Dynamic amplification effects

Effects of nuclear dynamics on electron tunneling in redox proteins have been an important question for the biological electron transfer community. While it has been understood how nuclear dynamics controls the Pranck-Condon factor, little was known until now about how the dynamics affects the tunneling matrix element. Our results show that, when tunneling is dominated by a single pathway tube, dynamical effects are small and Pathways level calculations provide reasonable results. The situation changes when several pathway tub are important and destructive interference exists among them. In this case dynamic amplification becomes important,... 

Refined studies supported by numerical analyses and/or physical testing should be carried out for specific layout configurations typical examples are the grouping effects among cooling towers, dynamic amplification of tall and slender stacks or, in the case of aircraft crash, the dynamic interaction effects on large and flexible slabs. 

After some optimization of the cycle time (time between replenishment of 60), effective amplification of the best binding peptide could be achieved. After seven cycles (112 hours), a 100-fold selectivity for the dipeptide derived from 60a and 60d could be observed over the next best binder, a remarkable result given that the ratio of binding constants is only 2.3 1. This selectivity is far higher than that typically observed in DCLs, and is based in part on the iterative nature of the experiment, an approach first demonstrated with success by Eliseev in abiotic dynamic systems [40,41]. 

So far, we have discussed several models for ee amplification. The irreversibility of the dynamical system is essential to make the final state dependent on the initial condition. In this section, we consider the effect induced by intro-... 

Chiral amplification phenomena of sergeants and soldiers and majority rule effects, which are characteristic features for dynamic helical polymers [4,58], are, therefore, observed for the noncovalent helix induction in the poly(phenylacetylene)s. For example, when 28 was mixed with 50% ee of 2-amino-1-propanol in DMSO, the complex showed an intense ICD like that of 100% ee. In the presence of a small amount of (R)-39, 28 showed a very weak ICD due to the lack of a single-handed helical conformation. However, the coaddition of the excess bulky, achiral 1-naphthylmethylamine 40 with... 

Recently, Bernard et al. [499] studied oscillations in cyclical neutropenia, a rare disorder characterized by oscillatory production of blood cells. As above, they developed a physiologically realistic model including a second homeostatic control on the production of the committed stem cells that undergo apoptosis at their proliferative phase. By using the same approach, they found a local supercritical Hopf bifurcation and a saddle-node bifurcation of limit cycles as critical parameters (i.e., the amplification parameter) are varied. Numerical simulations are consistent with experimental data and they indicate that regulated apoptosis may be a powerful control mechanism for the production of blood cells. The loss of control over apoptosis can have significant negative effects on the dynamic properties of hemopoiesis. 

Figure 6. Amplification of resistance in a 3 year period as a function of fitness in the off years (fm = l) and seed bank dynamics. A 1 on 2 off rotational scheme is used and the on herbicide has a fixed selection pressure of a = 10 (effective kill = 90 %).

A theoretical analysis of Eq. (13.6) provides the domains of control, i.e. the ranges of delay time and amplification in the feedback loop for which the control is effective. These results are in a good correspondence with the numerical simulation of the ensemble dynamics with different neuron models used for the description of individual units (Bonhoefer - van der Pol or Hindmarsh-Rose equations [21], Rulkov map model [42]). 

Snowball effect designates the situation in which small variations of a flowsheet variable, generally a flow rate at the inlet or outlet of a process with recycles, generates large variations of streams around some units inside the process (Fig. 13.7). It is worthy to note that snowball is essentially a steady state effect, and not a dynamic one, because at finite disturbance the amplification remains finite. However, some units cannot tolerate large fluctuations in flows, particularly the distillation columns. Therefore, the designer should avoid snowball effects already at the conceptual stage. 

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