Uncertainties INDEX

Contrac tors bids offer the most rehable information on cost. Order-of-magnitude costs, however, may be required for preliminary studies. One way of estimating them is to obtain cost information from similar facihties and scale it to the proposed installation. Costs of steel storage tanks and vessels have been found to vaiy approximately as the 0.6 to 0.7 power of their weight [see Happel, Chemical Process Economics, Wiley, 1958, p. 267 also Williams, Chem. Eng., 54(12), 124 (1947)]. AU estimates cased on the costs of existing eqiiipment must be corrected for changes in the price index from the date when the equipment was built. Considerable uncertainty is involved in adjusting data more than a few years old. 

To illustrate the usefulness of the Information Index in determining the best time interval, let us consider the grid point (l, 0.20, 35). From Figure 12.7 we deduce that the best time interval is 25 to 75 h. In Table 12.4 the standard deviation of each parameter is shown for 7 different time intervals. From cases 1 to 4 it is seen that that measurements taken before 25 h do not contribute significantly in the reduction of the uncertainty in the parameter estimates. From case 4 to 7 it is seen that it is preferable to obtain data points within [25, 75] rather than after the steady state has been reached and the Information Indices have leveled off. Measurements taken after 75 h provide information only about the steady state behavior of the system. 

Compounds are identified by an IUPAC approved name [93-ano-l], the empirical molecular formula, and the Chemical Abstracts Service Registry Number. A summary table is available for each compound which includes the reported temperature and density values, an assigned uncertainty for the density, the difference between the observed and smoothed density values and an index key to the source of the data. A complete list of references, identified by the index keys, appears at the end of the volume. 

The uncertainty of the calculated spreading factor A(o q) depends upon the accuracy of the inhomogeneity index of the sample and that of the total variance of experimental chromatogram. It may be expressed as... 

WHO/IPCS. 2006. Draft Guidance Document on Characterizing and Communicating Uncertainty in Exposure Assessment. Geneva WHO. http //www.who.int/ipcs/methods/harmonization/areas/exposure assessment/en/index.html... 

Figure 3.1 Analytical working curve for a self-indexed luminescent thermometer based on the ratio between the measured excimer (E, 475 nm) and monomer (M, 375 nm) emission bands of l,3-b/s(l-pyrenyl)propane in [C4Cjpyr][Tf2Nj. The optical thermometer is perfectly reversible in the temperature range shown and highly precise, with the measured uncertainties in the ratio (1 /1 ) falling well within the symbol dimensions. The dashed curve represents the temperature uncertainty predicted from explicit differentiation of a sigmoidal fit to the calibration profile 5T = 0T/0R 5R where R = I /Iu- (Reprinted from Baker, G.A., Baker, S.N., and McCleskey, T.M., Chem. Commun., 2932-2933, 2003. Copyright 2003 Royal Society of Chemistry. With permission.)...

In summary, a variety of LEED patterns have been observed for oxygen adsorption on the platinum metals. However, their interpretation is complicated by the uncertainty in the oxygen coverage. A second complication is the uncertainty introduced by oxygen-induced surface reconstruction. The stability of 22 high index Miller planes upon exposure to oxygen has recently been investigated by Blakely and Somorjai (160). 

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