Scanning electron microscopy oxide

Occasionally, especially in the developmental phase of catalyst research, it is necessary to determine the oxidation state, exact location, and dispersion of various elements in the catalyst. Eor these studies, either transmission electron microscopy (TEM) or scanning electron microscopy (SEM) combined with various high vacuum x-ray, electron, and ion spectroscopies are used routinely. 

In this paper, TiCU was oxidized in the flow reactor at various temperature and gas flow rate. The wall scales were characterized by scan electron microscopy and X-ray diffraction. The effects of reactor wall surface state, radial growth of scale layer and reactor axial temperature distribution on scaling formation were discussed. At the same time, the mechanism of scaling on the reactor wall was explored furthermore. 

The feasibility of synthesizing oxovanadium phthalocyanine (VOPc) from vanadium oxide, dicyanobenzene, and ethylene ycol using the microwave synthesis was investigated by comparing reaction temperatures under the microwave irradiations with the same factors of conventional synthesis. The efficiency of microwave synthesis over the conventional synthesis was illustrated by the yield of crude VOPc. Polymorph of VOPc was obtained ttough the acid-treatment and recrystallization step. The VOPos synthesized in various conditions were characterized hy the means of an X-ray dif actometry (XRD), a scanning electron microscopy (SEM), and a transmission electron Microscopy (TEM). 

The four doped tungsten oxide catalysts (noted above) were synthesized and used in this study. The catalysts were analyzed by scanning electron microscopy (SEM), x-ray difBaction (XRD), and electron... 

Scanning electron microscopy shows the cement to consist of zinc oxide particles embedded in an amorphous matrix (Smith, 1982a). As with the zinc phosphate cement, a separate globular water phase exists since the cement becomes uniformly porous on dehydration. Porosity diminishes as the water content is decreased. Wilson, Paddon Crisp (1979) distinguish between two types of water in dental cements non-evaporable (tightly bound) and evaporable (loosely bound). They found, in the example they examined, that the ratio of tightly bound to loosely bound water was 0-22 1-0, the lowest for all dental cements. They considered that loosely bound water acted as a plasticizer and weakened the cement. 

FIGURE 4.8 Scanning electron microscopy (SEM) cross-sections of AISI430 coupons after 300 h of oxidation at 800°C in air under different exposure conditions (a) both sides exposed to air and (b) on the air side of the air/(H2 + 3%H20) exposures [154]. 

X-ray diffractograms (Fig. 4) and petrographic analyses (scanning electron microscopy also used for estimating the surface roughness and micro-heterogeneity of samples) indicate the presence of diverse silicates and oxides on the surface and in the bulk of the vitrocrystalline samples. In addition to the nearly ubiquitous quartz, other minerals were found in several samples gehlenite, albite, diopside, portlandite, pyroxenes... 

The consolidated titanate waste pellets are similar in appearance to their glass counterparts, i.e., both are dense, black and apparently homogeneous. Microscopic analyses, however, reveal important differences between these two waste forms. While little definitive work has been done with glassy waste forms, it is apparent that several readily soluble oxide particulates of various nuclides are simply encapsulated in the glass matrix. The titanate waste form has undergone extensive analyses which includes optical microscopy, x-ray, scanning electron microscopy, microprobe, and transmission electron microscopy (l ) The samples of titanate examined were prepared by pressure sintering and consisted of material from a fully loaded titanate column. Zeolite and silicon additions were also present in the samples. 

Figure 13.11—Scanning electron microscopy (SEM) accompanied by X-ray fluorescence analysis. Secondary electron image of a cross-section of a supraconducting polycrystalline ceramic with oriented grains of oxide BiPbiSriCaiCurO, (Philips instrument, model XL30FEG). Energy emission spectra corresponding to the matrix and to a 5 pm-long inclusion (bottom). It should be noted that it is possible with this technique to obtain the composition at a precise point on the sample (Link-Oxford analyser) (study by V. Rouessac, reproduced by permission of CRISMAT. University of Caen).

Bond failure may occur at any of the locations indicated in Fig. 1. Visual determination of the locus of failure is possible only if failure has occurred in the relatively thick polymer layer, leaving continuous layers of material on both sides of the fracture. The appearance of a metallic-appearing fracture surface is not definite proof of interfacial failure since the coupling agent, polymer films, or oxide layers may be so thin that they are not detectable visually. Surface-sensitive techniques such as X-ray photoelectron spectroscopy (XPS) and contact angle measurements are appropriate to determine the nature of the failure surfaces scanning electron microscopy (SEM) may also be helpful if the failed surface can be identified. 

The mineralogical composition of Sahara dust particles shows the predominance of aluminosilicates (clays). Illite is also present in many cases while quartz particles are rare. Scanning Electron Microscopy (SEM) results on dust composition transported over different regions in the Mediterranean Basin have shown that Al-rich clay minerals such as illite and kaolinite are very common in PM10 for Cypms and dominant for Crete. Dust particles are also very rich in calcium which is distributed between calcite, dolomite and sulphates and Ca-Si particles (e.g. smectites) whereas iron oxides are often detected [43]. 

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