Magnetic particle imaging

Weizenecker, J., Gleich, B., Rahmer, J., Dahnke, H., Borgert, J., 2009. Three-dimensional real-time in vivo magnetic particle imaging. Phys. Med. Biol. 54, LI—LIO. 

Amitay-Rosen T, Cortis A, Berkowitz B (2005) Magnetic resonance imaging and quantitative analysis of particle deposition in porous media. Environ Sci Technol 39 7208-7216 Ashton FM, Sheets TJ (1959) The relationship of soil adsorption of EPTC to oats injury in various soil types. Weeds 7 88-90... 

Figure 7.4. Optical microscopy image of permanently linked magnetic particles. Each streptavidin coated particle is linked to its neighbors by on average 3 dibiotin dsDNA of 151 base pairs. After the field has been switched off, the chains persist and spontaneonsly bend under thermal flnctnations. (From [27], with permission.)...

Magnetic resonance imaging ultimately depends on the observation that nuclear particles, including protons, neutrons and electrons, have an intrinsic rotation or spin, creating an electromagnetic field. The magnetic fields... 

Other potential applications of photonic crystals include crystals with rows of holes to guide radiation around sharp bends (something that cannot be attained with conventional optical fibres), nanoscopic lasers formed from thin films, ultrawhite pigment formed from a regular array of submicron titanium dioxide particles, radio frequency reflectors for magnetic resonance imaging (MRI) and LEDs. 

In the present volume. Gladden, Mantle, and Sederman summarize the application of magnetic resonance imaging techniques to represent both local flow fields in reactors containing solid catalyst particles and conversions within model reactors. The techniques provide a non-invasive, chemically specific measurement technique that leads to representation of a reactor over length scales ranging from Angstroms to centimeters. 

Magnetic resonance imaging (MRI) (Moudrakovski et at., 2004) Liquid, hydrate phase distribution Yes Hydrate conversion from ice particles or water droplets in oil (min) Typically 3000 psi microns Direct visualization of droplet conversion to hydrate crystallites and hydrate shells... 

Other advances in mesoscopic measurements include the application of magnetic resonance imaging (MRI) to study real-time hydrate growth from ice particles and water droplets, andparticle morphology (Moudrakovski et al., 2004). Scanning electron microscopy has also been shown to be a useful tool for studying natural... 

Figure 4. MM- image of the vertical component of a magnetic field over a small magnetic particle (the size is about 400 pm).

Magnetic resonance imaging permitted direct observation of the liquid hold-up in monolith channels in a noninvasive manner. As shown in Fig. 8.14, the film thickness - and therefore the wetting of the channel wall and the liquid hold-up -increase nonlinearly with the flow rate. This is in agreement with a hydrodynamic model, based on the Navier-Stokes equations for laminar flow and full-slip assumption at the gas-liquid interface. Even at superficial velocities of 4 cm s-1, the liquid occupies not more than 15 % of the free channel cross-sectional area. This relates to about 10 % of the total reactor volume. Van Baten, Ellenberger and Krishna [21] measured the liquid hold-up of katapak-S . Due to the capillary forces, the liquid almost completely fills the volume between the catalyst particles in the tea bags (about 20 % of the total reactor volume) even at liquid flow rates of 0.2 cm s-1 (Fig. 8.15). The formation of films and rivulets in the open channels of the structure cause the further slight increase of the hold-up. 

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