Sökning: "cathodic activity"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden cathodic activity.
1. Mechanistic studies of localized corrosion of Al alloys by high resolution in-situ and ex-situ probing techniques
Sammanfattning : A multi-analytical approach based on in-situ and ex-situ local probing techniques was employed to investigate localized corrosion mechanisms of some aluminum alloys in chloride containing solutions, focusing on the influence of intermetallic particles (IMPs) in the alloys. In the EN AW-3003 alloy, SEM-EDS analysis revealed constituent and dispersoid IMPs. LÄS MER
2. Electronic structure and spectroscopy calculations in fuel cell catalysis
Sammanfattning : This thesis presents joint experimental and theoretical studies of surface phenomena at an electronic structure level in proton exchange membrane fuel cells (PEM-FC's). The fuel cell activity can be related to the oxygen reduction taking place at the cathodic surface through the oxygen reduction reaction (ORR). LÄS MER
3. Influence of the electrolyte on the electrode reactions in the chlorate process
Sammanfattning : The chlorate process is very energy intensive and a major part of the production costs are for electrical energy. Since the electricity prices are constantly increasing and may also vary periodically, the chlorate plants may be forced to adjust their production rate to the price at each moment in order to minimise their costs. LÄS MER
4. Corrosion of painted galvanized steel pretreated with Zr-based thin films
Sammanfattning : For decades, phosphating has been considered state of the art for pretreating car bodies in order to promote corrosion resistance and paint adhesion. Although it offers excellent corrosion protection, the phosphating process has drawbacks. LÄS MER
5. The influence of Al alloy microstructure on conversion coating formation
Sammanfattning : The formation of conversion coatings based on Ce, trivalent Cr and Ti/Zr is triggered by the local pH increase at cathodic IM sites of the aluminium alloy microstructure. The pH gradient is created over the cathodic intermetallic (IM) sites of the microstructure and its intensity is influenced by their activity which depends on their chemical composition, their size, and spatial distribution. LÄS MER