Sökning: "degradering"

Visar resultat 1 - 5 av 30 avhandlingar innehållade ordet degradering.

1. 1. Electrochemical Reactions in Polymer Electrolyte Fuel Cells

   Författare :Maria Wesselmark; Svein Sunde; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fuel cell; model electrodes; oxygen reduction; methanol oxidation; formic acid oxidation; hydrogen oxidation; CO oxidation; degradation; tungsten oxide; carbon support; Bränslecell; modellelektroder; syrgasreduktion; metanoloxidation; myrsyraoxidation; vätgasoxidation; CO oxidation; degradering; wolfram oxid; kolsupport; Chemical engineering; Kemiteknik;

   Sammanfattning : The polymer electrolyte fuel cell converts the chemical energy in a fuel, e.g. hydrogen or methanol, and oxygen into electrical energy. The high efficiency and the possibility to use fuel from renewable sources make them attractive as energy converters in future sustainable energy systems. LÄS MER

3. 2. On Gas Contaminants, and Bipolar Plates in Proton Exchange Membrane Fuel Cells

   Författare :Yasna Acevedo Gomez; Carina Lagergren; Göran Lindbergh; Rakel Wreland Lindström; Qinfeng Li; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PEM fuel cell; contaminants; ammonia; nitrogen dioxide; degradation; recovery; bipolar plates; electroplating; Ni-Mo; Ni-Mo-P; internal contact resistance; PEM bränslecell; föroreningar; ammoniak; kvävedioxid; degradering; återhämtning; bipolära plattor; elektroplätering; Ni-Mo; Ni-Mo-P; interna kontaktmotståndet; Chemical Engineering; Kemiteknik;

   Sammanfattning : The proton exchange membrane (PEM) fuel cell is an electrochemical device that converts chemical energy into electrical energy through two electrocatalytic reactions. The most common catalyst used is platinum on carbon (Pt/C), which has shown the best performance in the fuel cell until now. LÄS MER

4. 3. Copper-related light-induced degradation in crystalline silicon

   Författare :Jeanette Lindroos; Hele Savin; Eicke R. Weber; Finland Aalto University; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; copper; degradation; lifetime; nickel; silicon; degradering; kisel; koppar; livstid; nickel;

   Sammanfattning : .... LÄS MER

5. 4. Predictive Models for Railway Track Geometry Degradation

   Författare :Iman Soleimanmeigouni; Alireza Ahmadi; Nalinaksh S. Vyas; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Data-driven models; Degradation; Inspection; Maintenance; Predictive analytics; Tamping; Track geometry; Railway infrastructure; RAMS; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : Railways are a vital and effective means of mass transportation and play a vital role in modern transportation and social development. The benefits of the railway compared to other transportation modes are a high capacity, high efficiency and low pollution, and owing to these advantages, railways are nowadays experiencing a higher demand for the transportation of passengers and goods. LÄS MER

7. 5. Studies on the thermal degradation of thermosetting polyimides and their composites

   Författare :Valeri Petkov; Patrik Fernberg; Guan Gong; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymer composites; Polyimide; Thermal oxidative degradation; Polymeric Composite Materials; Polymera kompositmaterial;

   Sammanfattning : The thesis contains a background and reflections section, an introduction, and three appended articles. The first section is reserved for some of the background and basics on polymers and polymer composites and a discussion on their effect on our everyday lives. The introduction gives a brief recap of the project. LÄS MER