Sökning: "1H NMR"

Visar resultat 21 - 25 av 124 avhandlingar innehållade orden 1H NMR.

  1. 21. Investigation of [N-X-N]+ and [N-C-N]+ complexes in solution : Exploring Geometry, Stability and Symmetry

    Författare :Alavi Karim; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; three center four electron; halonium; carbenium; carbonium; pentavalent; symmetry; NMR; variable temperature; counterion; isotopic perturbation of equilibrium;

    Sammanfattning : Halogen bonding is a weak interaction. In this thesis the three center four electron halogen bond, [N−X−N]+, has been studied. The lighter halogens form highly unstable halonium ions that are reactive towards nucleophiles and their complexes were therefore investigated at low temperatures. LÄS MER

  3. 22. Synthesis and analysis of carbohydrates related to bacterial polysaccharides

    Författare :Hani Mobarak; Göran Widmalm; Ulf Nilsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbohydrates; synthesis; conformation; NMR; O-antigen; computer-assisted structure elucidation; Organic Chemistry; organisk kemi;

    Sammanfattning : The outer surface of bacteria is composed of around 75% carbohydrates, which are vital for the bacteria to survive and communicate with the host biological system. The thesis discusses different properties of carbohydrates that are essential for understanding the bacterial behavior in biological systems. LÄS MER

  4. 23. Chemistry of Combustion Products Investigation of Combustion Chamber Deposits Formed in a Gasoline Direct Injection Stratified Charge SI Engine

    Författare :Farshid Owrang; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gasoline fuels; SI engine; gasoline direct injection; stratified charge; combustion chamber deposits; engine oil; oxidation; in situ measurement; thermal desorption; GC MS; fast neutron activation analysis; spin-lattice relaxation constant; NMR;

    Sammanfattning : The aim of this work was to characterize deposits formed in the combustion chambers of a gasoline direct injection stratified charge SI engine. The engine was run with several types of gasoline fuels and a special reference engine oil. LÄS MER

  5. 24. Membrane interactions of glycosyltransferases

    Författare :Jobst Liebau; Lena Mäler; Christofer Lendel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lipid; bicelle; glycosyltransferase; NMR; Biophysics; biofysik;

    Sammanfattning : Many important biological processes occur near or in membranes. The role of membranes is not merely confined to compartmentalization, they also form the matrix for membrane associated proteins and are of functional importance. Membrane associated proteins on the other hand require specific membrane properties for proper function. LÄS MER

  7. 25. Magnetic relaxation studies of self-associating and membrane proteins

    Författare :Michael Gottschalk; Lund University Bioimaging Center; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; beta-lactoglobulin A; Biokemisk teknik; Biochemical technology; HEWL; BPTI; bacteriorhodopsin; protein self-association; membrane proteins; NMR; magnetic relaxation dispersion;

    Sammanfattning : Magnetic relaxation dispersion measurements have been performed on aqueous protein solutions to study the dynamics of waters in the proton transport channel of bacteriorhodopsin and the self-association of the proteins BPTI, lysozyme and beta-lactoglobulin. The measurements have focused on the bulk relaxation rates, R1 and R2, of three water nuclei 1H, 2H and 17O that are coupled to the protein environments by exchange and therefore report on properties such as the protein tumbling and dynamics of internal waters. LÄS MER