SEMI-RARE

Fig. 38. Line excitation SEMI-RARE images of two-phase flow in a ceramic monolith rated at 200 cpsi. The signal intensity shows how far the initially excited water molecules have traveled in the period between line excitation and the image acquisition. The gas flow rate was (a) 0, (b) 100, (c) 200, and (d) iOOcin inin. Images acquired 78ms after r.f. excitation are shown. A 5mm-high slice of spins was initially excited along the direction of flow. The fleld-of-view is 50 mm (x) x 25 mm (z).

Thus, we see that in a single image acquisition, the line excitation SEMI-RARE method allows an evaluation of the extent of flow heterogeneity (up- and downflow) within the monolith. Furthermore, velocities in completely liquid field channels can be measured. This was not possible when SEMI-RARE was used because velocities were measured by following a gas-liquid interface. However, a limitation of the line excitation SEMI-RARE technique is that there needs to be a significant amount of liquid present within the monolith, because the gas phase is not imaged only liquid captured in the initial line excitation can be followed. 

All the non-archival sources cited here, except the private communications and the online document, are available at the Science Museum Library. The unpublished Annual Reports of the Science Museum and much of the published Science Museum material are kept in the semi-rare book room. In addition to these sources, I also had access to the chemistry curator s collection of gallery photographs and a set of labels with floor plans for the 1977 Gallery. 

A.J. Sederman, M.D. Mantle, L.F. Gladden, Single exdtation multiple image RARE (SEMI-RARE), ultra-fast imaging of static and flowing systems. Journal of Magnetic Resonance, 2003, 161, 15-24. 

Reciprocating compressors are available with a large variety of other drivers, which include the piston engine, steam turbine, or, in rare cases, a gas turbine. Next in popularity to the electric motor is the piston engine. The arrangement lends itself to skid mounting, particularly with the semi-portable units found in the oilfield. The unit is also popular as a lease unit, which may be lifted onto a flat bed trailer and moved from one location to another as needed. The engine is either direct-coupled or. as with smaller compressors, it may be belt-connected. 

The fresh flowers of the mignonette, Heicda odoratu, yield traces, about -002 per oeut., of an essential oil of eieecdingiy powerful odour. This oil is semi-solid at ordinary temperatures, and its cberaistnr is not uoderslood, as the oil is in itself so very rare. Indeed, commercially, -an ordinary floral extract is generally used in preferenoe to any direct... 

Lung volume reduction surgery is a rarely performed treatment option for heterogeneous emphysema patients with high hyperinflation. Novel semi-invasive and invasive alternatives are being developed, such as bronchial valves for heterogeneous emphysema treatment, and bronchial stents for homogeneous emphysema to reduce counteiproductive collateral ventilation. 

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Dean et al. (1974) use a Langmuir probe technique in a rare gas repetitive afterglow plasma. The electron temperature is extracted from the semi-log plot... 

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