Best-case operating conditions

The minimum delay requirements are set by the hold constraints for the sequential cells. Hold time problems are caused due to short delay paths between registers which cause the data signal to propagate through two adjacent flip-flops on a single clock edge. Since path delays are the shortest under best-case operating conditions, hold time problems are maximum in these conditions. Hence, hold violations have to be fixed under these conditions. 

Giddings made a stalwart effort to provide values for the different constants that would apply to diverse stationary phase and support conditions [2]. However, at best, his values are the closest estimates from an assumed set of conditions that may fit, to a greater or lesser extent, the properties of the actual stationary phase or support in use. In some cases, his constants may be used in column design and to help in the choice of those operating conditions that will provide the required... 

Within realistic conditions of operation, the shortest lifetime (1200 y) represents the worst case, which is certainly difficult to envision for this situation, HT granules would have the smallest possible size (1 mm) and would dissolve at the fastest rate (10-3 g/m2 x day). Likewise, the longest lifetime (6 x 105 y) is the best case scenario, which might never happen HT granules would have the greatest size and dissolve at the lowest corrosion rate. These two extreme lifetimes are thus not considered to be plausible. For the most realistic estimates, one would expect the hypothetical HT material to last for ca. 104-105 years, which is remarkably favourable. 

Star anise volatile oils can also be isolated by supercritical C02 extraction coupled to a fractional separation technique. Gas chromatography-mass spectrometry analysis of the various fractions obtained in different extraction and fractionation conditions allowed the identification of the best operating conditions for the isolation of essential oil. A good extraction performance was obtained operating at 90 bar and 50°C (for 630min) for both treated materials. Optimum fractionation was achieved in both cases by operating at 90 bar and -10°C in the first separator and at 15 bar and 10°C in the second (Della Porta eta/., 1998). 

The establishing of the optimal process structure and the best operating conditions characterizes the process development at this stage. Firstly, attention must be focused on the synthesis of the proceess. The extent to which models can be used in this phase varies. If we have a new process, information from similar cases may not be available at this stage. In the opposite situation, when the chemical components are well known, which usually means that their properties and... 

Pursuit of strategies. The brief outlines above may serve to characterize the possible options in process development. They describe clear-cut, "pure" strategies, but, of course, modifications are possible. For efficient development it is important to decide as early as possible on the merits of the case which tack to take. If the chosen approach is evolutionary or empirical, expected best operating conditions for the eventual plant should dominate the design of the experimental program. In contrast, if the fundamental approach is taken, the clear aim should be to establish networks and mechanisms beyond reasonable doubt with the fewest possible experiments, even if their conditions are far remote from those likely to be employed in the plant. Only when networks and mechanisms are believed to be in hand, should predictions for expected plant conditions be made and verified. An attempt to look at plant conditions while pursuing the fundamental approach is apt to syphon off valuable manpower and time from the principal effort ... 

In the case of pharmaceutical wastewater, it shows when its oxygen concentration was 60%, the amount of total dissolved oxygen is the most. According to the condition and concentration of wastewater and the recovery of 02-PSA used in other wastewater treatment plants, the optimal, and most economical oxygen concentration and operating conditions will be decided. This study shows that oxygen with 90% concentration or higher doesn t have the best treatment efficiency and economical value. 

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