Spiral square-shaped spirals

The process of spiral formation can be deduced from details observed by AFM, as shown in Fig. 11.12. A film of 102 nm is more than twice as thick as one lamellar thickness (about 45 nm at 57 C). Thus, the first lamella, growing close to the substrate is stUl covered with a large reservoir of non-crystalline - but crystallizable polymers. From our experiments, it turned out that the junction lines between side branches are regions of high probabihty for spiral nucleation. These spirals may either form a new lamella, similar in shape as the underlying square-shaped lamella (see Figs. 11.10 and 11.12A). Or, as shown in Figs. 11.10 and 11.12C, such spirals may be accompanied by a... 

Simple homopolymers are not the only polymeric materials capable of forming single crystals. Block copolymers of poly(ethylene oxide) crystallize in the presence of considerable weight fractions of amorphous polystyrene (see Figure 6.12) (52). In this case square-shaped crystals with some spirals are... 

Basically, the purpose of drill collars is to furnish weight on bit. However, both size and length of drill collars have an effect on bit performance, hole deviation, and drill pipe service life. Drill collars may be classified according to the shape of their cross-sections as round drill collars (conventional drill collars), square drill collars, or spiral drill collars (drill collars with spiral grooves). 

Evidence for growth spirals was observed on the 001 face and probably on the 100 face of a crystal grown by the SRL-CP method by Yamada et al. (1995b). The shape of the steps on the 001 face was found to be square and that on the 100 face was elliptical under the same supersaturation. This morphological difference was partially... 

The morphology is linked to the crystal modification, Fig. 23. The crystals with orthorhombic modification are multilayers with square and lath shape. The crystals with tetragonal and hexagonal modification have square or hexagonal habits and present spiral ramps and terraces. In the morphology of the orthorhombic modification, twinning was frequently observed when the crystals were grown at the turbidity... 

This section is devoted to numerical experiments on the motion of spiral waves as described previously, in finite systems of square and circular geometries. Both types of geometries are considered in order to investigate which properties are generic for systems of limited size and which effects are due to the particular shape of the boundaries. Moreover, two different dynamics will be considered. The oscillatory units are described either by the CGL equation of by relaxational oscillators. 

Our previous works with the open spiral flow and the square plate injection molding indicated that quite similar on the hierarchical microstructure development. However the difference in shape, size and the layer thickness affect on the impact properly. With a specific mold, the open spiral flow, with much longer flow length than typical injection mold, which is not restricted since the flow length to mold thickness ratio is over 400 [3], hence hold pressure was not apphed. 

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