Percentage overshoot

Overshoot The first maximum excursion of a pulse beyond the 100% level Overshoot is the portion of the pulse that exceeds its defined level temporarily before settling to the correct level. Overshoot amplitude is expressed as a percentage of the dehned level... 

Table III. The MRCI and SOCI results are not in as good agreement with the FCI as the MRCI-hQ or SOCI+Q results. The +Q correction does not overshoot as it did for N2 and CH2, in part because of the larger number of electrons correlated here. As noted above, when only six electrons are correlated, the MRCI accounts for such a high percentage of the correlation that the +Q correction overestimates the missing correlation. For more than six electrons, or for cases where the zeroth-order wave function used is less satisfactory than was the CASSCF for N2 and CH2, the +Q correction may become a better approximation. This is especially true where quantities involving large differential correlation effects, such as electron affinities, are sought [7]. Thus the +Q correction substantially improves the agreement with FCI for the electron affinity of fluorine [8], even if large CASSCF active spaces and SOCI wave functions are employed.

End point control of a batch reaction has one outstanding character istic reset must not be used. The bulk of the reaction is conducted away from the set point-reset would try to overcome this offset and ulti mately result in overshoot. The controller should be proportional-plus-derivative, with zero bias, so that the valve is shut when the set point is reached. If the measurement is pH, reagent should be added through an equal percentage valve (without a cascade flow loop), to match the process characteristic. A system employing temperature and end-point control is shown in Fig. 10.20. 

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