Search for dissertations about: "Diffusion"

Showing result 6 - 10 of 2032 swedish dissertations containing the word Diffusion.

  2. 6. Applications of diffusion MRI: Tensor-valued encoding, time-dependent diffusion, and histological validation

    Author : Jan Brabec; Lund Medicinsk strålningsfysik; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; diffusion MRI; meningioma; glioma; brain tumors; intracranial tumors; undulations; restricted diffusion; time dependence; spherical b-tensor encoding; linear b-tensor encoding; histogram analysis; anisotropic kurtosis; isotropic kurtosis; hyperintensity; conspicuity; white matter; detection; diffusion spectrum; consistency; type; grade; axon diameter; axonal trajectories; Fysicumarkivet A:2022:Brabec;

    Abstract : Diffusion MRI (dMRI) sensitizes the MR signal to the diffusion of water molecules at the microscopic level and thereby non-invasively probes tissue microstructure. This is relevant when determining biological properties of tissues, for example, cancer type and its malignancy. READ MORE

  4. 7. Hydrogen in nano-sized metals : Diffusion and hysteresis effects

    Author : Wen Huang; Björgvin Hjörvarsson; Max Wolff; Gavin Walker; Uppsala universitet; []
    Keywords : Hydrogen; diffusion; hysteresis; optical technique; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : Metal hydrides can be used as hydrogen storage materials for fuel cells and batteries, and as sensors for detecting hydrogen gas. The use of metal hydrides for hydrogen storage can be hindered by poor kinetics and low capacity. Moreover, poor sensitivity, long recovery and response time, limit the applications of metal hydrides as hydrogen sensors. READ MORE

  5. 8. 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

  6. 9. Theory of Hydrogen Quantum Diffusion

    Author : Thomas Mattsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; path-integrals; isotope effect; transition state theory; quantum; diffusion; hydrogen; first-principles calculations; nickel;

    Abstract : Atomic hydrogen adsorbed on a metal surface is one of the simplest possible examples of chemisorption, yet it is very challenging. The adsorption and the very elementary process of surface diffusion, a single atomic jump, have been investigated theoretically using several methods. READ MORE

  7. 10. Investigation of Water Mobility using Diffusion-Sensitive MRI: The Role of q-Space Imaging, High b-Values and Diffusion Time

    Author : Jimmy Lätt; Lund Medicinsk strålningsfysik; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MRI; kurtosis; high b-value; diffusion; diffusion time; NMR; q-space;

    Abstract : Nuclear magnetic resonance (NMR) diffusometry provides important information about molecular motion on a microscopic scale. The advantage of NMR diffusometry is its ability to characterise microstructures non-invasively. This has made the method important not only in chemistry, biochemistry and materials science, but also in medicine. READ MORE