Poor System Performance

A system becomes non-performant when the speed at which it operates falls below what is specified in the requirements. The impact can be anything from a minor irritant to effective unavailability and can range from an occasional intermittent problem to a persistent characteristic of the system. When the problem is severe users may abandon the system completely and resort to alternative methods of information provision and document keeping. In these cases the impact becomes essentially the same as system unavailability. 

A further discussion on poor system performance is provided in Sect. 7.5. 

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Selection of the most appropriate control device requires consideration of the pollutant being handled and the features of the control device. Often, poor system performance can be attributed to the selection of a control device that is not suited to the -pollutant characteristics. An understanding of the equipment operating principles will enable the design engineer to avoid this problem. 

Systems can often be designed and scaled to meet the requirements of individual organisations. To mitigate the risk of poor system performance healthcare organisations should take appropriate measmes at design time to estimate the numbers of concurrent users. Hosting organisations can use this information to predict the specification and architecture of systan components required to meet performance requirements. 

The combination of carefully projected user numbers, well established application demands and a scalable architecture provides strong evidence to mitigate hazards relating to poor system performance. 

Polyelectrolytes (or polymers) used in water treatment systems have specific storage, handhng, feeding, and dilution requirements. These chemicals are typically fed in low concentration, so it is imperative that these materials be fed accurately to prevent underfeeding and overfeeding, which can result in wasted chemical treatment and poor system performance. 

Discharge configuration importance of designing the system downstream of the mixer such that segregation is minimized (chutes, silos, and pneumatic transfer systems can de-mix the mixture and result in poor system performance)... 

Resias are seldom used oace and discarded. Whether the system is mn batchwise or ia columns, the resia must be periodically removed from service and regenerated. An exception is the use of a resia as a catalyst ia organic reactions. Each cycle consists of two principal steps, adsorption and regeneration, and one or more iatermediate steps, tinse and backwash. Eailure to use good practices results ia poor cycHc performance. 

At times, the process stream flow must be increased after the initial installation to satisfy production demands. Depending on the magnitude of the increase, the existing system may or may not be able to handle the added flow. If it can, regeneration frequency must increase. Adding more resin to the column is often considered an alternative to installing another column. Resin addition lessens the space for backwash and may be a cause for poor column performance. 

Hot spot formation witliin tlie reactor can result in catalyst breakdown or physical deterioration of tlie reactor vessel." If tlie endothermic cyanide reaction has ceased (e.g., because of poor catalyst performance), the reactor is likely to overheat. Iron is a decomposition catalyst for hydrogen cyanide and ammonia under the conditions present in the cyanide reactor, and e. posed iron surfaces in the reactor or reactor feed system can result in uncontrolled decomposition, which could in turn lead to an accidaital release by overheating and overpressure. 

Check the condenser absolute pressure. An increase in the condenser back-pressure, relative to design, is a sign of fouled tubes, air leakage, or poor overall cooling tower system performance. 

Since ice storage tanks are used in HVAC system, the performance should be evaluated from system point of view. If the water distribution system had poor performance, performance of tank would be worse than its design value. Furthermore, heat load characteristics of the building also have large relation to system performance. System performance will be different for the building that has peaky load comparing to the building with flat load. 

By comparing the observed chemical abundance ratios to supernova model yields, one can calculate , the ratio of the number of SNe la to SNe II events that fit the observations and the synthesized mass of the elements from the model yields. In a study adopting the same analysis techniques as those performed here, [5] found large values of for a trio of low-a stars of [Fe/H] -2. Employing the abundances derived in this study of stars with comparable metallicities, I find that the metal-poor systems presented here possess a- and iron-peak abundances (and based on Na, Mg, Si and Fe) consistent with those observed in metal-poor stars of the MWG (e.g., [6]). 

The first methanol-fed PEM EC working with an AEM was conceived by Hunger in 1960 [15,45]. This system contained an AEM with porous catalytic electrodes pressed on both sides and led to relatively poor electrical performance (1 mA cm at 0.25 Vat room temperature with methanol and air as the reactants). Since this first attempt, many studies have been carried out to develop alkaline membranes. 

Example 1 (from Grossmann and Morari, 1983). Traditional industrial practice generates resilient HENs by designing them for what are perceived to be extreme operating conditions. Naturally, if these extremes are selected properly, the HEN will perform satisfactorily for the whole range of expected conditions. This example demonstrates that the proper selection of extremes is far from trivial and that seemingly logical choices can lead to extremely poor systems. 

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