Sökning: "spin relaxation"

Visar resultat 16 - 20 av 118 avhandlingar innehållade orden spin relaxation.

1. 16. Combined Quantum Mechanical and Molecular Dynamics study of paramagnetic complexes : Towards an understanding of electronic spin relaxation

   Författare :Shehryar Khan; Michael Odelius; Jozef Kowalewski; Juha Vaara; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular dynamics; quantum chemistry; zero-field splitting; kemisk fysik; Chemical Physics;

   Sammanfattning : The prime objectives of contrast agents in Magnetic Resonance Imaging (MRI) is to accelerate the relaxation rate of the solvent water protons in the surrounding tissue. Paramagnetic relaxation originates from dipole-dipole interactions between the nuclear spins and the fluctuating magnetic field induced by unpaired electrons. LÄS MER

3. 17. Water Relaxation Processes as Seen by NMR Spectroscopy Using MD and BD Simulations

   Författare :Ken Åman; Per-Olof Westlund; Arnold Maliniak; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; NMR; Stochastic Liouville Equation; Brownian Dynamics; Molecular Dynamics; Water; Relaxation; Deuterium; ESR; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi; Physical Chemistry; fysikalisk kemi;

   Sammanfattning : This thesis describes water proton and deuterium relaxation processes, as seen by Nuclear Magnetic Resonance (NMR) spectroscopy, using Brownian Dynamics (BD) or Molecular Dynamics (MD) simulations. The MD simulations reveal new detailed information about the dynamics and order of water molecules outside of a lipid bilayer. LÄS MER

4. 18. 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. 19. MRI evaluation and image processing in gel dosimetry. A study of selected MRI properties and image processing in 3D gel dosimetry

   Författare :Peter Magnusson; Malmö Medicinsk strålningsfysik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Klinisk fysiologi; medical instrumentation; tomography; radiology; Clinical physics; image registering; multi-slice; slice profile; ferrous sulphate; polyacrylamide; 3D volume acquisition; RF field; B1 field; relaxation time; T1; T2; spin-echo; multi-spin-echo; stochastic noise; nonuniformity; SNR; radiologi; tomografi; medicinsk instrumentering; Radiopharmaceutical technology; Radiofarmaceutisk teknik; Physics; Fysik;

   Sammanfattning : Gel dosimetry is a new dosimetry method applied in radiation therapy. Gel dosimeters consist of a radiation sensitive gel, which can integrate absorbed doses from several radiation sources or beams. The dose to the gel can be evaluated by magnetic resonance imaging (MRI), a procedure that is the focus of the present thesis. LÄS MER

7. 20. 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