Spirals interacting

Eig. 18. Cycle of downward spiraling performance with unmanaged process interactions. 

If spiral growth occurs due to the existence of screw dislocations, the results depend upon whether the diffusion length ijy is smaller or larger than the typical separation of the spiral arms i. In the first case the situation hardly changes from the purely kinetic situation without diffusion, but in the second case interaction between steps comes into effect [90] and phenomena such as step bunching [91] take place. We can estimate qualitatively the... 

Fig. 10-5 Sketch of (a) current vectors with depth characteristic of an Eckman spiral (b) relationship between wind, surface current, and net water movement vectors and (c) production of circular gyres from the net interaction of the Coriolis force and Eckman transport.

With this scenario, the system may eventually settle, but it is just as likely that the system in Fig. 10.12 will spiral out of control. It is clear that loop interactions can destabilize a control system, and tuning controllers in a MIMO system can be difficult. One logical thing that we can do is to reduce loop interactions by proper pairing of manipulated and controlled variables. This is the focus of the analysis in the following sections. 

The stability of secondary structure is also influenced by surrounding structures (Fig. 2-3). Secondary structure may be stabilized by interactions between the side chains and by interactions of the side chains with other structures in the protein. For example, it is possible to arrange the amino acid sequence of a protein or peptide into a helix that has one face that is hydrophobic and one that is hydrophilic. The helix wheel shown in Fig. 2-3 illustrates how this is possible. View the helix as a long cylinder. The peptide backbone spirals up and around the cylinder. The... 

The regular system of hydrogen bonds in DNA is destroyed in DNA/NaOH solution and the DNA molecule is partly transformed from a double spiral to a chaotic ball [118]. This transformation may promote the interaction of DNA molecules with CNTs. The ssDNA adsorption on CNTs was greater than for dsDNA molecules [117,118], suggesting that the adsorption of DNA on CNT is presumably via hydrophobic interactions between the nanotubes and the hydrophobic bases on DNA. 

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