Search for dissertations about: "transient absorption"

Showing result 6 - 10 of 94 swedish dissertations containing the words transient absorption.

2. 6. Stepping into Catalysis : Kinetic and Mechanistic Investigations of Photo- and Electrocatalytic Hydrogen Production with Natural and Synthetic Molecular Catalysts

   Author : Daniel Streich; Leif Hammarström; Reiner Lomoth; Clifford Kubiak; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Artificial photosynthesis; photocatalysis; electrocatalysis; hydrogen production; proton reduction; hydrogenase; iron complex; active site model; catalytic mechanism; transient absorption; spectroscopy; electrochemistry; cyclic voltammetry; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

   Abstract : In light of its rapidly growing energy demand, human society has an urgent need to become much more strongly reliant on renewable and sustainable energy carriers. Molecular hydrogen made from water with solar energy could provide an ideal case. READ MORE

4. 7. Mechanistic Studies on Proton-Coupled Electron Transfer from Tyrosine and Tryptophan Derivatives

   Author : Astrid Nilsen-Moe; Leif Hammarström; Pia Ädelroth; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Proton-Coupled Electron Transfer; PCET; Tyrosine; Tryptophan; Amino Acid Radicals; Transient Absorption; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi;

   Abstract : Proton-coupled electron transfer (PCET) from tyrosine (Y) and tryptophan (W) is vital to many redox reactions in Nature where PCET between several Ys, or Ws, or between a mix of Ys and Ws can be used to transfer electrons, or protons, or both over large distances of several Å. Studying the PCET reaction mechanisms of Y and W is important for fundamental knowledge, and can help researchers that wish to mimic redox reactions in Nature. READ MORE

5. 8. Interaction mechanisms for a laser-induced metallic boiling front

   Author : Ramiz Saeed Matti Samarjy; Alexander F.H. Kaplan; Torbjörn Ilar; Michael Schmidt; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser remote fusion cutting; Boiling front; High speed imaging; Additive manufacturing; Ejection; Absorption; Wavy surface; Deposition; Produktionsutveckling; Manufacturing Systems Engineering;

   Abstract : This thesis is about fundamental interaction mechanisms of laser remote fusion cutting, RFC, which is based on the formation of a quasi-stationary laser-induced boiling front that causes drop ejection, preferably downwards. Laser cutting of metals, invented in 1967, has developed from a niche to a well established high quality cutting technique in the manufacturing industry. READ MORE

6. 9. Moisture transport and fixation in porous materials at high moisture levels

   Author : Mårten Janz; Avdelningen för Byggnadsmaterial; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; building construction; water retention curve; diffusivity; suction; Moisture transport; moisture fixation; absorption; capillary transport; byggnadsteknik;

   Abstract : The work presented in this thesis focuses on developing methods of measuring moisture properties at high moisture levels. Paper I deal with a new method of measuring moisture diffusivity at high moisture levels. Papers II to IV present methods of measuring moisture storage capacity as well as results from such measurements. READ MORE

7. 10. Proton-Coupled Electron Transfer from Hydrogen-Bonded Phenols

   Author : Tania Irebo; Leif Hammarström; James M. Mayer; Uppsala universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE