Microscopic techniques, useful

When the first edition was published in 1992, the resolution of the acoustic microscope techniques used at the time was controlled by the wavelength. In practice the frequency-dependent attenuation of the acoustic wave in the coupling fluid sets a lower limit to the wavelength, and therefore to the resolution, of about 1 pm for routine applications. Since then scanning probe techniques with nanometre scale resolution have been developed along the lines of the atomic force microscope. This has resulted in the development of the ultrasonic force microscopy techniques, in which the sample is excited by... 

A broad overview of traditional methods and recent developments in experimental positron spectroscopy is presented. A discussion of the generation and detection of positrons and their annihilation radiation is followed by a survey of techniques used for positron lifetime measurement, Doppler broadening spectroscopy and angular correlation of annihilation radiation, and the opportunities presented by combining these methods (e.g. in age-momentum correlation) and/or extending their capabilities by the use of monoenergetic positron beams. Novel spectroscopic and microscopic techniques using positron beams are also described. 

Figure 3. Electron microscopic techniques used to study micromechanical processes in polymers (a) investigation of fracture surfaces by SEM (b) investigation by TEM of ultrathin sections prepared from deformed and selectively stained bulk material and (c) deformation of samples of different thicknesses (bulk, semithin, and ultrathin)9 using special tensile stages with SEM, HVEM, and TEM. The technique in (c) shows the possibility of conducting in situ deformation tests in the electron microscope.

Confocal Microscopy A microscopic technique used to produce three-dimensional images of specimens that actually have considerable depth. A series of shallow depth-of-field image slices through a thick specimen are obtained. The three-dimensional image is then obtained by reconstruction so that no out-of-focus elements contribute to the final image. 

Although particulate methods are potentially more informative than bulk methods because of the extra information obtained on particle size, their application in coal mineralogy has been relatively limited The main reason for this has been the lack of automation, as such microscopic measurements are time-consuming and tedious if sufficient data have to be generated manually Recently, however, the application of microcomputers and image-analysis systems to microscopy has progressed to the extent that most of the operation, data collection, and analysis can now be done automatically A number of reports of such automated microscope techniques used in coal research have appeared recently in the literature (3-8) ... 

TABLE 2.2 Comparison of Light Microscopic Techniques Used for Characterizing Biomedical Specimens ... 

Webpages from Botany online, describing the basic microscopical techniques used in biology... 

Tracz, E. and Leboda, R. 1985. A microscopic investigation of the surface of carbon-silica adsorbents. 11. Relationships between the type of information obtainable about the surface and the microscopic techniques used for its examination. J. Chromatogr. 364 364—368. 

The SEM is often the first or second (after an optical microscope) technique used to provide a magnified image of an area of the sample to be examined. It is often used in conjunction with an ancillary analytical technique, such as EDS, to provide elemental analysis capability to go with the imaging. 

Table 5.10. Overview of microscopical techniques used in polymer/additive analysis ...

Microscopic technique used to determine the relative amount of gelatinized versus native starch granules (starch granules show the Maltese cross). 

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