Topology rotational fields

For each county in the 10 states evaluated, all cropland soil types in land capability classes (LCCs) I—VIII are identified. For each individual soil type, acres of that particular soil type, field topology characteristics (percentage low and high slopes), erodibility, and tolerable soil-loss limit are obtained from the USD A. These data are used in the rain and wind erosion equations described later. In each of the states analyzed, the following crop rotations are considered (where applicable) continuous corn, corn-soybean, corn-winter wheat, corn-spring wheat, continuous winter wheat, winter wheat-soybeans. 

The estimated quantities of removable corn stover and wheat straw presented in Tables 7 and 8 conform to intuitive expectations in that as tillage operations become less intensive (i.e., go from conventional to no-till), the amounts of removable residue increase across all rotations in all states. Differences in estimated removable quantities among states is a function of several factors including production location (whether the majority of production occurs in areas that have highly erodible soils and field topology nonconducive to removal), climatic/erosive conditions at the locations of production, and actual yields at these specific locations among others. These factors must be considered before residues can be removed at any specific location. 

Successive high-resolution AMRO experiments shown in Fig. 4.39 verified the proposed FS in an impressive way [376]. As mentioned in Sect. 3.3, 0-(ET)2l3 was one of the first compounds where AMRO, i. e., resistance oscillations periodic in tan (9, were observed [258]. These results, which were reproduced later [377], are understood by the warped FS model explained above. The period of the oscillations is related to the Fermi wave vector via (3.18). In the experimental data shown in Fig. 4.39 not only the previously reported fast AMROs but also slow ones (indicated by small dashes) were observed [376]. The insets of Fig. 4.39 show the peak numbers of the (a) fast and (b) slow oscillation frequency vs tan O. From the slopes for different field rotation planes fcr(0) could be constructed. The resulting two ellipsoidal FSs are in good agreement with the proposed topology of Fig. 4.37c with respect to both form and area. 

For example. Fig. 2 shows a SchHeren texture, which is typical of nematic distortions of the director field (visible as dark branches usually named brushes). These distortions are induced by the perpendicular anchoring on the microscope slide of topological defects, called disclination lines, which are numbered from 1 to 7 in Fig. 2. These disclination lines can be classified into two groups according to their local topology as the dark brushes seen around these defects can rotate either clockwise or counterclockwise as the crossed polarizers are rotated simultaneously while the sample is kept fixed. This is due to the two different possible defect topologies illustrated in Fig. 2 for cases 1 and 2 [1]. 

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