Ring-shaped

A number of particles perfonn periodic rotations in a ring-shaped contamer with a small opening, through which some particles can escape. Two situations can now be distinguished. 

The catalyst combines two essential ingredients found in eadier catalysts, vanadium oxide and titanium dioxide, which are coated on an inert, nonporous carrier in a layer 0.02- to 2.0-mm thick (13,16). Other elements such as phosphoms are also used. Ring-shaped supports are used instead of spherical supports to give longer catalyst life, less pressure drop though the reactor, and higher yields (17,18). Half rings are even better and allow more catalyst to be loaded (18). 

The various ring-shaped peUets also have greater resistance to dust fouling. Ring catalysts also have somewhat higher activity per unit volume than peUet... 

The oxychlorination reaction is very exothermic and the catalyst is very active, which makes it necessary to mix the catalyst with an inert diluent to avoid overheating in a fixed-bed reactor. A low surface area, spherically- or ring-shaped alumina or chemical porcelain body can be used as a diluent with the ring-shaped catalyst. The density of the inert material should be similar to the catalyst to avoid segregation during loading, and the size should be slightly different to allow separation of the inert material from the spent catalyst. 

The Vibro-Energy (Sweco, Jnc.), a vertical vibratory mill (Fig. 20-40) has a mill body in a ring-shaped trough form but uses horizontal vibrations at a frequency of about 20 Hz of the contained media, usually alumina spheres or cylinders. Other characteristics appear in Table 20-19. 

Fig. 21 12 Steel ring-shaped cathode in the heati ng chamber of a caustic evaporator.

The external heating boxes for the caustic soda evaporator with forced circulation must be anodically protected separately. Ring-shaped impressed current electrodes of carbon steel are mounted and insulated on supporting brackets (see Fig, 21-12). 

Ring-shaped ground, band width b, radius... 

Ring-shaped nuclear fusion research reactor Tokamak 15 at the Kurchatov Institute, Moscow, Russia. (Photo Researohers Ino.)... 

It is easily seen that for given m there exists only one ring-shaped C-graph with m vertices. The construction described in Sec. 37 defines a topologically unique C-H graph For a given m there exists with respect to structure exactly one purely ring-shaped cycloparaffin. It is, in the simplest case w 3, the above (Secs. 56 - 58) discussed cyclopropane. 

Generalizing properly what we have discussed for the case w = 3, we can establish the group of the structure formula of the only purely ring-shaped it has degree 2m and order 2m 2 and... 

In order to set up the generating function of the homologues of the purely ring-shaped we substitute the generating function r(x)... 

This modular concept allows for the synthesis of monodisperse dendritic phen-ylene dendrimers of the first (43a, 22 benzene rings) and second (43b, 62 benzene rings) generation [65]. Due to the dense packing of the phenylene rings, shape-persistent nanostructures result. Several of these large phcnylene-type dendrimers (e.g. 43a) can be further cyclized to giant polycyclic PAHs. 

In the case of a ring-shaped domain D (Fig. 6-7) bounded by two closed curves Gx and 02 (e.g., circles), it is sufficient for the existence of, at least, one cycle that ... 

The conformation, i.e. the (approximate) spatial arrangement of the ring atoms of a monosaccharide in the cyclic form, may be indicated by an italic capital letter designating the type of ring shape, and numerals, distinguishing the variants. The... 

Ring fusion methods, 145-146 Ring shape, notation, cyclic monosaccharides, 69 Ring size, cyclic monosaccharides, 59... 

At a given flow condition, different flow patterns were observed which can be classified into five distinct patterns depending on the interfacial configuration liquid alone (or liquid slug), gas core with a smooth thin liquid film, gas core with a smooth thick liquid film, gas core with a ring-shaped liquid film, and gas core with a deformed interface. 

Gong, Y., Hu, Z., Chen, Y, Huang, H. and He, X. (2005) Ring-shaped morphology in solution-cast polystyrene-poly(methyl methacrylate) block copolymer thin films. Langmuir 21, 11870-11877. 

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