Area correction factor

First of all, we used this mathematical model to correlate the in vitro and in situ permeabilities of grepafloxacin and ciprofloxacin [39], and the area correction factor Sf obtained was around 4, in accord with results obtained by other authors [52]. This difference is explained by the differences in absorptive surface in the in situ versus the in vitro model, as the latter presents microvilli but not villi or folds. Now we have expanded the number of element of the correlation to all the quinolones included in Table 4.2, and the area correction factor does not suffer any variation (see Fig. 4.8, p. 104). Even if this model has been constructed using very simplistic assumptions, the results are promising and demonstrate that a good modeling approach helps to identify the system critical parameters and how the system behavior changes from the in vitro to the in situ level [39]. It is important to notice that with this linear correlation we make the assumption that the main difference between both systems is the actual effective area for transport. Nevertheless, since the plot is far from being perfect, it is probable that there are more differences in both experimental systems, such as different paracellular resistance or different expression levels of the transporter, that account for the deviation. 

The chromatograph was calibrated using 11 solvent blends of known compositions. Area correction factors were determined from the standard samples, relating weight fraction to area fraction. All samples were analyzed twice, and the results were averaged. Calibration of the chromatograph with known water-MEK-THF samples indicated accurate determination to within 0.002-0.005 mole fraction, depending on composition. 

The Area Correction Factor (ACF) for the butyltin compounds were determined relative to dodecane by the internal standard technique. The detector response for dodecane was arbitrarily set at unity. 

Compound Relative area Correction factor Corrected area Percentage... 

The Fp correction factor for each enthalpy interval depends both on the assumed value of Xp and the temperatures of the interval on the composite curves. It is possible to modify the simple area target formula to obtain the resulting increased overall area A etwork for a network of 1-2 exchangers ... 

Inclined belts provide additional areas of contact with the pulley magnetic field and can tolerate higher capacities than normal for a magnetic pulley apphcation. Table 3, which iadicates the correction factor to be appHed to the capacity, can be used with Table 2 to make the magnetic pulley diameter selection for an inclined belt. The initial cost of units can be related to the capacity or volume throughput. Costs mn about 35 for each m /h on the smaller units about 50 for each m /h on larger units. 

The correction factor can be quite low requiring an uneconomically large area. 

The settling velocity of a nonspherical particle is less than that of a spherical one. A good approximation can be made by multiplying the settling velocity, u, of spherical particles by a correction factor, iji, called the sphericity factor. The sphericity, or shape factor is defined as the area of a sphere divided by the area of the nonspherical particle having the same volume ... 

Calculations of Orifice Flow Area using Pressure Relieving Balanced Bellows Valves, with Variable or Constant Back Pressure. Must be used when backpressure variation exceeds 10% of the set pressure of the valve. Flow may be critical or non-critical for balanced valves. All orifice areas. A, in sq in. [68]. The sizing procedure is the same as for conventional valves listed above (Equations 7-10 ff), but uses equations given below incorporating the correction factors K, and K,, . With variable backpressure, use maximum value for P9 [33a, 68]. 

Since the viscosity correction factor is dependent upon the actual orifice area, direct solution is not possible and a trial orifice size must be found before Ihe Ku can be determined accurately. 

Select Ihe next larger orifice size, or an M" orifice with 360 sq in. orifice area. (This should be about 20% greater than the calculated area to allow lor reduction of capacity due to Ihe viscosity correction factor "Ku")... 

Capacity factor based on tower area, ft/sec Capacity fector at flood, ft/sec Liquid gradient vapor load correction factor or Discharge coefficient (see accompanying table) or Gas phase loading factor, ft/sec. Equation 8-281 Eddy loss coefficient, dimensionless. Table 8-22 Wet cap pressure drop correction factor. Figure 8-115... 

F = MTD correction factor, dimensionless FA = face area, fF FV = standard air face velocity, sfm G = mass velocity, lb/ (sec) (fF) h = individual heat transfer coefficient,... 

The denominator in this equation represents the area under the curve of Figure 5.12 and serves to normalise the expression, so that f(x) —> 1 as x 0- The absorption correction factor Ea is equal to 1 //(%). 

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