Electron micrograph figure

The macrostructure of the boron nitride obtained here is porous with pores 2 pm in diameter. There is no evidence for microporosity and the BET surface area 1s 35 m2 g-1. Transmission electron micrographs (Figure 4) show regions of well developed crystallinity. The crystalling grains are 5—10 nm on a side and 30-40 nm long. The BN (002) lattice fringes are clearly visible. 

Precision and Accuracy. This preliminary stage was done to estimate the ways in which particle size distributions vary and to see how far they can be utilized in practical ways. The above technique was chosen to enable us to obtain some approximate results conveniently, without elaborate sample preparation. The scanning electron micrographs (Figures 6-15) show that too great an accuracy should not be expected at this stage, especially in view of the ill-dispersed nature of the particles in some cases (Figures 7 and 10). 

Polyacrylonitrile is also quite insoluble in benzene, so that dilution of the monomer with benzene does not change the heterogeneous polymerization in any essential way. The effect of dilution on the specific surface is shown in Table III. There is a discernible trend toward lower surface areas at low acrylonitrile concentration. This is also evident in electron micrographs (Figure 2), where the particles from a benzene-acrylonitrile mixture are more compact and dense in appearance than those in Figure 1. Nevertheless, the surface is still extensive, and this has profound effects on the rate of polymerization. 

The probable explanation, I believe, is the following. The sheets of tobermorite roll into fibers, as in the electron micrograph (Figure 7). This rolling of the sheets plus the aggregation of the fibers create spaces into which nitrogen cannot penetrate but water can. This is not merely because of the difference between the sizes of the molecules, but also because the tobermorite surface is strongly hydrophylic. 

Figures 2a, 2b, 2c, and 2d represent the morphology of the 25/75 (PC-PST) blend. PST forms the continuous phase and the dispersed spherical PC particles show some aggregation (Figure 2a). From the transmission electron micrographs (Figures 2b and 2c) it can be seen that small PST particles are present in the dispersed PC phase. Examination of the etched fracture surface by scanning electron microscopy reveals depressions of completely removed PC particles as well as spheres with dark periphery because of partial hydrolysis of PC (Figure 2d).

ABS and HIPS. The yield stress vs. W/t curves of ABS and HIPS are very similar. They are somewhat surprising because the yield stresses reach their respective maximum values near the W/t (or W/b) where plane strain predominates. This behavior is not predicted by either the von Mises-type or the Tresca-type yield criteria. This also appears to be typical of grafted-rubber reinforced polymer systems. A plausible explanation is that the rubber particles have created stress concentrations and constraints in such a way that even in very narrow specimens plane strain (or some stress state approaching it) already exists around these particles. Consequently, when plane strain is imposed on the specimen as a whole, these local stress state are not significantly affected. This may account for the similarity in the appearance of fracture surface electron micrographs (Figures 13a, 13b, 14a, and 14b), but the yield stress variation is still unexplained. 

Similarly the electron micrographs (Figures 11c and lid) show the existence of microgels even before gelation (darker phase) in the size range from 30 nm to 100 nm. 

Scanning electron micrographs (Figures 2 and 3) of the Immobilized bacteria clearly show the mass of rod-llke viable bacteria in the process of cell-division on the surface of the plastic. This proves Immobilization of a considerable amount of bacteria on the soft PVC surface as they have not become detached from the surface even during preliminary treatment required for electron microscopy. No bacteria could be detected, on the other hand, on the surface of less suitable plastic beds. 

The deposition of the enzyme was very site-specific as shown in the scanning electron micrograph. Figure 5. This photo illustrates the enzyme layer deposited on top of the electrode only in the region where the top insulation layer was removed. This deposition of the enzyme only on the working electrode minimized the amount of glucose oxidase wasted and thus minimized the production costs. 

The observed decline in cleaning and net permeate flux with backpulsing over time was studied by Mores and Davis [27]. They showed that prolonged filtration with recycle of retentate to the feed reservoir (such as done in batch concentration) leads to cell rupture. The ruptured cell debris and contents are adhesive and cause irreversible membrane fouling. Scanning electron micrographs (Figure 2.22) show that a slime layer forms on the membrane surface, but is absent when the retentate is not recycled to the feed reservoir. Mores and Davis [27] used DVO to... 

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