SCANNING ELECTRON Subject

This technique can be applied to samples prepared for study by scanning electron microscopy (SEM). When subject to impact by electrons, atoms emit characteristic X-ray line spectra, which are almost completely independent of the physical or chemical state of the specimen (Reed, 1973). To analyse samples, they are prepared as required for SEM, that is they are mounted on an appropriate holder, sputter coated to provide an electrically conductive surface, generally using gold, and then examined under high vacuum. The electron beam is focussed to impinge upon a selected spot on the surface of the specimen and the resulting X-ray spectrum is analysed. 

However, during the formation of a filter cake, floes must be subject to considerable disruptive forces and large aggregates may not survive. Scanning electron micrographs of filter cakes formed after various periods of slow stirring have shown no obvious differences. 

Chong et al. [742] have described a multielement analysis of multicomponent metallic electrode deposits, based on scanning electron microscopy with energy dispersive X-ray fluorescence detection, followed by dissolution and ICP-MS detection. Application of the method is described for determination of trace elements in seawater, including the above elements. These elements are simultaneously electrodeposited onto a niobium-wire working electrode at -1.40 V relative to an Ag/AgCl reference electrode, and subjected to energy dispersive X-ray fluorescence spectroscopy analysis. Internal standardisation... 

The overlays thickness estimation is possible exploiting a twin fiber placed in the same deposition chamber and subject to the same coating procedure. The coated twin fiber can be cut by a precision cleaver and analyzed by scanning electron microscopy (SEM). One of the deposited thin overlay is clearly observable in the SEM image of the fiber section reported in Fig. 3.13. 

Triplicate aliquots were taken for particle size analysis and two of those aliquots were mixed for BET surface area analysis results are in Table III. The nine samples were individually sieved for size distribution. A chi-squared test was performed on each triplicate set in order to check the apparent efficiency of composite mixing. For all three composite samples, there was a 90 percent probability that each of the three replicates from each composite sample came from the same population. The A and C samples were combined and evaluated for surface area by nitrogen adsorption (BET). The B samples were then subjected to scanning electron microscopy (SEM) analysis. 

Fig 1. Scanning electron micrographs of Gouda cheese eaten by 2 different subjects and expectorated after 5 chews. Spitout material was collected in a sieve and rinsed in cold water. Particles were spread on individual aluminium trays and frozen in liquid nitrogen prior to examination. 

Figure 4. A scanning electron micrograph showing the replicas of lacunae and canalicuh in situ in mandibular bone from a young subject aged 22 years. The inset shows enlarged lacunae identified by a rectangle. This micrograph illustrates the interconnectivity of the connected cellular network (CCN). Copied from Atkinson and Hallsworth (1983).

Optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) data obtained from the surface of metallographic section of initial alloy were compared with those from the surface subjected to hydrogen... 

There are a number of indicators of fatigue damage that have attracted interest in the literature. During the life of a component subjected to fatigue, the material can exhibit changes in modulus, permanent offset strain, shape of the hysteresis loops, and temperature rise of the specimen surface. Direct evidence of matrix crack density can be obtained by surface replication, while a more detailed analysis of microstructural damage requires scanning electron microscopy (SEM). 

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