NMR imaging and microscopy

Some of the most successful methods of nuclear magnetic resonance used in the study of disordered porous media have been reviewed and their applications to the measurement of pore size distribution, diffusion coefficients and permeability have been presented. This is the case of nuclear relaxation and pulsed field gradient method of a specific imbibed solvent in various fully or partially saturated organic or inorganic porous media. The cases of narrow and large distributions of pores have been 

Guillot, A. Trokiner, L. Tarrasse and H. Saint James, J. Phys. D (Appl. Phys.) 22 (1989) 1646-9. 

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Because NMR imaging constitutes a very broad area from human studies to animals, microscopy, and solids, there are many specialized books in the field. We mention two that include good discussions of many aspects of the techniques NMR in Physiology and Biomedicine edited by Robert Gillies134 and Principles of NMR Microscopy by Paul Callaghan.135 About 20% of the articles in the Encyclopedia of NMR relate to NMR imaging and to in vivo spectroscopy. All aspects of the technology, as well as many applications to biomedicine and to studies of solid materials, are included. 

For a manufacturer the difficulty is to estimate future developments or trends in NMR microscopy. Based on dedicated laboratory-made hardware developed by the NMR microscopy users and on their requests for new commercial hardware and software, the following topics could become more important micro-coil applications, multiple receiver systems and multi-coil arrangements, NMR microscopy at very high magnetic fields, MAS imaging and localized 1H MAS spectroscopy and localized single-shot 2D spectroscopy. There are no clear-cut distinctions between most of the individual topics, as will be discussed in the following sections. 

B. M. Altura and B. T. Altura, Role of magnesium and calcium in alcohol-induced hypertension and strokes as probed by in-vivo television microscopy, digital image microscopy, optical spectroscopy, P-NMR spectroscopy and a unique magnesium ion-selective electrode. Alcohol. Clin. Exp. Res., 1994,18,1057-1068. 

Microscopy electron, light (with video enhancement), scanning tunneling, atomic forces, IR microscopy, NMR imaging, thermal and magnetic domain microscopy. 

In addition to elucidation of molecular structures, NMR can also extract valuable information about physicochemical parameters. Because of the omnipresence of protonated solvents in CE/CEC, mobile-phase events can be monitored with NMR. Early studies using E-NMR involved the calculation of diffusion coefficients, electrophoretic mobilities, and viscosity [27]. Stagnant mobile-phase mass transfer kinetics and diffusion effects [60] and fluid mass transfer resistance in porous media-related chromatographic stationary phases [61] have been studied with NMR spectroscopy. NMR imaging of the chromatographic process [62] and NMR microscopy of chromatographic columns [63] have also been reported. Several applications of NMR to on-line studies of CE/ and CEC/ NMR are highlighted. 

Loren, N., Hagslatt, H., Nyden, M., and Hermansson, A.M. (2005). Water mobility in heterogeneous emulsions determined by a new eombination of confocal laser scanning microscopy, image analysis, NMR diflusometry and finite element method simulation. J. Chem. Phys. 122, 024716... 

Two classic studies on polymorphic systems are worthy of note here. One is the difference in the reactivity of the and y-polymorphic forms of meta substimted cinnamic acids 6-XL, in which the instantaneous rates and product distributions varied with time (Hadjoudis et al. 1972). A second example involves the compound 6-XLin (Voght et al. 1963) that has been shown to exist in a number of different crystalline modifications. A chloroform solvate (Schaeffer and Marsh 1969) is reactive towards oxygen, while Bruckner et a/. (1971) have reported the structure of an inactive form. The ability to probe the details of the reactions at the gas-solid interface with atomic force microscopy (Kaupp et al. 1996) and in the bulk by NMR imaging (Butler et al. 1992) has led to increased understanding and renewed interest in these systems that have considerable industrial promise especially due to the avoidance of solvents that otherwise would require disposal or recycling (Dittmer 1997). 

ID, 2D and 3D experiments, all H, and Sn chemical shifts for four postulated Sn species could be resolved unambiguously. Variable temperature and variable stress NMR spectroscopic and imaging studies are reported for a sample of high impact polystyrene. NMR microscopy and solid state stray field imaging studies indicated that imposed stress affects the molecular chain dynamics only of the polybutadiene region and not of the polystyrene(PS) matrix.The principal values of the chemical shift tensors and the separated-local field pattern are reported for the all-... 

Water Absorption, Transport Process of Water. An NMR microscopy study has been performed to measure the imbibition of water into natural cork, extractives-free cork and de-suberized cork. It was clearly indicated that suberin is the key constituent which determines the ability of cork to resist water uptake. Hydrates were generated in synthetic sediments in a laboratory cell. After hydrate formation took place and the sediments were solidified, the samples were investigated both visually and by use of H NMR imaging. 

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