Combinational section Process statement

Unlike the Wait statement, the If does not have to be the first statement in the process. This allows both a synchronous section and combinational logic - a combinational section - to exist in the same process. The example below illustrates this (and assumes that all the signals have been declared in the surrounding architecture). 

This section has illustrated the important part that the Process statement plays in the design of sequential logic. In Chapter 4, its function in combinational design was also shown. It is good design practice to separate combinational and synchronous sections by using different processes. Box 5.1 offers some guidelines on how to use the process statement and illustrates its syntax. 

In general, the fundamental statements given above for the photochemistry in these combinations can be extended to the subject discussed in this section. But, so far, only a little information exists on the influence of monomers on the overall processes. 

In many modelling studies, the model establishment is made in relation to the transfer and balance of a property (for instance see Chapter 3, Section 3.1). Nevertheless, a property evolution from the initial to the final state can vary randomly as a result of the stochastic combination of different elementary processes. This statement is in good agreement with the unitary concept of transfer phenomena [4.9-4.11] and was reported by Bratu [4.11] in the following assertion ... 

Another distinction about discovery bioanalysis is that ease of methods development is often more important than the net speed at which samples can be processed. This statement is again a manifestation of the high number of NCEs that are encountered in discovery. Consequently, enormous growth has occurred with on-line methods that combine sample preparation and analysis in a single injection format. Although several formats exist, the common link to all on-line methods is that they invoke column-switching techniques. The popularity of these methods can be traced, in part, to the ability to adjust extraction/analysis conditions on-the-fly and leads to extremely facile method development. In the section that follows, off-line and on-line methods are considered separately. Coverage of these subtopics can also be found in a number of review articles [4—7,44,45]. 

In performing an actual extraction in the laboratory, you would extract the aqueous phase with a second 1-mL portion of fresh methylene chloride to achieve a more complete extraction. Steps 2-5 would be repeated, and the organic layers from both extractions would be combined. In some cases, you may need to extract a third time with yet another 1-mL portion of methylene chloride. Again, the methylene chloride would be combined with the other extracts. The overall process would use three 1-mL portions of methylene chloride to transfer the product from the water layer into methylene chloride. Sometimes you will see the statement "extract the aqueous phase with three 1-mL portions of methylene chloride" in an experimental procedure. This statement describes in a shorter fashion the process described previously. Finally, the methylene chloride extracts will contain some water and must be dried with a drying agent as indicated in Section 12.9. 

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