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Visar resultat 1 - 5 av 15 uppsatser som matchar ovanstående sökkriterier.
1. Photophysics of the polymer acceptor PF5-Y5 in organic photovoltaics : A first principles theory based study
Master-uppsats, Karlstads universitet/Institutionen för ingenjörsvetenskap och fysik (from 2013)Sammanfattning : Non-fullerene Acceptors (NFAs) have gathered a great deal of interest for use inorganic photovoltaics (OPVs) due to recent breakthroughs in their power conversion efficiency and other advantages they offer over their Fullerene-based counterparts. In this work, a new promising non-fullerene polymer acceptor, PF5-Y5, have been studied using density functional theory and time-dependent density functional theory; and the effects that oligomer length, geometry relaxation and exchange-correlation interaction has on the exciton binding energies (the difference between optical and fundamental energy gaps) have been investigated. LÄS MER
2. Charge transfer states at polymer solar cell interfaces : Insights from atomic-scale modeling
Master-uppsats, Karlstads universitet/Institutionen för ingenjörsvetenskap och fysik (from 2013)Sammanfattning : Organic solar cells (OSCs) based on non-fullerene acceptors (NFAs) have attracted a great deal of attention in recent years due to their rapidly increasing efficiency and enormous potential. In this work, the optical and electronic properties of systems containing the very promising non-fullerene acceptor PYT have been thoroughly studied with the use of the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). LÄS MER
3. Is there a win for conservation, livelihoods and governance? : the implications of Broussonetia papyrifera as an ecological resource substitute: a field study in Uganda
Master-uppsats, SLU/Dept. of Urban and Rural DevelopmentSammanfattning : Wood extraction and invasive species are commonly perceived as harmful for ecosystem services and detrimental for conservation efforts. However, they can also be beneficial for forests as well as for local communities. Interactions among economic, institutional and ecological factors may in some cases turn these impacts on their head. LÄS MER
4. Svenskars kännedom om Livsmedelsverkets kostråd : En kvantitativ enkätstudie
Kandidat-uppsats, Umeå universitet/Institutionen för kostvetenskapSammanfattning : Bakgrund I Sverige har över hälften av befolkningen övervikt eller fetma, enligt Folkhälsoinstitutet senaste rapport. Ytterligare en folkhälsorapport visar att 11 procent av Sveriges sjukdomsbörda idag beror på ohälsosamma matvanor. LÄS MER
5. Pedagogisk måltid : En enkätstudie om personalens attityder till och erfarenheter av måltider på förskola.
Kandidat-uppsats, Umeå universitet/Institutionen för kostvetenskapSammanfattning : Bakgrund: En pedagogisk måltid på förskola innebär att personalen sitter med barnen och äter maten som serveras samtidigt som de har tillsynsskyldighet. Livsmedelsverkets riktlinjer för pedagogisk måltid är det enda styrdokumentet som finns för skolmåltider i Sverige. LÄS MER