Preparatory Calculations

The calculation of the chirality code starts from a molccnlar structure, requires some preparatory calculations, and follows several steps that are described in detail below. 

The chirality code of a molecule is based on atomic properties and on the 3D structure. Examples of atomic properties arc partial atomic charges and polarizabilities, which are easily accessible by fast empirical methods contained in the PETRA package. Other atomic properties, calculated by other methods, can in principle be used. It is convenient, however, if the chosen atomic property discriminates as much as possible between non-equivalent atoms. 3D molecular structures are easily generated by the GORINA software package (see Section 2.13), but other sources of 3D structures can be used as well. 

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S-13. M. Eusebi, et al, Preparatory Calculations for a New Experimental Program on Dry Aerosol Resuspension Mechanisms (STORM Project) , Proceedings of the European Aerosol Conference, Oxford, United Kingdom, 1992. 

As a preparatory calculation for the formulation of constitutive equations, we take note of the term q8VI(, h°) which corresponds to the change in electrostatic energy per unit initial volume brought about by a small perturbation of the voltage F at constant charge. This quantity can be rephrased as a function of Z)° and as —D SEP, where the minus is justified by the circumstance that the... 

After such an extensive programme of preparatory calculations, the results of the first PHEBUS-FP test (expected to be rformed in April 1993) are eagerly anticipated by all concerned. MeanwhUe, preparation of the subsequent tests is also in progress. 

A few people are working on Hylleraas type and James-Coolidge type wavefunctions of many-electron systems. Their present calculations are preparatory, but will expand enormously in the production steps. We should not forget that these calculations are most important from the basic point of view. 

During this preparation stage, analysts will frequently find that there is insufficient quantity or quality of measurements to close the material balance. Analysts should m e every effort to measure all stream flows and compositions for the actual test. They should not rely upon closing material balances by back-calculating missing streams. The material balance closure will provide a check on the vahdity of the measurements. This preparatory material balance will help to identify additional measurements and schedule the installation of the additional instruments. 

When we consider the effect that the difference of the phases of the carrier frequency of the preparatory pulse and the following pulses produces on the NQR signal, for the convenience of our calculations let us assume that (j) = 7t/2 for the preparatory pulse and 0 = 0 for the other pulses. 

Switzerland Within the framework of the CAPRA project, the fuel option for amplified plutonium consumption is being studied. In the area of materials for actinide transmutation, the following tasks has been completed in 1994 (1) preparatory experiments and solubility tests for (Ui, PUJ O2 (0.25 < x < 0.65 and for (Uj., PU,J N (0.25 < x< 0.75), as possible materials for the efficient fission of plutonium in a fast neutron flux (2) fabrication of pure PuN-microspheres for ceramic-metal fuel (3) design calculations for sphere-pac segments, based on the idea of a ceramic-metal fiiel (4) material preparation of (U, Zr) N and pelletization tests of TiN and (U, Zr)N for the irradiation experiment in the reactor PHENIX (5) experimental preparations of (Ce,U) O2, (Ce,U,Pu)02 and (Ce, PU)02 for the CAPRA core with lower Pu content, and (6) cleaning of americium from waste streams of the plutonium separation equipment (extraction chromatography). 

The treatment of basic cross-section data preparatory to the calculation of criticality by computer codes has been demonstrated to influence the results. A procedure has been developed for establishing the most appropriate broad-group neutron energy structure for criticality safety analyses from a standard 218-neutron-group structure and master cross-section library described in Ref. 2. Emphasis is being placed on a group structure for shipping cask calculations. 

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