Plant Structure Abstraction

The heat transfer characteristics of the model are simulated via heat structures. Heat structures are one-dimensional abstract components used to represent the solid mass of the reactor plant. The one dimension is in the radial direction, perpendicular to the direction of fluid flow. Heat transfer in the axial direction (parallel to fluid flow) is represented by using several fluid volumes in the axial direction and connecting a heat structure to each. TRACE heat structures also permit two-dimensional conduction in Cartesian, cylindrical or spherical geometry. Conduction, convection, and radiation heat transfer modes can all be represented with heat structures. Heat structures, with their associated boundary conditions and neutron kinetics calculations, provide the ability to link thermal conditions among the plant structural, fuel (power components), coolant, and ambient environment (radiation enclosures). 

To achieve these consistencies, MODEL.LA. provides a series of semantic relationships among its modeling elements, which are defined at different levels of abstraction. For example, the semantic relationship (see 21 1), is-disaggregated-in, triggers the generation of a series of relationships between the abstract entity (e.g., overall plant) and the entities (e.g., process sections) that it was decomposed to. The relationships establish the requisite consistency in the (1) topological structure and (2) the state (variables, terms, constraints) of the systems. For more detailed discussion on how MODEL.LA. maintains consistency among the various hierarchical descriptions of a plant, the reader should consult 21 1. 

Usuda H (1995) Phosphate deficiency in maize. V. Mobilization of nitrogen and phosphorus within shoots of young plants and its relationship to senescence. Plant Cell Physiol 36 1041-1049. doi http //pcp.oxfordjournals.org/cgi/content/abstract/36/6/1041 van der Heijden MGA, Boiler T, Wiemken A, Sanders IR (1998a) Different arbuscular mycor-rhizal fungal species are potential determinants of plant community structure. Ecology 79 2082-2091... 

Before a species is analyzed with respect to its flavonoid content, knowledge about earlier reports on the chemistry and flavonoid distribution within the genus and related species may be of value. The most exhaustive source for such information is Chemical Abstracts, and excellent reviews on structures and distribution of flavanoids have been compiled regularly.Several reviews have recently addressed the general field of flavonoid analysis.Among the earlier reviews in the field, we will particularly recommend consulting Techniques of Flavonoid Identification by Markham and Plant Phenolics by Harborne. References to review articles on specific spectroscopic techniques applied on flavonoids will be cited under the various spectroscopic methods covered in this chapter. Spectroscopic information of importance is also presented in several other chapters in this book. 

Voila. Lef s try to get all that information together into a single modest package and make it available to the chemists and botanists who might want it. Should it be a review article in Chemical Reviews or the Journal of Natural Products Several factors said "No." Most botanical review surveys are not searchable except by taxon name (that would assume that you would know the plant from which it came) or by some complex and maddening Chemical Abstracts entry that dealt with some alphabetization that demanded the knowledge of the structure and the way the structure would be listed. And most review articles also insist on a tidy format that is without editorial comment and does not contain volunteered ideas and extrapolations. 

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