Time chemical maps

In Section II.3 we have seen that a specific chemical species existing in a given physicochemical environment is characterized by specific values of 7) and T2, and that this fact is important both in the implementation of imaging pulse sequences to obtain quantitative information and in the modification of the pulse sequences to image selectively one species and/or phase within the sample. While exploitation of relaxation time contrast is not likely to become a routine approach for chemical mapping in reactors, there will be niche applications in which it will continue to have use—three of these are identified below. The limitations of the approach derive from that fact that the relaxation times characterizing a system will not only be influenced by chemical composition but also by temperature and the proximity of the molecules to a solid surface or interface. The three case studies illustrated below in which relaxation time contrast has been used with considerable success are (i) an... 

The AIREYE SLAR will have a 200-kW transmitter vs. 45 kW in AOSS. It will also have a dry film silver radar processor instead of a wet chemical processor. It will be the primary oil pollution detection sensor, detecting slicks by reduction of ocean clutter from 2-25 miles on both sides of the aircraft and providing a near-real-time annotated map. 

Figure 6. Infrared-NSOM image of a blended polystyrene/polyethylacrylate film ( 1 micron thick) on Si. The image (8 /xm X 8 /xm), collected at 3125 cm b shows the domains of polystyrene (PS) embedded within the polyethylacrylate (PEA). This chemical map of the surface has 10 times higher spatial resolution than a conventional optical infrared microscope image. (Courtesy of Dr. Chris Michaels and Dr. Stephan Stranick, NIST.)...

Primarily models chemical releases to the air. Includes a chemical database and map editor and is capable of mapping concentration isopleths. Allows real-time meteorological data input. 

Analytical electron microscopy (AEM) can use several signals from the specimen to analyze volumes of catalyst material about a thousand times smaller than conventional techniques. X-ray emission spectroscopy (XES) is the most quantitative mode of chemical analyse in the AEM and is now also useful as a high resolution elemental mapping technique. Electron energy loss spectroscopy (EELS) vftiile not as well developed for quantitative analysis gives additional chemical information in the fine structure of the elemental absorption edges. EELS avoids the problem of spurious x-rays generated from areas of the spectrum remote from the analysis area. 

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