Selective redesign

An adjustable atom or bond is one that is selected. A frozen atom or bond is one which is not selected. A partially selected atom is a selected atom, some but not all of whose bonds are selected. For such an atom, the angle between each pair of circularly contiguous frozen bonds is preserved, whereas angles to the nonfrozen bonds are adjusted and optimized relative to the frozen bonds. 

A ring cannot normally be redrawn unless all its constituent bonds are selected, because most SDG programs treat rings as irreducible units. Selecting fewer bonds is therefore nonsensical. One sensible response is to ignore such 

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Figure 10 Selective redesign the ring atom is selected in the first example but not the second.

The set of atoms and bonds to redraw (see preceding section on Selective Redesign)... 

Selective redesign capability. This subject has not been broached in the literature, although it is apparent that a few commercial drawing packages support it. (ChemWindow, ChemDraw, and ChemSketch do ISIS/Draw 2.1 does not.)... 

Drawing modes besides de novo selective redesign PMM, RMBA,... 

Selective redesign. The user can select a portion of the structure for redesign. 

Selective redesign improved, beginning with clearly defining what it means to redraw an individual atom or bond (see earlier section on Selective Redesign). 

If pressure drop is too high, reselect and redesign unit, making parallel units to reduce flow rate (and coefficient hi ), or select a larger pipe, reducing mass rate G, and hence hj. Recalculate the pressure drop. 

The model was then solved for the total refinery network and the PVC petrochemical complex. As shown in Table 5.4, the proposed model redesigned the refinery network and operating policies and also devised the optimal production plan for the PVC complex from all available process technologies. The model selected gas oil, an intermediate refinery stream, as the refinery feedstock to the petrochemical complex as opposed to the normally used light naphtha feedstock in industrial practice. In fact, this selection provided the optimal strategy as the light naphtha stream was used instead in the gasoline... 

More in line with the predictive use of hazards analysis, however, is the experimental and theoretical assessment that the viscosity of the liquid significantly affects this mode of initiation. Such information allows redesign of the process to eliminate handling of low viscosity liquid explosives, and quantitative measurement of the sensitivity of the system to mild shocks as a function of viscosity may allow the optimum level to be selected. This is not necessarily a new concept, only quantified in a different manner. Thirty years ago transporters of neat nitroglycerine in the oil fields were paid 25 a day. The stipend for transporting jellied nitroglycerine was seven dollars, a practical comment on the understood difference in hazard. 

S-selectivity toward 1-phenylethanol [35]. Several other hydrolases have also been redesigned by protein engineering to invert or enhance their enantioselectivity [36-40]. 

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