Visual Basic programming

Excel does not provide functions for the factor analysis of matrices. Further, Excel does not support iterative processes. Consequently, there are no Excel examples in Chapter 5, Model-Free Analyses. There are vast numbers of free add-ins available on the internet, e.g. for the Singular Value Decomposition. Alternatively, it is possible to write Visual Basic programs for the task and link them to Excel. We strongly believe that such algorithms are much better written in Matlab and decided not to include such options in our Excel collection. 

We have developed a new process to improve the efficiency of sample reanalysis. This process includes four steps data review, replating, reanalysis, and data alignment. We have also generated an Excel template, a Gilson s Unipoint protocol, and an in-house visual basic program to automate the process. 

Table 3.3 displays an actual tray design run of the Visual Basic program Tray 10. Prior to clicking on the Run Program button, form 1 data were input along with the default values previously shown. 

Microsoft Corporation, Programmer s Guide for Microsoft Visual Basic, Programming System for Microsoft Windows Version 3.0, Microsoft, Redmond, WA, 1993. 

Using the bubble point pressure option in the Visual Basic program of Appendix B.1-3, the DOS-based program VLMU, or the MATHCAD worksheet PRBUBP, and the computed composition for the liquid richer in n-decane, we obtain the following results for the three-phase coexistence region ... 

The DOS BASIC programs were provided with the third edition, and are also supplied in stand-alone executible and BASIC code forms. They are a similar suite of VISUAL BASIC programs, except that there is no PROPERTY database. The stand-alone versions run in a DOS window, and have less functionality and are not as user-friendly as the VISUAL BASIC programs. Also, the DOS BASIC UNIFAC program uses the original version of UNIFAC (as a result of DOS BASIC memory limitations). The BASIC code programs can be modified if a BASIC or QUICKBASIC compiler is available. 

Visual Basic programs that run in the Windows environment to solve pure fluid and mixture thermodynamics problems and to obtain graphs of the results... 

Most of the software offers in-line programming, either by in FORTRAN, or Visual Basic. Programming is a powerful tool in flowsheeting that allows the user to customise the simulation, or introduce its knowledge. Among applications we may cite the formulation of complex specifications, the transmission of information between different units, to express complex reaction rate expressions, built user simulation units, or prepare data for presentation, interfacing or post-processing. 

Since the use of the simulator requires the solution of different problems, several different problems are formulated in the Problem Solution Visual Basic Module. Their solution is based on the simplest problem of the process model worksheet above, and uses the Solver or the Goal Seek utilities of Excel via a Visual Basic program, to obtain a solution for the alternative problems. 

Since process simulators are used extensively in commercial practice, I have continued to include process simulation examples and homework problems throughout the text. I now teach the required three-credit, junior-level separations course at Purdue as two lectures and a two-hour conputer lab every week. The computer lab includes a lab test to assess the ability of the students to use the simulator. Although 1 use Aspen Plus as the simulator, any process simulator can be used. Chapters 2. 6, 8,10,12, 13. and 16 include appendices that present instructions for operation of Aspen Plus. The appendices to Chapters 2. 4, 5,15, and 17 have Excel spreadsheets, some of which use Visual Basic programs. I chose to use spreadsheets instead of a higher-level mathematical program because spreadsheets are universally available. The appendix to Chapter 18 includes brief instructions for operation of the commercial Aspen Chromatography simulator—more detailed instruction sheets are available from the author wankat purdue.edu. 

Full Mark (100%) General spreadsheet ahle to solve all problems with ability to cope with a range of boundary conditions and load histories as specified in self-explanatory input data. The spreadsheet will make good use of macros and some Visual Basic programming... 

Table Y.2 Matrix for determining intercept (i.e., exit gas) temperature when 20% of Fig. Y.l s exit gas is recycled to the Fig. Y.l feed gas stream, 660 K. The combined (feed + recycle) gas quantities are described in Section Y.2. The combined (feed+recycle) gas composition is described in Section Y.2.1. The intercept (exit gas) temperature is 890 K. This is not the steady-state 20% recycle exit gas temperature. The calculation now has to be repeated with recycle of 20% of the recycle matrix s output quantities substituted until two successive calculations give the same result. A Visual Basic program using... 

Output signals from the shear force sensors and accelerometers were digitized using a DAQ system (Model PCI-3101 board connected to a Model STA-300 screw terminal accessory using a CAB 305 cable, Keithley Instruments, Inc.). The sample rate of the equipment is 4000 samples s which, at a frequency of 208.4 Hz, corresponds to approximately 20 samples cycle. A Microsoft Visual Basic program was used to process and convert the acceleration and force output signals in voltages (V) to units of acceleration (G) and Newtons (N), respectively. 

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