Sökning: "Sunlight"

Visar resultat 11 - 15 av 148 avhandlingar innehållade ordet Sunlight.

1. 11. Electron and Energy Transfer in Supramolecular Complexes Designed for Artificial Photosynthesis

   Författare :Helena Berglund Baudin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; artificial photosynthesis; electron transfer; energy transfer; ruthenium; manganese; Fysik; Physics; Fysik; Physical Chemistry; fysikalisk kemi;

   Sammanfattning : In the society of today the need for alternative energy sources is increasing. The construction of artificial devices for the conversion of sunlight into electricity or fuel seems very attractive from an environmental point of view, since these devices are based on processes that does not necessarily generate any harmful biproducts. LÄS MER

3. 12. Single and Accumulative Electron Transfer – Prerequisites for Artificial Photosynthesis

   Författare :Susanne Karlsson; Leif Hammarström; Hans-Christian Becker; Devens Gust; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Artificial photosynthesis; Photoinduced charge separation; Electron transfer; Energy transfer; Accumulative electon transfer; Donor-acceptor; Ruthenium; Linear arrays; Chemical physics; Kemisk fysik; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

   Sammanfattning : Photoinduced electron transfer is involved in a number of photochemical and photobiological processes. One example of this is photosynthesis, where the absorption of sunlight leads to the formation of charge-separated states by electron transfer. LÄS MER

4. 13. On Numerical Tracer Advection in the Stratosphere and Assimilation of Data from Satellites

   Författare :JOHN RÖSEVALL; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; stratosphere; transport modelling; O3; ozone depletion; data assimilation;

   Sammanfattning : Since the early 1980's, large scale ozone depletion has been observed in the lower regions of the ozone layer over Antarctica when sunlight returns to the polar region in the early spring. The destruction of ozone is attributed to anthropogenic emissions of freon and halon compounds that have augmented the natural stratospheric concentrations of nonreactive Clx and Brx reservoir species with several hundred percent. LÄS MER

5. 14. Analytical methods for studying polychlorinated naphtalene congener profiles and levels in the Environment

   Författare :Ulf Järnberg; Terry Bidleman; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

   Sammanfattning : This thesis describes the development, refinement and application of analytical techniques in conjunction with other methods for studying the environmental occurrence, distribution and transformation of polychlorinated naphthalenes (PCNs). The procedures involve selective high-performance liquid chromatographic fractionation on a styrene-divinylbenzene gel permeation column and 2-(1-pyrenyl)ethyldimethylsilylated silica column combined with high resolution gas chromatography and low resolution mass spectrometry. LÄS MER

7. 15. Photoinduced Processes in Molecular-Inorganic Materials - Design Strategies for Control of Photophysical and Photochemical Processes

   Författare :Elin Sundin; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Photochemistry; hybrid materials; solar energy conversion; charge separation; electron transfer; singlet fission; dye-sensitized semiconductors; mechanistic studies;

   Sammanfattning : Sunlight is the most abundant renewable energy resource on Earth and has the potential to provide our society with clean energy. Despite this abundancy, solar energy corresponds to only a minority of the global energy production. Two major reasons for this are the limited efficiencies of solar cells and the difficulty of storing solar energy. LÄS MER