Ammonium electron micrograph

Figure 6.8 Scanning electron micrographs of magnesium ammonium phosphate mortar III (Abdelrazig, Sharp El-Jazairi, 1989) (a) after 1 hour, low magnification, (b) after 1 hour, high magnification showing needle-like and cuboid crystallites.

Figure 6.11 Scanning electron micrographs showing the microstructure of a cement formed from magnesium oxide and ammonium hydrogenphosphate solutions (Sugama Kukacka, 1983b).

Figure 5. Electron micrographs of xanthan sample F (A), and D (B) obtained from replicas of xanthan vacuum dried from solutions containing 0.1 mM ammonium acetate, 50 % glycerol and 3-10 ug /ml polymer. Specie designation I = single-stranded, II = perfectly matched doublestranded, III = branching from double- to single-stranded. Scale bar = 200 nm.

Fig. 11A-C. Scanning electron micrographs of fused silica capillary surfaces etched with methanolic ammonium hydrogen difluoride solution. (Reprinted with permission from [78], Copyright 2000 Elsevier). Etching process was carried out for A 3 h at 300 °C B, 2 h at 300 °C and 2 h at 400 °C C 2 h at 300 °C and 1 h at 400 °C...

Figure 15.6A Scanning electron micrographs (SEM) of fractured surfaces of (a) TPS-natural MMT nanocomposite containing 9.8 wt% clay, and (b) TPS-NH4MMT nanocomposite containing 10.7 wt% clay, (c) is the enlarged image for (b) showing spontaneously formed regular foam structures with 84% porosity in TPS-ammonium-treated clay.

A mixture consisting of aniline ( 0.2 g) and (lS)-(+) camphorsulfonic acid (3.48 g) was dissolved in 10 ml of water and then treated with five separate portions of 0.1 g of ammonium peroxydisulfate dissolved in 1 ml water. Each successive portion was added when the solution turned from blue to green while the reaction mixture was maintained at 20°C. After the additions were completed the mixture was centrifuged and the product washed with water. The circular dichroism spectrum of the product suspensed in water indicated a molar ellipticity of about 90 x 103 deg-cm2/dmol. Transmission electron micrographs showed that the product had a nanofibrous structure with fiber diameters from 30 to 70 nm and had a length of several hundred nanometers. 

Fig. 3. Electron micrographs of negatively stained aggregates of E. coli pyrophosphatase in 1.4 M ammonium sulfate. The objects in (a), (b), and (c) were stained with sodium silicotungstate (4 g/100 ml) at pH 7, 6, and 5, respectively. The forms in (d) were stained with uranyl acetate (2 g/100 ml) at pH 4.

Most surface area determinations are based on measurements of the low temperature adsorption of nitrogen or krypton on the solid and use of the BET theory. This procedure may not give reliable results because the products are chilled well below reaction temperature, possibly resulting in the sealing of internal pores. Volumes of gases adsorbed are sometimes small, as observed for dehydrated alums [37] and decomposed ammonium perchlorate [48], where the areas are consistent with product crystallites of linear dimensions between 1 and 3 pm. The results indicate, however, that little, if any, zeolitic material is formed [36]. The surface area of a solid may also be estimated from electron micrographs. Density measurements may be used to complement area measurements. 

Electron micrographs of aerosol particles collected on membrane Alters under remote maritime conditions (photo A. Meszaros). (a) sea salt (b) ammonium sulfate (c) sulfuric acid (d) mixed. The size of the field in the pictures is 2.4 x 3.6 /tm. (By courtesy of J. of Aerosol Science)... 

Fig. 3.37. Electron micrographs of Pb02 aggregates treated with ammonium acetate after 6h of formation. Inner parts of aggregates have dissolved to form channels. Magnification bar (a) 10 gm (b) 1 rm [49].

An Interesting phenomenon was observed with these immobilized cells. When the immobilized E. coZ-i cells were suspended at 37°C for 24-A8 hours in substrate solution, its activity Increased 10 times higher. The Increase of enzyme activity was observed even in the presence of chloramphenicol, inhibitor of protein synthesis. Therefore, this activation was considered not to be the result of protein synthesis but to be due to Increased permeability caused by autolysis of E. CoZi cells in the gel lattice. This was also confirmed by the electron micrographs of immobilized E. CoZi cells, which indicated that lysis of cells had occurred. Even when lysis of the cells did occur, the aspartase could not leak out from the gel lattice, but the substrate, ammonium fumarate, and the product, L-aspartate, passed easily through the gel lattice. 

Figure 10. Scanning electron micrograph of a cross-section (top) of a diquaternary ammonium cellulose prepared by reaction of a DEAE cellulose (2.57% N) with dllodopentane and exchanged to thiocyanate form (100% conversion) and EDAX (bottom) showing distribution of s throughout fiber.

Electron micrographs of Pb02 aggregates, treated with ammonium acetate, after 6 h of formation. 

FIGURE 15.15 Transmission electron micrograph of iron(III) oxide deposited on silica. The catalyst has been prepared by impregnation of sUica with ammonium iron(III) citrate, drying, and calcination, (a) The very uniform distribution of tiny iron oxide erystallites is apparent, (b) At a more elevated magnification, the small size of the iron oxide particles is evident. 

Figure 1. Electron micrograph of xanthan from a fermentation broth (Pfizer Flocon 4800) diluted in 100 mM ammonium acetate (A), and powdered xanthan (Kelco Kelzan XCD) in 2 mM ammonium acetate (B). Scale bar = 200 nm. 

Figure 2. Electron micrograph of welan in 100 mM ammonium acetate. Scale bar = 200 nm. 

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