Sökning: "nuclear magnetic resonance NMR"

Visar resultat 11 - 15 av 215 avhandlingar innehållade orden nuclear magnetic resonance NMR.

1. 11. 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

3. 12. Molecular dynamics studied by NMR relaxation experiments. Characterization of functional dynamics in the FK506 binding protein FKBP12

   Författare :Ulrika Brath; Biofysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nuclear magnetic resonance; NMR; FK506; protein dynamics; chemical exchange; spin relaxation; FKBP12; FKBP; isotope labeling;

   Sammanfattning : The presented thesis work is concerned with the study of molecular dynamics using liquid nuclear magnetic resonance (NMR) spectroscopy. Spin relaxation dispersion experiments in the rotating frame (R1ρ) are employed to provide a detailed, atomic-resolution view of protein dynamics. LÄS MER

4. 13. Rotational Resonance in the Nuclear Magnetic Resonance of solids

   Författare :Torgny Karlsson; S Vega; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical Chemistry; fysikalisk kemi;

   Sammanfattning : This thesis presents new physical phenomena in the rotational resonance NMR of magic-angle spinning solids. The theory of a new class of nuclear spin echoes is developed. LÄS MER

5. 14. Physico-Chemical Properties of Plant Polysaccharides Investigated with NMR Techniques

   Författare :Åsa Östlund; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NMR diffusometry; Dissolution of cellulose; Chemical shift imaging; Fiber hornification; Xylan; Molecular weight; Pore size distribution; Cryoporometry; Cellulose solution; 19F NMR; Gelation of cellulose; Self-diffusion; Pulsed field gradient NMR; TBAF DMSO; 1H NMR;

   Sammanfattning : In the lead of developing new biomaterials from plant sources it is of importance to be able to control and vary the properties, such as flexibility, strength, and hygroscopicity of the final material. These properties are highly directed by the interactions between constituents on a molecular level. LÄS MER

7. 15. Nuclear magnetic resonance and microcirculation: The influence of pulsatile brain-tissue motion on measurements of intravoxel incoherent motion and assessment of haemodynamics using exo- and endogenous tracers

   Författare :Ronnie Wirestam; Lund Medicinsk strålningsfysik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; diagnostic radiology; cortical activation; diffusion; tumor; tumour; ischemic stroke; ischaemic stroke; tracer kinetics; bolus tracking; phase mapping; brain motion; intracranial dynamics; blood flow; haemodynamics; vascularity; MRS; perfusion; MRI; magnetic resonance; Clinical physics; radiology; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering;

   Sammanfattning : In this project, the potential of magnetic resonance (MR) imaging and spectroscopy in studies of microcirculation and haemodynamics was evaluated. The spatial and temporal characteristics of human pulsatile brain-tissue movements in healthy individuals, relevant for the understanding of the cerebrospinal-fluid (CSF) circulation and the pathogenesis of hydrocephalus, were thoroughly investigated. LÄS MER