Search for dissertations about: "Transient absorption spectroscopy"

Showing result 21 - 25 of 51 swedish dissertations containing the words Transient absorption spectroscopy.

2. 21. Fingerprints of light-induced molecular transients : from quantum chemical models of ultrafast x-ray spectroscopy

   Author : Jesper Norell; Michael Odelius; Sang-Kil Son; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; time-resolved x-ray spectroscopy; quantum chemistry; electronic structure; multi-configurational self-consistent field; density functional theory; molecular dynamics; Born-Oppenheimer dynamics; non-adiabatic dynamics; proton-transfer; charge-transfer; solvatization; Dyson orbital; teoretisk fysik; Theoretical Physics;

   Abstract : Absorption of sunlight generates renewable electricity and powers the growth of plants, but also causes severe damage both to synthetic materials and biological tissue. The wildly varying outcomes of these light-induced processes are ultimately determined by much slighter differences in their underlying reaction pathways, induced by the transient properties of short-lived and miniscule molecules; a powerful approach to their detection and characterization is offered by ultrafast x-ray spectroscopy, with identification of spectral fingerprints and further guidance from quantum chemical models. READ MORE

4. 22. Transient In Situ Studies on Supported Catalysts: CO2 Methanation and Methane Oxidation

   Author : Felix Hemmingsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; CH4 oxidation; Catalytic methanation; Hydrogenation; Sabatier reaction; CO2 reduction; HE-XRD; XAS; DRIFTS; AP-XPS; Heterogeneous catalysis; In situ spectroscopy;

   Abstract : This dissertation aims to increase the understanding of important steps in the catalytic CO2 hydrogenation and total methane oxidation reactions over supported noble metal catalysts. A general theme is the role of the metal oxide support for the catalytic reactions. READ MORE

5. 23. Charge Separation on Localized Surface Plasmon and Hot Carrier Transfer to Semiconductors

   Author : Yocefu Hattori; Jacinto Sá; Stephan Link; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Plasmonics; hot carrier; metal nanoparticles; semiconductors; ultrafast transient absorption spectroscopy; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi;

   Abstract : The relatively recent discovery that plasmonic nanoparticles generate energetic electron-hole pairs known as hot carriers has been the source of interest from many scientific groups. The capability to extract these short-lived hot carriers from metal nanoparticles (NPs) might potentially lead to applications in solar cells, photodetection, and photocatalysis. READ MORE

6. 24. Life of Excitons in Artificial Photosynthetic Antennas

   Author : Johan Andersson; Kemisk fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Zn-porphyrin; Osmium; Ruthenium; Polypyridine; Inter Ligand Energy Transfer; Inter System Crossing; Excited state dynamics; Transition metal complexes; Photosynthetic Antennas; Solar energy conversion; Artificial photosynthesis; Physical chemistry; Fysikalisk kemi; Transient Absorption Anisotropy.; Reaction Center; Dendrimer; Energy Transfer;

   Abstract : Due to the predicted energy crisis when fossil fuels will be exhausted it is important to search for alternative energy sources. Utilizing sunlight via artificial photosynthesis is an interesting possibility. READ MORE

7. 25. Stripped-envelope supernovae discovered by the Palomar Transient Factory

   Author : Christoffer Fremling; Jesper Sollerman; Federica Bianco; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; supernovae; transients; Astronomy; astronomi;

   Abstract : This thesis is based on research made by the intermediate Palomar Transient Factory [(i)PTF]. The focus is on stripped-envelope (SE) supernovae (SNe) discovered by (i)PTF, and it is closely tied to the research on the SE SN iPTF13bvn, that occurred in the nearby galaxy NGC 5806. READ MORE