Sökning: "Spin diffusion"

Visar resultat 11 - 15 av 73 avhandlingar innehållade orden Spin diffusion.

  1. 11. Nuclear Magnetic Relaxation Dispersion and Pulsed-Gradient Spin Echo Studies of Biomolecular Solutions and Amphiphilic Liquid Crystals

    Författare :Haukur Jóhannesson; Biofysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stretched dispersion; DNA hydration; solvent dynamics; NMRD; Random flight simulation; PGSE; Diffusion; Nematic phase; NMR; Amphiphilic liquid crystals; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : Biomolecular solutions and amphiphilic liquid crystals are studied by Nuclear Magnetic Resonance Dispersion (NMRD) and Pulsed-Gradient Spin Echo (PGSE) respectively. A random-flight simulation is performed to obtain the obstructing factors for self-diffusion of small molecules in macrofluids. LÄS MER

  3. 12. 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

  4. 13. Studies of asphaltenes in model systems

    Författare :Jenny-Ann Östlund; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shape; diffusion; stability; geometry; asphaltenes; pulsed field gradient spin echo NMR; sixe; kinetic; flocculation; aggregation;

    Sammanfattning : .... LÄS MER

  5. 14. Structure evolution of spin-coated phase separated EC/HPC films

    Författare :Pierre Carmona; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; spin-coating; controlled drug release; porous film; drug delivery; confocal laser scanning microscope; kinetics; phase separation mechanisms; cellulose; biopolymer; phase separation;

    Sammanfattning : Porous phase-separated films made of ethylcellulose (EC) and hydroxypropylcellulose (HPC) are commonly used for controlled drug release. The structure of these thin films is controlling the drug transport from the core to the surrounding liquid in the stomach or intestine. However, detailed understanding of the structure evolution is lacking. LÄS MER

  7. 15. NMR Studies of Gel-Emulsions; Diffusometry and Applications of Novel Field Gradient Techniques

    Författare :Carin Malmborg; Fysikalisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; modulated gradients; imaging; Physical chemistry; Fysikalisk kemi; NMR; emulsion; diffusion;

    Sammanfattning : The aim of these studies has been to investigate what information that can be obtained on gel-emulsions with nuclear magnetic resonance, NMR, as the investigating tool. The gel-emulsions are important in many technical applications such as in food products, in cosmetic and pharmaceutical formulations, and in emulsion explosives, just to name a few applications. LÄS MER