Sökning: "vätgas"

Visar resultat 11 - 15 av 58 avhandlingar innehållade ordet vätgas.

1. 11. Mimicking Photosystem II with Manganese Model Complexes to Approach Artificial Photosynthesis

   Författare :Joakim Högblom; Biokemi och Strukturbiologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Metabolism; Hydrogen; EPR; Cobalt; Biokemi; metabolism; Biochemistry;

   Sammanfattning : The work in thesis aims for artificial photosyntesis, which could and will mimic natural photosynthesis, the process that uses light to create energy rich compounds from H2O and CO2. Water is oxidized in Photosystem II (PSII) by the Water Oxidizing Complex (WOC), which is a catalytic site on the lumenal side of the thylakoid membrane. LÄS MER

3. 12. The Impact of Hydrocarbon and Carbon Oxide Impuritiesin the Hydrogen Feed of a PEM Fuel Cell

   Författare :Katrin Kortsdottir; Rakel Wreland Lindström; Göran Lindbergh; Tanja Kallio; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fuel Cell; Hydrogen Impurities; Carbon Monoxide; Carbon Dioxide; Ethene; Propene; Methane; Propane; Toluene; Electrochemically Active Surface Area; Cyclic Voltammetry; Mass Spectrometry; bränslecell; vätgasföroreningar; kolmonoxid; koldioxid; eten; propen; metan; propan; toluen; elektrokemisk aktiv yta; cyklisk voltammetri; masspektrometri; Chemical Engineering; Kemiteknik;

   Sammanfattning : The proton exchange membrane fuel cell generates electricity from hydrogen and oxygen (from air) through electrocatalytic reactions in an electrochemical cell. The Pt/C catalyst, commonly used in PEM fuel cells, is very sensitive to impurities that can interact with the active catalyst sites and limit fuel cell performance. LÄS MER

4. 13. 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

5. 14. The dynamic behavior of the NiMH battery – Creating a versatile NiMH battery model

   Författare :Jenny Börjesson Axén; Göran Lindbergh; Henrik Ekström; Erika Widenkvist Zetterström; Paul Albertus; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NiMH batteries; Battery Modeling; OCV hysteresis; NiMH gas phase; P2D model; NiMH batterier; Batterimodellering; OCV hysteres; NiMH gasfas; P2D modell; Chemical Engineering; Kemiteknik;

   Sammanfattning : To facilitate the shift from fossil to renewable energy sources, energy storage is needed to cope with the intermittent nature of technologies such as solar, wind, and wave power. One storage alternative is battery-based stationary energy storage. LÄS MER

7. 15. On the Impact of Piston Motion and In-Cylinder Charge Composition on Energy Release, Auto Ignition and Emission Formation in Premixed Charge Internal Combustion Engines

   Författare :Ola Stenlåås; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bränslen; sprängämnen; Carbochemistry; petrochemistry; fuels and explosives technology; Petrokemi; Internal Combustion Engine; Emission; SI; Spark Ignition; HCCI; Homogeneous Charge Compression Ignition; zone model; Chemical Kinetic; Engine simulation; Reformed Methanol; Hydrogen; Knock; Auto Ignition; NO; Piston Motion; Nitric Oxide; Premixed Charge;

   Sammanfattning : The results presented in this thesis can be divided into four areas of investigation: Investigation of the effect of new volume-crank angle relations on engine emissions, power and efficiency; investigation of nitrogen oxides effect on auto ignition and knock in SI engines; investigation of premixed SI and HCCI engine operation with the alternative fuels hydrogen and reformed methanol gas (RMG); software development of a detailed chemical kinetics zonal engine model. Model development of the in-house two-zone chemical kinetic code focused on expansion of the Jacobian matrix to allow simulations of variable in-cylinder charge. LÄS MER