Octagonal complex

Like Adena mounds, Hopewell mounds are conical, but some are also dome-shaped. They average 20-30 ft (6-9 m) high and are often found in clusters enclosed by artificially constructed ridges that may be circular, square, or octagonal. Mounds often were part of large social and religious complexes built on elevated areas, usually near a river valley. Because of their enormous size, their construction often required hundreds of workers, who laboriously scooped the earth with clamshell hoes and large animal bones and then carried it back to the mound in baskets and skin aprons. Many of these workers may have been women. 

Apart from hexagonal grids, the analysis maybe evenly applied to octagonal ones [Figure 3.8(b)]. As far as the extension of (3.88) to three dimensions is concerned, it should be stated that, despite its advanced discretization characteristics, total complexity is greatly increased. This is the reason for the relatively limited use of such lattices, especially in waveguide problems where their merits would be indeed fairly instmctive. 

A FIGURE 12-18 Nuclear pore complex, (a) Nuclear envelopes microdissected from the large nuclei of Xenopus oocytes visualized by field emission in-lens scanning electron microscopy. Top View of the cytoplasmic face reveals octagonal shape of membrane-embedded portion of nuclear pore complexes. Bottom V ew of the nucleoplasmic face shows the nuclear basket that extends from the membrane portion, (b) Cut-away model of the pore complex. [Part (a) from V Doye and E. Elurt, 1997 Curr. Opin. Cell Biol. 9 401 courtesy of M. W. Goldberg and I D. Allen. Part (b) adapted from M. R Rout and J. D. Atchison, 2001, J. Biol. Chem. 276 16593.]... 

Octametallic complexes, 162 cube,162 dicubanc, 163 [MsXf,l core, 162 planar octagon, 162 tetracapped tetrahedron, 163 Optica) isomerism cobalt ammines, 12 history, 180... 

Figure 8 (A) Isolated rat liver nuclear envelope, negatively stained with ammonium molybdate. Note the pronounced electron-transparent octagonal annuli of the nuclear pore complexes. (B) A partly purified nuclear pore complex fraction obtained by Triton X-100 extraction and ultrasonication of nuclear envelope, followed by sucrose density gradient centrifugation. Bars = 200 nm.

A stUl higher degree of complexity is exhibited in the fabrics used in polymer matrices. Woven fabrics, which are formed by interlacing threads or yams, usually have the yams oriented octagonally to each other and therefore exhibit maxima in tensile modulus in these directions, but may, as in the case of tiiaxially and tridimensionally woven fabrics, have more than two directions of orientation. Knitted fabrics are formed by the intermeshing of loops of yarn they are generally more... 

---