Sökning: "surface degradation"

Visar resultat 21 - 25 av 487 avhandlingar innehållade orden surface degradation.

  1. 21. Mode and Polarization Control in VCSELs using Surface Structures

    Författare :Åsa Haglund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; single mode; dynamics; surface relief; Semiconductor laser; polarization; vertical-cavity surface-emitting laser; sub-wavelength grating; fabrication;

    Sammanfattning : The vertical-cavity surface-emitting laser (VCSEL) is a novel, low-cost light source with many attractive performance characteristics, such as low operating current, circular output beam, and high modulation bandwidth at low currents. This together with its easy integration into two-dimensional arrays has made it an established transmitter in short-distance single and parallel fiber-optical links, and new applications are continuously arising. LÄS MER

  3. 22. Exploring the Frontiers of Polymer Electrolytes for Battery Applications : From Surface to Bulk

    Författare :Christofer Sångeland; Daniel Brandell; Stefano Passerini; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lithium-ion batteries; solid-state polymer electrolytes; electrochemical stability window; interfaces; ionic conductivity; polycarbonate; polyester; sustainability; sodium-ion;

    Sammanfattning : Lithium-ion batteries have dominated the market since their inception in 1991 due to their unparalleled energy and power densities, but are now faced with new challenges. Growing demand for battery materials for energy intense applications and large-scale interim energy storage have emphasized the need for safe and sustainable battery electrolytes. LÄS MER

  4. 23. Electrode Degradation in Polymer Electrolyte Fuel Cells

    Författare :Linnéa Strandberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Catalyst degradation; Platinum stability; Fuel cells;

    Sammanfattning : To mitigate the climate crisis, and reduce carbon emissions from e.g. the transport and energy sectors, hydrogen has been proposed to be used as an environmentally friendly alternative energy carrier. LÄS MER

  5. 24. Surface Integrity and Fatigue Performance of Nickel-based Superalloys

    Författare :Zhe Chen; Ru Peng; Johan Moverare; Sten Johansson; Manuel François; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Due to global warming, the demand for more efficient gas turbines has increased. A way to achieve this, is by increasing the operating temperature of the gas turbine. Therefore, nickel-based superalloys have been developed to withstand these extreme temperatures and loads, especially in the hot sections. LÄS MER

  7. 25. Influence of deformation and environmental degradation of Inconel 792

    Författare :Jan-erik Kanesund; Christer Burman; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Industrial gas turbines are often used as a mechanical drive for pumps and compressors or in power generation as an electric power supply. The gas turbine has for many years been a popular engine due to its flexibility with respect to different types of fuel and due to a design, that enables a high power-to-weight ratio. LÄS MER