Imaging MRI technique

Up to this point, water mobility values obtained are average values for an entire sample. However, if magnetic field gradients in the x, y, and z directions are incorporated into a pulsed NMR experimental setup, the spatial distribution aspects of water mobility (7), T2, and D) can also be measured via the use of magnetic resonance imaging (MRI) techniques. 

In this article, magnetic resonance imaging (MRI) technique is described as a diagnostic tool for in-situ visualization of water content in the membrane under fuel cell operation.7-30 Demonstrative applications and measurement procedure using MRI techniques are presented with discussion on water transport involved in PEMFCs. 

Chapters 4-6 address specific diagnostic methods in PEFCs. Martin et al. provide a detailed review of methods for distributed diagnostics of species, temperature, and current in PEFCs in Chapter 4. In Chapter 5, Hussey and Jacobson describe the operational principles of neutron radiography for in-situ visualization of liquid water distribution, and also outline issues related to temporal and spatial resolution. Tsushima and Hirai describe both magnetic resonance imaging (MRI) technique for visualization of water in PEFCs and tunable diode laser absorption spectroscopy (TDLAS) for measurement of water vapor concentration in Chapter 6. 

Magnetic resonance imaging (MRI) Technique that creates a high-resolution, three-dimensional image of the brain (Chapter 3). 

Recently, magnetic resonance imaging (MRI) technique has been applied for the measurement of liquid... 

NMR imaging (MRI) techniques were developed in the 70s mainly in the medical and biological fields, using essentially the H nucleus but also He, F, P, and more recently hyperpolarized Xe nuclei, etc. 

Some information can be obtained on porous media from conventional NMR spectroscopy, and this is discussed in Section 2. Relaxation time measurements have been widely used to characterize porous solids, and this technique is discussed in Section 3. Pulsed field gradient (PFG) methods may be used to probe the local structure of the pore space and to characterize transport within it, and these are discussed in Section 4. Magnetic resonance imaging (MRI) techniques can also be used to characterize the pore space and to measure transport, and applications are discussed in Section 5. The bulk of this review will be concerned with mesoporous and macroporous materials, as it is for these systems that NMR is particularly useful in characterizing the pore space. However, some applications of NMR techniques to probe the pore space and transport within microporous materials will be mentioned in Section 6. Finally, some general conclusions are given in Section 7. 

A novel magnetic resonance imaging (MRI) technique, chemically selective NMR imaging, which resolves the separate components of the evolving vertical concentration profiles of 3-component non-colloidal suspensions, is described. This methodexploits the sensitivity of MRI to chemical differences between the three phases to directly image the fluid phase and one of the solid phases, with the third phase obtained by subtraction. 

K.W. Feindel, Magnetic resonance imaging (MRI) techniques for polymer electrolyte membrane and direct alcohol fuel ceU characterization, in C. Hattnig, C. Roth (Eds.), Polymer Electrolyte Membrane and Direct Methanol Fuel Cell Technology, In Sim Characterization Techniques for Low Temperature Fuel Cells, vol. 2, Woodhead Publishing Limited, Cambridge, UK, 2012. 

The review deals with applications of magnetic resonance imaging (MRI) techniques to study flow. The principles of flow measurement by MRI are first briefly discussed and give examples of some applications, such as multiphase flows, the MRI rheology of complex fluid flows, and blood flows in the human body. 

In many studies, the simultaneous use of multiple techniques (CARS, THG, TOF, Raman, etc.) helps to localize secondary metabolites and/or lipophile molecules such as the triterpenoids and phytoalexins. There are also numerous other imagery techniques which could prove useful for localizing the specialized metabolites and/or lipids in situ. Thus, the Magnetic Resonance Imaging (MRI) technique has already shown its capacity to furnish images of lipid distribution in intact organisms with a 10 pm order of resolution. 

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