Sökning: "In-situ contact resistance."
Visar resultat 1 - 5 av 16 avhandlingar innehållade orden In-situ contact resistance..
1. On Gas Contaminants, and Bipolar Plates in Proton Exchange Membrane Fuel Cells
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
2. Development of characterisation methods for the components of the polymer electrolyte fuel cell
Sammanfattning : In this work characterisation methods and fuel cell hardwarewere developed for studying the components of the polymerelectrolyte fuel cell (PEFC). Humidifiers and other componentswere tested in order to develop reproducible and reliableexperimental techniques. A set-up for testing larger cells andstacks was developed. LÄS MER
3. Optimization of Ohmic Contacts and Surface Passivation for ‘Buffer-Free’ GaN HEMT Technologies
Sammanfattning : Gallium nitride high electron mobility transistors (GaN HEMTs) draw attention from high frequency and high power industries due to unique properties including high electron mobility and saturation velocity combined with high breakdown voltage. This makes GaN HEMTs suitable for power devices with high switching speed and high frequency applications with high power density requirements. LÄS MER
4. Low-friction and wear-resistant carbon nitride coatings for bearing components grown by magnetron sputtering
Sammanfattning : The scope of this thesis is the investigation of magnetron sputtered carbon nitride coatings suitable for roller bearing components. The research field of tribology of bearings focuses on minimizing friction between components by improving the lubricants. LÄS MER
5. Electrode degradation in proton exchange membrane fuel cells
Sammanfattning : The topic of this thesis is the degradation of fuel cell electrodes in proton exchange membrane fuel cells (PEMFCs). In particular, the degradation associated with localized fuel starvation, which is often encountered during start-ups and shut-downs (SUs/SDs) of PEMFCs. At SU/SD, O2 and H2 usually coexist in the anode compartment. LÄS MER