Importance Calculations

Two IBM-PC interactive codes calculate importances and risk and allow the operator to investigate the effects of system and component failures on the risk and importance. The BNL code NSPKTR models the Indian Point Plants 2 and 3 using information in their PSAs. NSPKTR uses 

PRISIM embodies the IREP model of Arkansas 1. It includes extensive grapitivs of. simplified flow diagrams and relevant operating history from LERs (Licensee Event Reports required by Regulatory Guide 1.16) The plant model consists of 500 cutsets truncated by probabilities determined from normal operation. 

Postprocessing cutset information such as cutset acronyms and cutset searches is performed by REPORT (BNL written to aid in preparation of NUREG/CR-4207). A standard output format for the fault tree codes would facilitate postprocessing, 

Iman and Shortencarrier is a unique code for processing cutset information in matrix form. 

This matrix method is both flexible and computationally convenient. It can handle complemented events. such as required for event trees as well as distributions by simply 

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Importance - calculates and displays three importance measures, Fussell-Ve.scly, Risk Reduction Ratio, Risk Increase Ratio, for each event in the system, sequence, or end state. 

Uncertainty Analysis determines the effects on the overall results from uncertaintic.s in the database, assumptions in modeling, and the completeness of the analysis. Sensitivity analyses determine the robustness of the results importance calculations are useful for identifying and prioritizing plant improvements. 

I am particularly indebted to Dr. Howard Lambert of Lawrence Livermore Laboratory and FfA Associates for providing the PC computer codes FTAP (fault ti ee code), POSTER (post processor), IMPORT (importance calculation), MONTE (Monte Carlo error determinadoni, and supporting documentation and instructions. 

Frequencies computed with methods other than Hartree-Fock are also scaled to similarly eliminate known systematic errors in calculated frequencies. The followng table lists the recommended scale factors for frequencies and for zero-point energies and for use in computing thermal energy corrections (the latter two items are discussed later in this chapter), for several important calculation types ... 

There are several important calculations that are needed to properly evaluate and select the appropriate positive displacement pump [17,18,19,20,21]. 

At Novartis, so-called BioavailabiUty Radar Plots [44] are used to visually display the oral absorption potential of molecules. On these plots five important calculated descriptors (log P, molecular weight, PSA, number of rotatable bonds and water solubility score [45]) are displayed on the axes of a pentagonal radar plot and compared with predefined property limits (green area) which were determined by the analysis of marketed oral drugs. These plots provide an intuitive tool that displays multiple parameters as a single chart in a straightforward but informative way, providing visual feedback about the molecule s bioavailabiUty potential (Fig. 5.5). 

The most important calculated and experimental monomer data, such as equilibrium distances, dipole moments, polarizabilities, and the harmonic vibrational frequencies of the dihalogens XY, are reported in Tables 1-4. 

Changing grams to moles and moles to grams is perhaps the most important calculation you will have to make all year (Fig. 4-2), Some authors use the term molar mass for the mass of 1 mol of any substance. The units are typically grams per mole. 

We studied the structure and PES of betaines II for the model compounds (+)Me3E15-CH2-E14Me(2 ) (E14=Si, Ge, Sn E15 = P, As). The most important calculated geometric parameters for these betaines are presented in Table XVI. In them the E14-C bonds in the E14-C-E15 fragment are much longer than the E14-Me bonds. This difference in lengths... 

One can estimate the maximum free radical concentration and, more important, calculate the number of crosslinks formed and chain scissions occurring for any particular time period of irradiation. These estimates are based on known or estimated G values for radical formation, crosslinks, or scissions. The G value is the magnitude of a particular reaction occurring per 100 e.v. of energy absorbed—e.g., G(scission) is the number of scissions that take place per 100 e.v. absorbed. G( crosslink) may be obtained from the sol-gel data presented earlier, while values of G(scission) and G(radicals) may be estimated from values in the literature—e.g., see (4). The former value may also be compared with established literature values—(e.g., see Ref. 14). For a 5.5-... 

In addition to being bent, in contrast lo ethylene, the Gc—Ge and Sn—Sn bonds are not as short us expected for true double bonds.11 Calculations indicate that p.,-p bonding is less important and other interactions may become increasingly important Calculated bond orders are Ge—Ge = I 61 and Sn—Sn = 1.46.w... 

In common applications EP values must be calculated over several thousand points, therefore the efficiency of the computation technique is of crucial importance. Calculation of the first term on the right-hand side of Eq. (3) is trivial, but not of the second term because of the three-center one-electron potential integrals. 

Another important calculation is that of rate of shear, which is derived from the thickness of the film in the nip and the surface speed of the rolls—due allowance being made for the expansion that takes place as the film leaves the nip. 

In the next to the last column the potential energy J of the system is given for various places on the map shown in Fig. 40. Values of J can be calculated in the same way for any position of the atoms but for the problems of chemical kinetics we are interested only in the lowest pass between the two valleys and most of the map is unnecessary. With a little experience one learns how to select only the important calculations in the neighborhood of the pass. In the example given here the many contour lines are given merely for more complete visualization of the method. 

Calculations of the vibrational contributions to the static polarizability and hyperpolarizability have also been attempted. As far as the EFISH experiment is concerned, which depends on the square of an optical frequency field, it is assumed that there will be no direct contribution to (—2static contribution is comparable with the static electronic contribution to /1(0 0,0). An indirect vibrational effect through the linear polarizability of the solvent molecules is more important. Calculations of the vibrational effects in pNA cannot be carried out reliably even for the static case since the second term in the perturbation theory is much larger then the first and there is no evidence of convergence. 

Problems on recycled wood when used as a raw material in PB production were analyzed according to the questionnaire survey from the eleven makers. Problems can be classified into eight items, and the results of the importance calculated numerically with some assumptions are shown in Figure 4. 

We will complete and document the spreadsheet in Chapter 6 after we have explored some of the important calculations of statistical analysis. For now, click on File/Save As. .. in the menu bar, enter a file name such as grav chloride, and save the Excel spreadsheet on a floppy disk or other medium for retrieval and... 

Having predicted the deposition of particles of different sizes, the Task Force calculated the predicted pattern of deposition of particles from polydisperse aerosols of known count median diameter and ag. The results of these most important calculations are shown in Table 10. The importance of this table cannot be overestimated ... 

Although these steps describe many important calculations, their usefulness is... 

In this book, the fundamentals of solution chemistry of mineral/surfactant systems and important calculations involved are systematically introduced and the influence of relevant physico-chemical conditions are discussed. Importantly, because solution chemistry is closely related to the molecular stmcture of the flotation reagents, the characteristics of such structure is also discussed in detail. 

Inclusion of spin-orbit effects at zero magnetic field is critical primarily in two arenas, structure determination of light actinides (notably Pu) [48] and certain spectroscopic characterizations. At non-zero field their inclusion is clearly more important. Calculating spin-orbit effects however raises the computational requirements by approximately an order of magnitude because one must use double-group symmetries (complex-valued KS orbitals are already possible in GTOFF, which works with Hermitian matrices rather than real-symmetric ones). Therefore, a rapid, high-accuracy approximate scheme for inclusion of spin-orbit effects has been developed [48]. 

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