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Title: New Methodology For Use in Rotating Field Nuclear MagneticResonance

Abstract

High-resolution NMR spectra of samples with anisotropicbroadening are simplified to their isotropic spectra by fast rotation ofthe sample at the magic angle 54.7 circ. This dissertation concerns thedevelopment of novel Nuclear Magnetic Resonance (NMR) methodologies basedwhich would rotate the magnetic field instead of the sample, rotatingfield NMR. It provides an over of the NMR concepts, procedures, andexperiments needed to understand the methodologies that will be used forrotating field NMR. A simple two-dimensional shimming method based onharmonic corrector rings which can provide arbitrary multiple ordershimming corrections were developed for rotating field systems, but couldbe used in shimming other systems as well. Those results demonstrate, forexample, that quadrupolar order shimming improves the linewidth by up toan order of magnitude. An additional order of magnitude reduction is inprinciple achievable by utilizing this shimming method for z-gradientcorrection and higher order xy gradients. A specialized pulse sequencefor the rotating field NMR experiment is under development. The pulsesequence allows for spinning away from the magic angle and spinningslower than the anisotropic broadening. This pulse sequence is acombination of the projected magic angle spinning (p-MAS) and magic angleturning (MAT) pulse sequences. This will be useful to rotating field NMRbecause there are limits on how fast a fieldmore » can be spun and spin at themagic angle is difficult. One of the goals of this project is forrotating field NMR to be used on biological systems. The p-MAS pulsesequence was successfully tested on bovine tissue samples which suggeststhat it will be a viable methodology to use in a rotating field set up. Aside experiment on steering magnetic particle by MRI gradients was alsocarried out. Some movement was seen in these experiment, but for totalcontrol over steering further experiments would need to bedone.« less

Authors:
 [1]
  1. Univ. of California, Berkeley, CA (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
918641
Report Number(s):
LBNL-62766
R&D Project: 508601; BnR: KC0203010
DOE Contract Number:
AC02-05CH11231
Resource Type:
Thesis/Dissertation
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; NMR Probes rotating magnetic fields

Citation Formats

Jachmann, Rebecca C. New Methodology For Use in Rotating Field Nuclear MagneticResonance. United States: N. p., 2007. Web. doi:10.2172/918641.
Jachmann, Rebecca C. New Methodology For Use in Rotating Field Nuclear MagneticResonance. United States. doi:10.2172/918641.
Jachmann, Rebecca C. Mon . "New Methodology For Use in Rotating Field Nuclear MagneticResonance". United States. doi:10.2172/918641. https://www.osti.gov/servlets/purl/918641.
@article{osti_918641,
title = {New Methodology For Use in Rotating Field Nuclear MagneticResonance},
author = {Jachmann, Rebecca C.},
abstractNote = {High-resolution NMR spectra of samples with anisotropicbroadening are simplified to their isotropic spectra by fast rotation ofthe sample at the magic angle 54.7 circ. This dissertation concerns thedevelopment of novel Nuclear Magnetic Resonance (NMR) methodologies basedwhich would rotate the magnetic field instead of the sample, rotatingfield NMR. It provides an over of the NMR concepts, procedures, andexperiments needed to understand the methodologies that will be used forrotating field NMR. A simple two-dimensional shimming method based onharmonic corrector rings which can provide arbitrary multiple ordershimming corrections were developed for rotating field systems, but couldbe used in shimming other systems as well. Those results demonstrate, forexample, that quadrupolar order shimming improves the linewidth by up toan order of magnitude. An additional order of magnitude reduction is inprinciple achievable by utilizing this shimming method for z-gradientcorrection and higher order xy gradients. A specialized pulse sequencefor the rotating field NMR experiment is under development. The pulsesequence allows for spinning away from the magic angle and spinningslower than the anisotropic broadening. This pulse sequence is acombination of the projected magic angle spinning (p-MAS) and magic angleturning (MAT) pulse sequences. This will be useful to rotating field NMRbecause there are limits on how fast a field can be spun and spin at themagic angle is difficult. One of the goals of this project is forrotating field NMR to be used on biological systems. The p-MAS pulsesequence was successfully tested on bovine tissue samples which suggeststhat it will be a viable methodology to use in a rotating field set up. Aside experiment on steering magnetic particle by MRI gradients was alsocarried out. Some movement was seen in these experiment, but for totalcontrol over steering further experiments would need to bedone.},
doi = {10.2172/918641},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}

