental Investigation of Short Nacelles for Future Turbofan Engines

    Author : Vinícius Tavares Silva; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultra-high-bypass turbofan; Computational Fluid Dynamics; powered nacelle.; Ultra-short nacelles; experimental; thrust-and-drag bookkeeping;

    Abstract : To achieve a higher propulsive efficiency, and hence reduced fuel burn and emissions, the next generation turbofan engines are expected to have higher bypass ratios and lower fan pressure ratios. However, the larger the bypass ratio, the larger becomes the fan and thus the nacelle. The result is an undesired increase in weight and nacelle drag. READ MORE

  4. 12. High Aspect Ratio Microstructures in Flexible Printed Circuit Boards : Process and Applications

    Author : Hanna Yousef; Klas Hjort; Mikael Lindeberg; Peter Leisner; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; flexible printed circuit boards; polyimide; through-hole vias; ion track technology; thermoelectricity; thermopiles; substrate integrated waveguides; millimeter wave devices; Teknisk fysik; Engineering physics; Teknisk fysik;

    Abstract : Flexible printed circuit boards (flex PCBs) are used in a wide range of electronic devices today due to their light weight, bendability, extensive wiring possibilities, and low-cost manufacturing techniques. The general trend in the flex PCB industry is further miniaturization alongside increasing functionality per device and reduced costs. READ MORE

  5. 13. Seasonal variation and landscape regulation of dissolved organic carbon concentrations and character in Swedish boreal streams

    Author : Anneli Ågren; Mats Jansson; Irena Creed; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; DOC; temporal variation; spatial variation; seasonal variation; forested catchment; wetland catchment; catchment characteristics; DOC characteristics; absorbance-ratio; bioavailability.; Physical geography; Naturgeografi;

    Abstract : The seasonal variation and landscape regulation of dissolved organic carbon (DOC) concentrations in streams have been studied in two watersheds in the boreal zone. The seasonal variation was found to be highly correlated to variations in runoff. An increase in runoff was always accompanied with an increase in DOC concentration. READ MORE

  6. 14. Very preterm birth : etiological aspects and short and long term outcomes

    Author : Stefan Johansson; Karolinska Institutet; Karolinska Institutet; []
    Keywords : ;

    Abstract : Very preterm birth, occurring before 32 completed weeks of gestation, is an often unexplained pregnancy complication affecting approximately 1 to 2 percent of all births. This thesis includes four studies regarding the etiology, and short and long term outcomes of very preterm birth, using Swedish population-based data. READ MORE

  7. 15. Synthesis of functional degradable polymers by radical ring-opening polymerization

    Author : Jenny Undin; Ann-Christine Albertsson; Mats Johansson; Monica Ek; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; tissue engineering; ring-opening polymerization; 2; 2´-azoisobutyronitrile; cyclic ketene acetals; 2-methylene- 1; 3; 6-trioxocane; 2-methylene- 1; 3-dioxepane; vinyl acetate; coopolymerization;

    Abstract : The increased demand for understanding cell-material interactions and subsequently create personalized implants for tissue engineering has resulted in an increased interest in developing new monomers with functional groups. The focus of the work presented in this thesis has been on the synthesis of functional monomers and the polymerization of these into functional amorphous aliphatic polyesters. READ MORE