Sökning: "Kemi"

Visar resultat 1 - 5 av 5182 avhandlingar innehållade ordet Kemi.

  1. 1. Theoretical Studies of Natural Gas Hydrates and H-bonded Clusters and Crystals

    Författare :Yuan Liu; Lars Ojamäe; Per-Olov Käll; Ben Slater; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES;

    Sammanfattning : In this thesis H-bonded systems (natural gas hydrates, water clusters, and crystal ice) are studied by density functional theory (DFT) computations.Natural gas hydrates (NGHs) play an important role in energy and environmental fields: NGHs are considered as a promising backup energy resource in the near-future due to their tremendous carbon content; improper exploration of NGHs could induce geological disasters and aggravate the greenhouse effect. LÄS MER

  3. 2. Computational Studies of Chemical Interactions: Molecules, Surfaces and Copper Corrosion

    Författare :Joakim Halldin Stenlid; Tore Brinck; Thomas Bligaard; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; computational chemistry; density functional theory; chemical interactions; reactivity descriptors; copper corrosion; surface and materials science; nucleophilic substitution reactions; heterogeneous catalysis; transition metal oxides; nanotechnology; beräkningskemi; täthetsfunktionalteori; kemiska interaktioner; reaktivitetsdeskriptorer; kopparkorrosion; yt- och materialvetenskap; nukleofila substitutionsreaktioner; heterogen katalys; överångsmetalloxider; nanoteknologi; Kemi; Chemistry;

    Sammanfattning : The chemical bond – a corner stone in science and a prerequisite for life – is the focus of this thesis. Fundamental and applied aspects of chemical bonding are covered including the development of new computational methods for the characterization and rationalization of chemical interactions. LÄS MER

  4. 3. Synthesis of Biomimetic Systems for Proton and Electron Transfer Reactions in the Ground and Excited State

    Författare :Giovanny A. Parada; Sascha Ott; Ana Moore; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Solar energy conversion; artificial photosynthesis; hydrogen bonds; excited state intramolecular proton transfer; tautomerization; proton-coupled electron transfer; photosensitizer; ruthenium complex.; Chemistry with specialization in Organic Chemistry; Kemi med inriktning mot organisk kemi;

    Sammanfattning : A detailed understanding of natural photosynthesis provides inspiration for the development of sustainable and renewable energy sources, i.e. a technology that is capable of converting solar energy directly into chemical fuels. This concept is called artificial photosynthesis. LÄS MER

  5. 4. Chemical signals in interactions between Hylobius abietis and associated bacteria

    Författare :Karolin Axelsson; Jenny Lindh; Anna-Karin Borg-Karlson; Gunaratna Kuttuva Rajarao; Benedicte Albrectsen; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Pine weevil; Hylobius; Rahnella; Pseudomonas; bacteria; fungi; metabolites; 2-methoxyphenol; 2-phenylethanol; Kemi; Chemistry;

    Sammanfattning : The pine weevil (Hylobius abietis L.) is one of the two topmost economically important insect pests in Swedish conifer forests. The damage increase in areas were the silvicultural practice is to use clear cuttings were the insects gather and breed. LÄS MER

  7. 5. 5-Aminolevulinic acid and derivatives thereof : properties, lipid permeability and enzymatic reactions

    Författare :Edvin Erdtman; Leif Eriksson; Tore Brinck; Örebro universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; 5-Aminolevulinic acid; tautomerization; PDT; DFT; MM; QM MM; Porphobilinogen synthase; Uroporphyrinogen III decarboxylase; membrane penetration; enzyme mechanism; Biophysical chemistry; Biofysikalisk kemi; Quantum chemistry; Kvantkemi; Theoretical chemistry; Teoretisk kemi; Fysikalisk kemi; Physical Chemistry; Biochemistry; Biokemi;

    Sammanfattning : 5-aminolevulinic acid (5-ALA) and derivatives thereof are widely usedprodrugs in treatment of pre-malignant skin diseases of the cancer treatmentmethod photodynamic therapy (PDT). The target molecule in 5-ALAPDTis protoporphyrin IX (PpIX), which is synthesized endogenously from5-ALA via the heme pathway in the cell. LÄS MER