Thesis/Dissertation:
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  • High-resolution NMR spectra of samples with anisotropicbroadening are simplified to their isotropic spectra by fast rotation ofthe sample at the magic angle 54.7 circ. This dissertation concerns thedevelopment of novel Nuclear Magnetic Resonance (NMR) methodologies basedwhich would rotate the magnetic field instead of the sample, rotatingfield NMR. It provides an over of the NMR concepts, procedures, andexperiments needed to understand the methodologies that will be used forrotating field NMR. A simple two-dimensional shimming method based onharmonic corrector rings which can provide arbitrary multiple ordershimming corrections were developed for rotating field systems, but couldbe used in shimming other systems as well.more » Those results demonstrate, forexample, that quadrupolar order shimming improves the linewidth by up toan order of magnitude. An additional order of magnitude reduction is inprinciple achievable by utilizing this shimming method for z-gradientcorrection and higher order xy gradients. A specialized pulse sequencefor the rotating field NMR experiment is under development. The pulsesequence allows for spinning away from the magic angle and spinningslower than the anisotropic broadening. This pulse sequence is acombination of the projected magic angle spinning (p-MAS) and magic angleturning (MAT) pulse sequences. This will be useful to rotating field NMRbecause there are limits on how fast a field can be spun and spin at themagic angle is difficult. One of the goals of this project is forrotating field NMR to be used on biological systems. The p-MAS pulsesequence was successfully tested on bovine tissue samples which suggeststhat it will be a viable methodology to use in a rotating field set up. Aside experiment on steering magnetic particle by MRI gradients was alsocarried out. Some movement was seen in these experiment, but for totalcontrol over steering further experiments would need to bedone.« less
  • This study investigates the applicability of using continued free word association and factor analysis to identify, select, and organize content for use by curriculum developers. Analysis resulted in a hierarchical arrangement of concept clusters, graphically depicting the cognitive knowledge possessed by a sample of individuals knowledgeable in various phases of Power and Energy Technology (PET). Instrumentation used for data collection consisted of 1) a Stimulus-Word Generation task, 2) two forms of a Word-Association Instrument (WAI), and 3) a Validation Questionnaire. Raw data were response words elicited from 33 participants through continued free word association to 79 stimulus-words administered in themore » WAI's. Data analysis was performed by first pooling all response-words for each stimulus-word across participants forming 79 response-word distributions. Estimates of reliability for the WAI/data collection process and the data analysis procedure; and an evaluation of the face validity of the PET hierarchical structure and WAI/data collection procedure from this study are congruent with findings of previous research on this topic. The methodology used in this study seems a feasible alternative to traditional methods of identifying, selecting, and organizing content. By utilizing a sample of experts currently engaged in the topic area under investigation, the resulting content hopefully will be more accurate, up-to-date, and relevant to society's needs.« less
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  • The problem of bulk power system reliability evaluation is considered and two distinct approaches to this problem are presented. The reliability of a bulk power system is defined as the probability of the set of states for which the DC load flow constraints are satisfied with a particular demand and there is no equipment overload. One approach to this problem, presented in the first part of the dissertation, is that of obtaining a characterization and then probability calculation of the set of working states. The power system reliability model using the DC load flow does not satisfy the fundamental assumptionmore » of reliability coherency. Thus a simple characterization of the set of working states does not exist.It is shown that for a limited class of networks, namely parallel structure systems coherency is guarenteed. By introducing the concept of subminimal path and subminimal cut some of the results in Reliability Theory are generalized to noncoherent systems. In the second part of the dissertation a new approach to the problem of bulk power system reliability evaluation is presented. The approach does not require the solution of a DC load flow, though it is incorporated into the model, and is independent of the assumption of coherency. In this approach, the original equations of the DC load flow in the form of the Kirchhoff laws and the branch flow-angle relations are used.« less