Hierarchy preservation

Figure 1.5 (a) Hierarchy of clusters of rubrene on Au l 1 1, showing the evolution from trimers to pentamers of trimers and eventually 150 molecules per cluster as a decamer of the pentamers. (b) Illustration ofthe preservation of chirality through the hierarchy. (Adapted with permission from Ref. [9]). 

The Solar System, in comparison, offers two lines of evidence to constrain the timescale for the lifetime of the proto-solar nebula and the epoch of planetesimal formation. On one side, relatively unaltered chondritic components preserve traces of their chemical and thermal history on the other side, dynamical information is imprinted on the hierarchy of the Solar System. 

Quite often, a synthesis tool might automatically preserve the hierarchy of a large datapath operator. For example,... 

In this case, a synthesis tool may preserve the 16-bit adder as a separate hierarchy. 

Fourcroy was keenly aware, then, of the limitations of the princi-palist approach to composition embedded in the phlogiston theory. Not only did he point out the mismatch between the supposed presence of phlogiston and the manifested properties of the bodies containing it he also explicitly criticized the Stahlian hierarchy of composition as a mere imagination. Instead, he wished to introduce a classification of chemical experience based on affinities. In other words, he sought to work out the affinity approach to composition in chemical systematics. This is why he later fought to preserve the doctrine of elective affinities in opposition to Berthollet. Although historians have interpreted Fourcroy s work as a contribution to the study of composition, his works should be placed within the framework of affinity chemistry which called for a new order of chemical composition and systematics. 

Complex Refinement Structures. Flowsheets are refined across various hierarchical abstraction levels and depicted in specific representation formats. In the context of the IMPROVE project, we are mainly interested in two of the three commonly used flowsheet variants the abstract flow diagram (AFD) and the process flow diagram (PFD). Thus, the flowsheet editor supports the full hierarchy of complex stepwise refinement operations from AFD to PFD and assures a set of consistency constrains in order to preserve their semantic correctness. 

The organization of this chapter preserves the hierarchy of topics generally followed in the applied mathematics hterature. However, the reader is encouraged to refer to Table 2.1 for general guidelines on what chemical engineering activity would lead to each of the itemized sections. 

Certain groupings of secondary structure elements, including the segments of polypeptide chain that connect these structural elements, occur in many globular proteins and are termed motifs or supersecondary stmctures (Figure 5.7). The motifs are a higher level of organization that preserves the structure hierarchy. These are ... 

Aspects of such management practices are likely to appear in all vertical relationships in the project hierarchy, from the chief executive of the corporation that owns the plant down through the project team and sub-contractors. A responsible party tends to hold those reporting or sub-contracting to him accountable in detail, while attempting to preserve the maximum of flexibility of performance target for himself. ... 

Within a systems hierarchy [Faulkner 2002, Storey 2003], data is exchanged across external interfaces, and across internal interfaces. In such a hierarchy, data may be used within several layers. Each system component may use this common data in a different context and hence re-used data may be also attributed a subtly different meaning for each usage. The layered model [Faulkner 20021 allows the visualisation of the extent of the influence of these data structures, data elements or data items. This visualisation may identify a requirement for validation at an interface to preserve the integrity of one or more safety functions. 

After the Bible, the Homeric poems occupied the premier place in the Byzantine hierarchy of Uterature. As we saw in Chapter One, the Iliad preserved at the close of Book 22 the passage best known among educated Byzantines as the typos of an orphan s suffering. Achilles had just slain Hector and the Greeks were dragging the body of the fallen Trojan hero back to their ships. As Hector s wife, Andromache, watched from the walls of Troy, she lamented the fate of their orphaned son, Astyanax, and presented a vivid picture of the injustices and humiliations he would endure as a fatherless child (Iliad, 22.484-506). 

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