Surface coils

C—Surface Coil Type Condenser, Intercondenser and Aftercondenser N—Signifies no condenser in the series. 

The factors that can affect the rate of heat transfer within a reactor are the speed and type of agitation, the type of heat transfer surface (coil or jacket), the nature of the reaction fluids (Newtonian or non-Newtonian), and the geometry of the vessel. Baffles are essential in agitated batch or semi-batch reactors to increase turbulence which affects the heat transfer rate as well as the reaction rates. For Reynolds numbers less than 1000, the presence of baffles may increase the heat transfer rate up to 35% [180]. 

Yet such an approach would be hampered by self-cancellation due to phase averaging of the NMR signal by integration over r. A solution would then be the use a surface coil whose receptivity is confined to a limited number of propagation wavelengths, i.e., for low wave frequencies and/or high velocities. 

Dry matter 2 FID, fruit moving over surface coil at 0-250 mm/s 37... 

Maturity ( ) 2 FID spectrum with surface coil, speeds up to 300 mm/s 51... 

Fig. 9. Schematic of the NMR-MOUSE. Samples are placed on top of the surface coil located between the two permanent magnets.

K.M. Hoard, Measurement of Flow Rates Using Surface Coil Nuclear Magnetic Resonance Vol. MSc. University of Arlington, Arlington, 1989. 

R.P. Mason, R.L. Nunnally, P.P. Antich, Tissue oxygenation A novel determination using F surface coil spectroscopy of sequestered perfluorocarbon emulsion, Magn. Reson. Med. 18 (1991) 71-79. 

Little cardiac P MRS has been reported in animal models. Lee et al. describe methods for measuring myocardial energetics using surface-coil... 

T. Morimoto, T. Qbata, T. Qhno, Y. Suzuki, H. Ikehira, T. Suhara, S. Furukawa, H. Tsujii and T. Nakano, Phosphorous-31 magnetic resonance spectroscopy of cervical cancer using a transvaginal surface coil. Magn. Reson. Med. Sci., 2005, 4,197-201. 

Figure 7.2 Generation of spatial resolution in NMR (a) Conventional NMR imaging with magnetic field gradients. A magnetic field gradient Gx in x0 direction (top) converts the NMR spectrum (bottom) of an object (middle) into a projection of the object, (b) Localization of NMR signals from a large object by use of a surface coil...

Fluorine-19 NMR spectroscopy has been used to study biological systems in a number of ways. Structural information can be obtained if the fluorine is used as a probe, for example as part of an amino acid in a protein. Biochemical pathways can be elucidated by observing the fluorine-19 chemical shifts of products and intermediates which are usually well separated owing to the wide chemical shift range. Finally, the distribution of fluoro-organic molecules within an organism can be detected using such techniques as surface coils. 

Fluorine-19 NMR has also been used to examine the fate of anesthetics in vivo. Figure 9 shows the spectra of two anesthetics in rabbit brain using a surface coil. The 70-Hz geminal fluorine-proton coupling is well resolved, however, the smaller fluorine-proton vicinal couplings are not resolved owing to the large line widths obtained by this technique. 

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