Sökning: "PROTON"

Visar resultat 16 - 20 av 801 avhandlingar innehållade ordet PROTON.

  1. 16. Neutron scattering investigations of proton dynamics in acceptor doped barium zirconates

    Författare :Daria Noferini; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; fuel cells; energy materials; Proton conductors; neutron scattering; QENS; proton dynamics; perovskites;

    Sammanfattning : Hydrogen fuel cells represent one of the most promising sustainable technologies for energy conversion. The advantages of the combination of a solid state electrolyteand low operational temperatures (... LÄS MER

  3. 17. Proton transfer in nitric oxide reducing heme-copper oxidases

    Författare :Joachim Reimann; Pia Ädelroth; Peter Brzezinski; Michael Wilson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; heme-copper oxidases; nitric oxide; proton transfer; electron transfer; proton-transfer pathway; Biochemistry; biokemi;

    Sammanfattning : Heme-copper oxidases (HCuOs) are best known as terminal oxidases in the aerobic respiratory chain, in which they catalyze the reduction of oxygen to water. By receiving protons and electrons from opposite sides of the membrane as well as pumping protons, HCuOs contribute to the electrochemical proton gradient over the membrane that can be used for ATP synthesis. LÄS MER

  4. 18. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

    Författare :Joakim Nyman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

    Sammanfattning : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. LÄS MER

  5. 19. Proton-Coupled Electron Transfer from Hydrogen-Bonded Phenols

    Författare :Tania Irebo; Leif Hammarström; James M. Mayer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Proton-coupled electron transfer; phenol oxidation; hydrogen bonds; artificial photosynthesis; promoting vibrations; proton transfer; laser flash-quench; transient absorption.; Physical chemistry; Fysikalisk kemi; Fysikalisk kemi; Physical Chemistry;

    Sammanfattning : Proton-coupled electron transfer (PCET) is one of the elementary reactions occurring in many chemical and biological systems, such as photosystem II where the oxidation of tyrosine (TyrZ) is coupled to deprotonation of the phenolic proton. This reaction is here modelled by the oxidation of a phenol covalently linked to a Ru(bpy)32+-moitey, which is photo-oxidized by a laser flash-quench method. LÄS MER

  7. 20. Neutron scattering for sustainable energy materials: investigations of proton dynamics in acceptor doped barium zirconates

    Författare :Daria Noferini; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; neutron scattering; fuel cells; QENS; Proton conductors; perovskites; proton dynamics; energy materials;

    Sammanfattning : Proton conducting oxides are currently receiving considerable attention for their present or potential use as electrolytes in technological devices such as sensors and electrolysers and, in particular, solid oxide fuel cells, which are among the most promising apparatuses for energy conversion. One of the main challenges for these latter devices is to combine the advantages of a solid electrolyte with those of operational temperatures below 750 °C, which is currently hampered by insufficient conductivities in the targeted temperature range. LÄS MER