Search for dissertations about: "Spin diffusion"

Showing result 1 - 5 of 73 swedish dissertations containing the words Spin diffusion.

2. 1. Nuclear Magnetic Resonance for Diffusion Imaging Development and evaluation of spin-echo-based pulse sequences for in vivo studies of water self-diffusion

   Author : Sara Brockstedt; Lund Medicinsk strålningsfysik; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; perfusion fraction; electrocardiographic triggering; segmented EPI SEPI ; echo-planar imaging EPI ; fast spin-echo FSE ; spin-echo SE ; navigator echoes; phase corrections; diffusion; Magnetic resonance; MRI; ischaemic stroke; Medicine human and vertebrates ; Medicin människa och djur ;

   Abstract : The interest in diffusion imaging with nuclear magnetic resonance techniques has increased during the last few years. The main reason is the possibility of early diagnosis of acute ischaemic stroke, at a time when conventional MR techniques and computerised tomography fail. READ MORE

4. 2. Developing novel diffusion MRI methods for comprehensive analysis of restricted and anisotropic self-diffusion system

   Author : Hong Jiang; Fysikalisk kemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; MRI; diffusion; tissue microstructure; heterogeneity; diffusion encoding; q-vector; ;

   Abstract : Diffusion MRI is a non-invasive imaging technique used to study the microstructural properties of biological tissues by observing the self-diffusion of water molecules. Traditional diffusion MRI methods, based on the pulsed gradient spin-echo sequence, employ magnetic field gradients to encode information about translational motion. READ MORE

5. 3. NMR diffusion studies on lyotropic liquid crystalline systems

   Author : Greger Orädd; Frank Volke; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Diffusion; pulsed field gradient; liquid crystalline systems; lipid lateral diffusion; cubic phases; peptide-lipid interactions; hydrophobic mismatch; permeability;

   Abstract : The pulsed field gradient fourier transform nuclear magnetic resonance (PFG-FTNMR) method to measure translational diffusion coefficients in multicomponent systems has been applied to amphiphilic molecules forming liquid crystalline phases.By analyzing the concentration dependence of the diffusion coefficients of water and amphiphile in a micellar system of N,N-dimethyldodecy lamine oxide (DDAO) in water it was possible to conclude that the micelles formed were polydisperse in size and shape. READ MORE

6. 4. Diffusion MRI of Small Ischemic Brain Lesions: Technical aspects, clinical experiences and diagnostic criteria

   Author : Bo Geijer; Lund Diagnostisk radiologi; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiology; Clinical physics; Metastasis; ADC; b; Infarct; MRI; Ischemia; Diffusion-Weighted; Diffusion; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering;

   Abstract : Purpose: To compare the visualization of small ischemic brain lesions using diffusion using diffusion-weighted (DW) MRI and conventional imaging, with special regard to diagnostic efficiency. Imaging features of lesions of different ages, diagnostic limitations and technical principles were also investigated. READ MORE

7. 5. Superdiffusive Spin Transport and Ultrafast Magnetization Dynamics : Femtosecond spin transport as the route to ultrafast spintronics

   Author : Marco Battiato; Olle Eriksson; Hardy Gross; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ultrafast magnetisation dynamics; anomalous diffusion; femtosecond dynamics; magnetism; Materialvetenskap; Materials Science;

   Abstract : The debate over the origin of the ultrafast demagnetization has been intensively active for the past 16 years. Several microscopic mechanisms have been proposed but none has managed so far to provide direct and incontrovertible evidences of their validity. READ MORE