Sökning: "low NMR frequencies"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden low NMR frequencies.

1. 1. Nuclear Magnetic Relaxation in Micellar Solution and Lyotropic Liquid Crystals. Tools and Applications

   Författare :Ruslan Sitnikov; KTH; []
   Nyckelord :NMR; NMR relaxation dispersion; NMR spectrometer; low NMR frequencies; NMR duplexer; NMR preamplifier; NMR lock; surfactant systems; micellar solutions; lyotropic liquid crystals; cubic mesophase;

   Sammanfattning : Structurally, this Thesis is divided into two parts thatdescribe (i) the hardware development for NMR relaxationstudies and (ii) its applications for studies of the surfactantsystems.The developed hardware solutions allow to expand thefrequency range covered by conventional NMR spectrometers tomake NMR experiments feasible at resonance frequencies down to100 kHz. LÄS MER

3. 2. Exploiting Prior Information in Parametric Estimation Problems for Multi-Channel Signal Processing Applications

   Författare :Petter Wirfält; Magnus Jansson; Abdelhak Zoubir; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Array signal processing; covariance matrix; damped sinusoids; direction of arrival estimation; frequency estimation; Kronecker; NQR; NMR; parameter estimation; persymmetric; signal processing algorithms; structured covariance estimation; Toeplitz; Array; signalbehandling; kovariansmatris; dämpad sinus; riktningbestämning; frekvensskattning; Kronecker; NQR; NMR; parameterestimering; persymmetrisk; algoritm; strukturerad kovariansmatris; Toeplitz;

   Sammanfattning : This thesis addresses a number of problems all related to parameter estimation in sensor array processing. The unifying theme is that some of these parameters are known before the measurements are acquired. LÄS MER

4. 3. Radio Frequency Systems for NMR Imaging: Coil Development and Studies of Non-Thermal Biological Effects

   Författare :Lars Malmgren; Lunds universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anechoic chamber; TEM transmission cells; FDTD; circularly polarized electromagnetic fields; reduced coupling; noise matching; matching networks; low noise amplifiers; upper thoracic spine; surface coils; Nuclear magnetic resonance; magnetic resonance imaging; non-thermal biological effects; blood-brain barrier; Electronics; Elektronik;

   Sammanfattning : This thesis concerns both design and optimization of NMR imaging systems and studies on non-thermal biological effects of electromagnetic fields. These two research fields are linked together by the fact that humans are subject to static and pulsed magnetic fields as well as to magnetic radio frequency fields (RF) during an NMR imaging investigation. LÄS MER

5. 4. Conformational studies of carbohydrates: MD simulation and NMR spectroscopy

   Författare :Robert Pendrill; Lena Mäler; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis describes various aspects of conformational studies of carbohydrates, from development of the methods by which experimental parameters are gathered to the application of NMR spectroscopy and MD simulation for the analysis of a disaccharide. Paper I describes the use of site-specific 13C labeling as a tool to resolve spectral overlap of 1H frequencies in a trisaccharide, allowing the measurement of important crossrelaxation rates and long-range couplings which were previously obscured. LÄS MER

7. 5. Fabrication and noise properties of high-Tc SQUIDs with multilayer superconducting flux transformers

   Författare :Maxim Chukharkin Leonidovich; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; YBCO; High-Tc SQUIDs; SQIFs; ulf-NMR; SQUID magnetometers;

   Sammanfattning : The thesis describes the development of highTc superconducting quantum interference devices (SQUIDs) with multilayer thin film flux transformers. High-Tc SQUID magnetometers are promising in various biomedical applications, including magnetoencephalography (MEG) and ultra-low field magnetic resonance imaging (ulf-MRI). LÄS MER