Calculations using spreadsheets

The net present value is always less than the total future worth of the project because of the discounting of future cash flows. Net present value is easily calculated using spreadsheets, and most spreadsheet programs have an NPV function. 

The second section of the spreadsheet contains the overall flows, the calculated component flows, and the material balance closure of each. The weighted nonclosure can be calculated using the random error calculated above, and a constraint test can be done with each component constraint if desired. Whether the measurement test is done or not, the nonclosure of the material balance for each component gives an indication of the validity of the overall flows and the compositions. If particiilar components are found to have significant constraint error, discussions with laboratory personnel about sampling and analysis and with instrument personnel about flow-measurement errors can take place before any extensive computations begin. 

A non-linear regression analysis is employed using die Solver in Microsoft Excel spreadsheet to determine die values of and in die following examples. Example 1-5 (Chapter 1) involves the enzymatic reaction in the conversion of urea to ammonia and carbon dioxide and Example 11-1 deals with the interconversion of D-glyceraldehyde 3-Phosphate and dihydroxyacetone phosphate. The Solver (EXAMPLEll-l.xls and EXAMPLEll-3.xls) uses the Michaehs-Menten (MM) formula to compute v i- The residual sums of squares between Vg(,j, and v j is then calculated. Using guessed values of and the Solver uses a search optimization technique to determine MM parameters. The values of and in Example 11-1 are ... 

Energy balance calculations are best solved using spreadsheets or by writing a short computer program. A suitable program is listed in Table 3.2 and its use described below. The use of a spreadsheet is illustrated in Example 3.14b. 

Fig. 15 Spreadsheet illustrating the calculation of plasma concentrations after multiple extravascular doses, calculated using Eq. (56).

Although this equation cannot be solved analytically for A pi, it can be solved by iteration (or by using the solve command on a calculator or spreadsheet), because all other parameters are known. The unknown velocity is then given by... 

Table 19.1 shows the calculations, in spreadsheet form, for E(t) (from summation form of equation 19.3-4, with C(t) = Eft), and using equation 19.3-15), f (equation 19.3-7a), and of (equation 19.3-8a). (Subscript i has been omitted from the headings for brevity.)... 

Once the mass spectmm of a calibration standard is known and the elemental composition of the ions that are to be included in the mass reference list are established by an independent measurement, a reference list may be compiled. For this purpose, the listed reference masses should be calculated using six decimal places. Otherwise, there is a risk of erroneous reference values, especially when masses of ion series are calculated by multiplication of a subunit. Such a tasks are well suited for spreadsheet applications on a personal computer. 

Finally, one can use spreadsheets (e.g. Excel, Lotus) to calculate the effects of the factors and to interpret the results. An example with Lotus-1-2-3 is given in reference [44]. 

For the calculation this spreadsheet will use information from other spreadsheets ... 

Methods which are suitable for evaluation using a pocket calculator or spreadsheet... 

Anyone with a serious need to calculate redox titration curves should use a spreadsheet with a more general set of equations than we use in this section.5 The supplement at www.freeman.com/qca explains how to use spreadsheets to compute redox titration curves. 

Manufacturers of prepolymers will often provide the weight of curative per 100 units of prepolymer. This is based on the midpoint NCO for the grade and the normal index value for the curative. The calculations can readily be carried out using a calculator or spreadsheet. From a practical point of view, a set of shop scales with a discount function has been used to provide the weight required. 

In practice, data normalization is calculated using a spreadsheet or other of computer program. The best programs are integrated into a package that includes the hardware to actually capture the raw data. This eliminates the need to manually enter data. In general, systems that require manual data entry do not stand up to the test of time operators will usually cease manually entering data within the first couple of months after start-up, and they are left with only observed data with which to analyze performance. As discussed previously, observed data are unreliable due to the effects of pressure, temperature, and concentration on product flow and salt rejection. 

Use of the CDS to earry out all calculations rather than using a calculator or spreadsheet. This streamlines the whole process for ealeulating, reviewing, and approving results. 

First perform the integration analytically, using a table of integrals if necessary then write a spreadsheet or computer program to do it using Simpson s rule (Appendix A.3). Have the program evaluate Cp at 11 equally spaced points from 150 C to ISOO C, estimate and print the value of A//, and repeal the calculation using 101 points. What can you conclude about the accuracy of the numerical calculation ... 

Construct a spreadsheet program to perform these calculations, using the goalseek tool to carry out the trial-and-error search for the correct value of fiv6- Fill in the table of pan (b). 

For the final activity calculations a software package called LSC Plus (supplied by Raddec Ltd.) is used. This software was developed to avoid using spreadsheet calculations, to minimize transcription errors and to save time. The counting of samples on Quantulus consists of 3 repeat counts. For example, when counting a batch of 20 samples, it produces 60 individual results you then have to manually enter into a spreadsheet. It automatically imports those data and calculates final results and total expanded uncertainties together with the LODs (Fig. 5). It has built-in quality control features introduced to assist in the requirements of ISO17025. 

Most cost-estimating and economic analysis calculations are easily carried out using spreadsheets. Templates are introduced in the examples throughout the chapter. Blank templates are given in Appendix G and in the online material at http //books. elsevier.com/companions. The more sophisticated software that is used in industry for preliminary estimating is discussed in Section 6.3. 

Many of the calculations described in the book can be performed using spreadsheets. Templates of spreadsheet calculations and equipment specification sheets are available in Microsoft Excel format online and can be downloaded by all readers of this book from http //books.elsevier.com/companions. 

Copy the value of a variable or a formula in one cell into other cells Execute an iterative calculation using the spreadsheet function... 

Use method (iv) to find p and Y. Make an initial estimate of say, using a psychrometric chart. Calculate Yas from Eq. (12-6). Find p from Table 12-1 and from Antoine equation (12-5). Repeat until iteration converges (e.g., using spreadsheet). 

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