Spacial resolution

Gadella, T. W. J., Jovin, T. M. and Clegg, R. M. (1993). Fluorescence lifetime imaging microscopy (FLIM) Spacial resolution of microstructures on the nanosecond time scale. Biophys. Chem. 48, 221-39. 

Fig. 4.61. Stacking of MCPs to increase gain. From left single MCP, Chevron plate, and z-stack configuration. Note the loss of spacial resolution upon stacking.

Of interest for the study of dissociation reactions is the product translational energy and the spacial resolution of the bolometer. Suppose that a molecular beam consisting of monomers and dimers is directed onto a bolometer. If a loosely bound dimer absorbs an IR photon with an energy in excess of its dissociation limit, it will dissociate with some of the excess energy released as translational energy of the two products. If the dissociation imparts sufficient translational energy normal to the beam... 

First measurements of the electrostatic double-layer force with the AFM were done in 1991 [9, 10]. The electrostatic double layer depends on the surface charge density (or the surface potential) and the ionic strength. A brief introduction to the theory of the electrostatic force is given in Chap. 4. The electrostatic double-layer force is in many cases responsible for the stabilization of dispersions. An AFM experiment can be regarded as directly probing the interaction between a sample surface and a colloidal particle (or the AFM tip). Since the AFM tip is relatively small, this interaction can be probed locally. The lateral spacial resolution can be of the order of few nanometers. 

Pressure is such a profoundly important variable in propellant and explosive applications that we have attempted not only to understand its effects, but to use it to advantage to uncover relationships between the parent molecular structure and decomposition, and to probe physicochemical processes. Because the temporal resolution of the interferometer and the spacial resolution of the IR beam precluded observation of differences in the gas product compositions at pressures above 1000 psi, we conducted all studies of the effect of pressure on thermolysis with pressures in the 1-1000 psi range. 

Fourier transform IR (FTIR) spectroscopy is a powerful analytical technique capable of yielding high quality information with a spacial resolution as low as 10 microns. 

Frantz P, Agrait N and Salmeron M 1996 Use of capacitance to measure surface forces. 1. Measuring distance of separation with enhanced spacial and time resolution Langmuir 12 3289-94... 

Ruzicka ei al. [57,58] developed some peculiar reflectance flow-through biosensors based on a sensing microzone accommodating an enzyme and an acid-base indicator (both in immobilized form) where spacial and temporal resolution of the biochemical and chemical reaction or the reversible separation of hydrogen ions was therefore impossible. The pH sensors developed by these authors (see Section 3.5.1.1) can be regarded as precedents for these reflectance sensors. The sensing approach used relies on... 

Figure 2. The ligand common to all molybdenum and tungsten enzymes, MPT, is shown here in several formats (a) in common stick notation (b) as a ball and stick (c) an orientation rotated 90° from view (b) to emphasize the spacial relationship between the pterin plane and the dithiolene-pyran ring portion (d) MGD in common stick notation and for comparison, (e ) FAD, a common electron-transfer prosthetic group. Coordinates for the views in (b) and (c) are taken from the data deposited in the Protein Data Bank (PDB) for the 1.3-A resolution structure of DMSO reductase from Rhodobacter sphaeroides.

The composition of these nanozones can be easily determined in STEM mode by placing the electron probe exactly on a particular nanozone for EELS analysis. The advantage of using EELS in spot analysis is that the high resolution STEM probe (2 angstrom diameter) may be used. This provides a very precise spacial analysis and also allows us to analyze extremely narrow nanozones as in this case for the thin dark layer. An example of this work is provided in Figure 5 where the STEM-derived nanozone model is illustrated... 

TEM is a very common analytical technique that can produce high resolution photographs of nanoparticles in polymer matrices. This technique can yield accurate information on the level of exfoliation, the distance between partieles, and the spacial distribution of nanoparticles. Figure 3.4 contains the TEM image of a well-exfoliated composite of montmoril-lonite in nylon 6. The clay plates appear as dark lines in a light gray matrix. The teehnique can also yield pictures of tactoids and disordered structures mentioned previously when discussing X-ray diffraction. 

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