Calculation of weight average

Computer programs (106, 107) have been developed to facilitate the calculation of weighted average equilibrium constants and their standard error from the experimental data and the error estimation between the... 

There arc many formulas for the calculation of weighted averages. For example, the number-surface mean diameter calculates the mean diameter based upon the surface area and number of particles ... 

Figure 20. Example Calculation of Weight Average Reactor Temperature (WABT)...

AS-SOLID TRANSPORT Calculation of weight average diameter from sieve analyses ... 

Using this concept, Burdett developed a method in 1955 to obtain the concentrations in mono-, di- and polynuclear aromatics in gas oils from the absorbances measured at 197, 220 and 260 nm, with the condition that sulfur content be less than 1%. Knowledge of the average molecular weight enables the calculation of weight per cent from mole per cent. As with all methods based on statistical sampling from a population, this method is applicable only in the region used in the study extrapolation is not advised and usually leads to erroneous results. 

In the calculation of ensemble averages, we correct for the weighting as follows... 

When a mixture is cracked, one or more components in the feed may also be formed as products. Eor example, in the cocracking of ethane and propane, ethane is formed as a product of propane cracking and propane is formed as a product of ethane cracking. Therefore, the "out" term in the above equation contains the contribution or formation from other feed components and hence does not represent tme conversion. Eor simple mixtures, the product formation can be accounted for, and approximate tme conversions can be calculated (29). Eor Hquid feeds like naphtha, it is impractical if not impossible to calculate the tme conversion. Based on measured feed components, one can calculate a weighted average conversion (A) (30) ... 

Choose the most appropriate runoff coefficient for your site or calculate a weighted-average coefficient, which takes into account different types of land use at your facility ... 

The gas pseudo critical pressures and temperatures can be approximated from Figure 2-16 or they can be calculated as weighted averages of the critical temperatures and pressures of the various components on a... 

There are various methods for the determination of the surface area of solids based on the adsorption of a mono-, or polymolecular layer on the surface of the solid. These methods do not measure the particle diameter or projected area as such, but measure the available surface per gram or milliliter of powder. The surface measured is usually greater than that determined by permeability methods as the latter are effectively concerned with the fluid taking the path of least resistance thru the bed, whereas the adsorbate will penetrate thru the whole of the bed as well as pores in the powder particles. These methods appear to be more accurate than surface areas calculated from weight averages or number averages of particle size because cracks, pores, and capillaries of the particles are included and are independent of particle shape and size... 

Data points are calculated as weighted average values solid line is the cross-section function best fitted to the experimental data broken line represents the results of Maier (10). Ion energies are given in lab. scale in e.v. 

The pre-gel model calculates the weight average molecular weight of the reaction mixture, while the post-gel model calculates the weight of the sol fraction and the effective crosslink density. A simple computer program using the derived expressions has been written in BASIC and runs on IBM-PC compatible computers. The importance of secondary reactions on cure in typical coatings is discussed. 

It should be noted that in order to calculate the weight average number of LCB point per 1000 repeat units, one must divide By by My. The use of here is incorrect. 

Table II. Calculation of Weight- and Number-Average Degrees of Polymerization from Fractionation Data0 ...

The monthly isotopic composition (8lsO) of lake evaporate from Sparkling Lake was estimated by use of eq 12. Monthly evaporation rate estimates were then used to calculate the weighted average annual 8lsO of lake evaporate, — 16.9%,. 

The next problem which needs to be discussed in modelling a process is the calculation of an average molecular weight, because the performance characteristics of a material depend on its molecular weight. It is well known that the average molecular weight of a polymerized product depends on the degree of conversion (3, and if the chemical evolution of the reaction is known, the molecular parameters of the reactive system can be found. 

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