MathCAD file

The schematic in Fig. 3.44 of the Chebyshev band pass filter utilized the predicted values from the MathCAD file, where lab resources allowed. Close approximations were used, to which the circuit performance was extremely sensitive. Any deviations from the values predicted in the MathCAD file resulted in gain in the pass band. Using SPICE to test possible circuit realizations greatly reduces the time to implement hardware. SPICE will predict if a given circuit realization will perform as desired with available parts, before actual hardware measurements are made. This is helpful because Chebyshev circuit realization can be difficult small changes in the circuit elements can result in undesired performance. The simulated AC results from IsSpice, PSpice, and Micro-Cap are shown in Figs. 3.45, 3.46, and 3.47, respectively. The measured breadboard AC response of the filter is shown... 

The Chebyshev low pass filter shown in Fig. 3.53 was constructed in all three simulators as well as in hardware. The circuit values in Fig. 3.53 were used in all cases. A MathCAD file that was used to design the Chebyshev low pass filter is located in the Chebyshev directory of the CD, which accompanies this book. This file can easily be modified to accommodate designs that use a Sallen-Key circuit for each stage of the filter (see Fig. 3.54). The schematic of the circuit that was used in each simulator is shown in Fig. 3.53. The measured breadboard results are shown in Fig. 3.55, and the simulated results are shown in Figs. 3.56, 3.57, and 3.58. 

To cap it all, there is an interview-friendly FAQ, several Mathcad files, and various design spreadsheets thrown in. 

This can only be solved by numerical integration. (See MATHCAD file for this problem). 

MathCAD File Name McCabe2001-liquid-feed.MCD... 

All the topics are illustrated with examples that are closely related to practical process simulation problems. At the end of each chapter, additional calculation examples are given to enable the reader to extend his comprehension. An introduction to a larger number of problems can be found in Qiapter 15. These problems and their solutions can be downloaded from the site www.ddbst.com. The problems partially require the use of the software Mathcad and the Dortmund Data Bank Software Package - Explorer Version. Both packages can be downloaded from the Internet. The DDBSP Explorer Version is free to use, whereas Mathcad is only available for free during a tryout period of 30 days. Mathcad files enable the users to perform the iterative calculations themselves and get a feeling for their complexity. Often, typical pitfalls in process simulation are covered in the examples, which should be helpful for the reader to avoid them in advance. 

Since a separation at infinite dilution is not of practical interest, additionally the separation factors for a sulfolane mole fraction of 0.8 should be calculated using modified UNI FAC. The Mathcad-File can be used to predict the activity coefficients of benzene and the n-alkanes in a mixture of 80mol% sulfolane, 10 mol% benzene, and 10 mol% n-alkane. The predicted activity coefficients using modified UNIFAC and the separation factors are given in the table below. Now lower activity coefficients are predicted, and the activity coefficient of benzene also depends on the M-alkane considered. From the activity coefficients and the vapor pressures again, the separation factors can be calculated. The ratios of the activity coefficients and the ratio of the vapor pressures are shown together with the separation factor au in Figure 11.22. 

Using the Mathcad-File 12.02, the following residual enthalpies are obtained at 600 atm ... 

Using modified UNIFAC, an i-butene conversion of 0.9211 is obtained, which results in the following equilibrium composition, activity coefficients and Ky (see Mathcad file 12.05). 

Of course the result is identical with the result of the relaxation method discussed in Example 12.6. For other temperatures, the equilibrium composition is shown in Figure 12.12 for a pressure of 40 atm. The iterative solution is shown in the Mathcad file 12.08. 

MAS remains the traditional optirai of downloading the worksheets from servers to improve or extend them (which should referenced appropriately). Thus, the site of this book contains references, pictures (pic), Mathcad files (mcd), and MAS documents, as was noted in the preface... 

Converting a worksheet for Web distribution, we should examine this commenting rule. The point is that a bulky document decelerates the Web and loads a server with superfluous operations. For this reason, it is worthwhile to place the main comments, the creation history, the detailed description, instmctions etc, into a separate non-Mathcad file, for example, html-file created in Word or FrontPage. The Mathcad worksheet itself should contain short comments and references to the bulky , additional comments that the user may open in a new browser window. For the same reason, the user should avoid inserting too many complex plots. It is better to freeze static plots that do not change with the source data varying and insert them as pictures. 

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