Sökning: "hans karlsson"

Visar resultat 11 - 15 av 25 avhandlingar innehållade orden hans karlsson.

  1. 11. Purification, Stereoisomeric Analysis and Quantification of Biologically Active Compounds in Extracts from Pine Sawflies, African Butterflies and Orchid Bees

    Författare :Joakim Bång; Erik Hedenström; Kristina Sjödin; Hans-Erik Högberg; Anna-Karin Borg-Karlsson; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Semiochemicals; sex pheromone; pine sawflies; Bicyclus; Euglossa; chiral separation; derivatisation; GC-­MS; Organic chemistry; Organisk kemi;

    Sammanfattning : Stereochemistry plays an important role in nature because biologically important molecules such as amino acids, nucleotides and sugars, only exist in enantiomerically pure forms. Semiochemicals carry messages, between the same species (pheromones) and between different species (allelochemicals). LÄS MER

  2. 12. Reflector Optimization for Low Concentration Photovoltaic-Thermal Solar Collectors

    Författare :Diogo Cabral; Hans Wigö; Björn O. Karlsson; Maria João Carvalho; Högskolan i Gävle; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photovoltaic-thermal collector; experimental assessment; collector performance assessment; optical efficiency; concentrating PVT solar collector; ray tracing; Fotovoltaisk-termisk kollektor; experimentell utvärdering; prestandautvärdering; optisk effektivitet; koncentrerande PVT-solfångare; strålgångsanalys;

    Sammanfattning : The alarming new global warming and increasing awareness related to climate change (mainly due to the high emissions of carbon dioxide) in recent decades linked all nations into a common cause, which requires ambitious efforts to combat climate change by adapting energy systems to its effects.The knowledge gain presented in this dissertation establishes the foundations for the development of a more efficient concentrating photovoltaic-thermal (PVT) solar collector. LÄS MER

  3. 13. Effect of austenitising temperature and cooling rate on microstructures of hot-work tool steels

    Författare :María Teresa Coll Ferrari; Leif Karlsson; Hans-Olof Andrén; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tool steel; Heat Treatment; Austenitising Temperature; Large Tools; Tempering Carbides; Bainitic Microstructures; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : The average size of hot-work tools has gradually increased over the past years.This affects the effective temperature cycle tools experience during hardening,as large dimensions prevent uniform and rapid cooling, and thereby the resulting microstructures and properties. LÄS MER

  4. 14. Theoretical Studies of Ground and Excited State Reactivity

    Författare :Pooria Farahani; Marcus Lundberg; Hans Karlsson; Isabelle Navizet; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemical Reactivity; Computational Chemistry; Dynamics; Ground and Excited States; Chemiluminescence; Atmospheric Chemistry;

    Sammanfattning : To exemplify how theoretical chemistry can be applied to understand ground and excited state reactivity, four different chemical reactions have been modeled. The ground state chemical reactions are the simplest models in chemistry. To begin, a route to break down halomethanes through reactions with ground state cyano radical has been selected. LÄS MER

  5. 15. Theoretical Studies of Seemingly Simple Chemical Reactions

    Författare :Pooria Farahani; Hans O. Karlsson; Marcus Lundberg; Henrik Ottosson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER