Sökning: "ionomer"

Visar resultat 6 - 10 av 27 avhandlingar innehållade ordet ionomer.

1. 6. Glass Ionomer Cements with Improved Bioactive and Antibacterial Properties

   Författare :Song Chen; Håkan Engqvist; Wei Xia; Jie Zhou; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; biomaterial; glass ionomer cement; bioactivity; hydroxyapatite; monetite; calcium silicate;

   Sammanfattning : Dental restorative cements are placed in a harsh oral environment where they are subjected to thermal shock, chemical degradation, and repeating masticatory force. The ideal restorative dental cements should have superior mechanical properties, chemical stability, aesthetic, good handling properties, biocompatibility, antibacterial properties, and preferably bioactivity. LÄS MER

3. 7. Membrane Electrode Assemblies Based on Hydrocarbon Ionomers and New Catalyst Supports for PEM Fuel Cells

   Författare :Sophie von Kraemer; Göran Lindbergh; Antonino Aricò; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Catalyst support; Carbon; High Temperature Proton Exchange Membrane Fuel Cell; Hydrocarbon Ionomer; Membrane Electrode Assembly; Nafion; PEFC; PEMFC; Porous Electrode; Sulfonated Polysulfone; Titanium Dioxide; Chemical engineering; Kemiteknik;

   Sammanfattning : The proton exchange membrane fuel cell (PEMFC) is a potential electrochemicalpower device for vehicles, auxiliary power units and small-scale power plants. In themembrane electrode assembly (MEA), which is the core of the PEMFC single cell,oxygen in air and hydrogen electrochemically react on separate sides of a membraneand electrical energy is generated. LÄS MER

4. 8. Clinical aspects of restorative treatment in the primary dentition

   Författare :Mirja Varpio; Göteborgs universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Child; Child; Preschool; Cohort Studies; Composite Resins; chemistry; DMF Index; Dental Caries; epidemiology; microbiology; pathology; therapy; Dental Cavity Preparation; classification; Dental Enamel; pathology; Dental Restoration; Permanent; statistics numerical data; Follow-Up Studies; Glass Ionomer Cements; chemistry; Humans; Molar; Prevalence; Prosthesis Failure; Recurrence; Sweden; epidemiology; Tooth; Deciduous;

   Sammanfattning : The failure rate of restorative treatment in primary teeth was studied in a cohort of children born in 1981 and related to caries diagnosis, prevalence and distribution on different tooth surfaces, and compared with a cohort of children born in 1971. Concurrently, the longevity of composite resin in modified Class 2 cavities in primary molars was followed up and the resistance of deciduous and permanent enamel to acid adjacent to composite resin and glass polyalkeonate cement (GPA) was tested in vitro. LÄS MER

5. 9. Electrode degradation in proton exchange membrane fuel cells

   Författare :Alejandro Oyarce; Göran Lindbergh; Carina Lagergren; Steven Holdcroft; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PEMFC; PEFC; Porous electrodes; Carbon corrosion; Carbon nanotubes; Carbon fibers; Polyhedral carbon nanofoams; Phosphonated hydrocarbon ionomer; Mass-transport losses; Electrode morphology; Electrode collapse; Start-up and shut-down; System strategies; Stainless steel; Bi-polar plates; In-situ contact resistance.;

   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

7. 10. Materials for future power sources

   Författare :Mikael Ludvigsson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Polymer electrolyte fuel cell; lithium polymer battery; polymer electrolyte; cathode materials; Nafion; lithium manganese oxide; lithium cobalt oxide; incorporation; precipitation; FTIR; Raman; X-ray; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Proton exchange membrane fuel cells and lithium polymer batteries are important as future power sources in electronic devices, vehicles and stationary applications. The development of these power sources involves finding and characterising materials that are well suited r the application. LÄS MER