Sökning: "cross relaxation"

Visar resultat 1 - 5 av 70 avhandlingar innehållade orden cross relaxation.

  1. 1. Theory of water-proton spin relaxation in complex biological systems

    Författare :Zhiwei Chang; Biofysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin relaxation theory; immobilized macromolecules; magnetic relaxation dispersion; integral longitudinal relaxation rate; stochastic Liouville equations; multi-spin systems; cross-mode relaxation; spectral density functions;

    Sammanfattning : In complex biological systems (e.g. gels, cross-linked proteins and biological tissues), the longitudinal spin relaxation of water protons is primarily induced by exchange-mediated orientational randomization (EMOR) of intra- and intermolecular magnetic dipole-dipole couplings. LÄS MER

  3. 2. Probing Dynamics of Oligosaccharides by Interference Phenomena in NMR Relaxation

    Författare :Leila Ghalebani; Jozef Kowalewski; Norbert Mueller; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NMR; sugars; oligosaccharides; carbon-13 relaxation; cross-correlated relaxation; molecular dynamics; internal motion; random jumps; PRE; paramagnetic relaxation; Chemistry; Kemi; fysikalisk kemi; Physical Chemistry;

    Sammanfattning : Oligosaccharides (carbohydrates) are a large class of biological molecules that are important as energy sources in the human body and have enormously varied biological functions. It is generally believed that biological activities of carbohydrates are related to their internal dynamics. LÄS MER

  4. 3. Molecular Association Studied by NMR Spectroscopy

    Författare :Lars Nordstierna; István Furó; Peter Griffiths; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NMR; spin relaxation; self-diffusion; intermolecular cross-relaxation; chemical shift; fluorinated surfactants; hydrogenated surfactant; micelle; non-ideal mixing; adsorption; hydration; surfactant-protein association; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : This Thesis presents studies of molecular association in aqueous solution and at the liquid/solid interface. The investigated molecular systems range from self-aggregating surfactants to hydration water in contact with micelles or individual molecules. In most studies, combinations of various NMR methods were applied. LÄS MER

  5. 4. Relaxation dynamics of perturbed water and other H-bonded liquids

    Författare :Johan Sjöström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; confinement; supercooled water; dielectric relaxation; mixtures;

    Sammanfattning : Most liquids can be supercooled below its melting point where the dynamics dramatically slows down with decreasing temperature until the material appears solid on the experimental time scale and becomes stuck in an out-of-equilibrium configuration, a glass. Water, one of the most abundant substances on earth, is no exception. LÄS MER

  7. 5. Nuclear magnetic resonance studies of water self-diffusion in porous systems

    Författare :Daniel Topgaard; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion diffraction; nonfreezing; anisotropy; tortuosity; cross relaxation; emulsion; starch; cellulose; porous material; water; NMR; self-diffusion; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : Proton nuclear magnetic resonance (NMR) was used to study the self-diffusion of water in porous systems that respond to a change in water content in order to elucidate the porous structure and the properties of the confined water. In the carbohydrate systems cellulose fibers and starch granules, water is free to move throughout the porous objects, albeit with a rate reduced from the value of the bulk liquid, The reduction is related to the tortuosity of the pore space filled by water. LÄS MER