Efficiency indicators

Particulate filtration removes suspended liquid or solid materials whose size, shape, and mass allow them to remain airborne at the air velocity conditions present. Filters are available in a range of efficiencies, with higher efficiency indicating removal of a greater proportion of particles and of smaller particles. Moving to medium efficiency pleated filters is advisable to improve lAQ and increase protection for equipment. However, the higher the efficiency of the filter, the more it will increase the pressure drop within the air distribution system and reduce total airflow (unless other adjustments are made to compensate). It is important to select an appropriate filter for the specific application and to make sure that the HVAC system will continue to perform as designed. Filters are rated by different standards which measure different aspects of performance. 

A review of ventilation efficiency indices is given below. Complete mixing ventilation is the comparative basis for all efficiencies, with the value 1.0. That may be useful, as complete mixing ventilation often is assumed in early design phases. 

Air exchange efficiency indices can be used for cases where no or little information on sources is available, whereas ventilation efficiency, which concerns workers, can be used where very detailed information is available on sources and activities. 

In order to have effective exchange of air in important locations in a room, the age of the air in those locations should be low. The basis for comparison is the complete mixing scenario. That scenario gives the same age for any air volume selected in the room, identical to the nominal time constant for the ventilation airflow,. A steady-state scenario is assumed. See Sutcliffe for an overview of definitions related to age of air. The various air exchange efficiency indices are presented in Table 8.6. 

Ventilation efficiency Indices that provide a method of assessing the mixing characteristics of incoming air with the room air. It presents a means of determining the pollutant distribution within the space. 

Inhibitor Efficiency. The value of corrosion inhibitors can be compared on the basis of inhibitor efficiency. Inhibitor efficiency indicates the percentage that corrosion is lowered in the presence of the inhibitor as compared to that in its absence. Inhibitor efficiency can be calculated by using the formula... 

As indicated in Fig. 1, nitrogenase can reduce substrates other than Na. In the absence of other reducible substrates it will reduce protons to dihydrogen, but it can also reduce a number of other small triple-bonded substrates, as indicated in Section V,E,1. Large substrates are not reduced efficiently, indicating physical limitations on access to the enzyme s active site. CO is a potent inhibitor of all nitrogenase substrate reductions except that of the proton to Ha. In the presence of CO the rate of electron transfer is generally not inhibited, but all electrons go toward the production of Ha. 

Abad-Zapatero, C., Metz, J. T. Ligand efficiency indices as guideposts for drug discovery. Drug Discov. Today 2005, 10, 464 69. 

Goins, G. D., Yorio, N. C., Wheeler, R. M. (2004). Influence of nitrogen nutrition management on biomass partitioning and nitrogen use efficiency indices in hydroponically grown potato. J. Amer. Soc. Hort. Sci., 129, 134-140. 

Abad-Zapatero, C. Ligand efficiency indices for effective drug discovery. Expert Opin. Drug Discov. 2007,2, 469 188. 

Efficiency indicators. This type of indicator reflects the level of efficiency of an anthropogenic impact on the environment that can be seen by changes in biogeochemical cycles. 

The rational design of a reaction system to produce a desired polymer is more feasible today by virtue of mathematical tools which permit one to predict product distribution as affected by reactor type and conditions. New analytical tools such as gel permeation chromatography are beginning to be used to check technical predictions and to aid in defining molecular parameters as they affect product properties. The vast majority of work concerns bulk or solution polymerization in isothermal batch or continuous stirred tank reactors. There is a clear need to develop techniques to permit fuller application of reaction engineering to realistic nonisothermal systems, emulsion systems, and systems at high conversion found industrially. A mathematical framework is also needed which will start with carefully planned experimental data and efficiently indicate a polymerization mechanism and statistical estimates of kinetic constants rather than vice-versa. 

Greater application of polymerization reaction engineering within the commercial context requires further theoretical development in high conversion systems of interest. A mathematical framework is needed which will start with carefully planned experimental data and efficiently indicate a polymerization mechanism and statistical estimates of kinetic constants, rather than vice-versa. Better cross-communication between... 

Another so-called efficiency, known as hydraulic efficiency, is sometimes given for reciprocating pumps. This efficiency indicates losses due to velocity changes in the inlet and outlet of the pump, friction, and valves. It is defined as the ratio of the actual head across the pump to the sum of the actual head pumped and the losses in the suction and discharge lines. 

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