Spreadsheets

From the probability distributions for each of the variables on the right hand side, the values of K, p, o can be calculated. Assuming that the variables are independent, they can now be combined using the above rules to calculate K, p, o for ultimate recovery. Assuming the distribution for UR is Log-Normal, the value of UR for any confidence level can be calculated. This whole process can be performed on paper, or quickly written on a spreadsheet. The results are often within 10% of those generated by Monte Carlo simulation. 

Discounting can also be performed, of course, using a programmable calculator or a spreadsheet such as Lotus 1-2-3 or Microsoft Excel. 

The text form for parameters uses white space or commas to separate the fields (columns) of the parameter tiles. They can be read by ordinary text editors, w ord processors, etc. In the text form, param eters are easy to m odify but not easy to com pare, stn dy, etc. Many database program s are capable of reading column s of text as a database, h owever. Wh ile spreadsheets are n ot. per se, databases, they can be useful for examining parameter sets. Microsoft Excel, for example, can read the text form of a param eter file and pn t the data in a form easily manipulated as a matrix or a database. The text form of parameters are stored, by default only, in Tart files. 

The dBASEIV (ordBASEIIT) form of th e parameter sets come in ld( /filcs analogous to the Tt,v( files. Th ese dbf files are bin ary files, so yon can t read them directly. They arenot retpiired for the product and are provided only as an option. In most situations where there is no exten sive use of database operation s on parameter sets, the text form is probably more convenient to use. Many spreadsheet programs, including Microsoft Excel, are also capable of reading files. 

Once entered into a spreadsheet, data can be manipulated column at a time. For example, let us take the top cells in Table 1-3 as cells A3 and B3 (columns A and B, line 3 in Table 1-3) containing 5 and 0.305 to avoid dividing 0 by 0. Using the easycalc option of the tools menu in Excel, divide the contents of B3 by A3 and place the results in cell C3. Now select C3 and the remaining 12 unfilled cells in the column, C3 to Cl 5, and fill down using the mouse. The results of the calculation of Cp/T appear for all remaining cells in the C column. 

Note that different spreadsheets and different versions of the same spreadsheet vary in the details of the calculation but that the basic idea for all is to cany out the calculation for the top cell and fill in the remaining cells in the same column with the mouse—a very convenient technique for simple calculations on large data sets. Consult the Help section of your spreadsheet for specific details. 

On entering SigmaPlot (we use version 5.0), one is presented with a data table that is essentially a spreadsheet. Enter T as the independent or A -variable into the first eolumn of the SigmaPlot data table and Cp/T as the dependent or y-variable into the second column. The SigmaPlot data table should resemble columns 1 and 3 of Table 1-3. Rounding to three significant figures is permissible. 

A typical plot of x vs./(x) is considered to have one coordinate dimension, the X, and one data dimension,/(x). These data sets are plotted as line graphs, bar graphs, and so forth. These types of plots are readily made with most spreadsheet programs as well as dedicated graphing programs. Figure 13.1 shows two graphs that are considered to have a one-dimensional data space. 

Output data can be printed or exported to a spreadsheet. The rendering quality is very good. Structures can be rendered and labeled in several different ways. Molecular structures can be saved in several different formats or as image files. The presentation mode allows molecular structures to be combined with text. 

The property calculation experiment offers a list of 34 molecular properties, including thermodynamic, electrostatic, graph theory, geometric properties, and Lipinski properties. These properties are useful for traditional QSAR activity prediction. Some are computed with MOPAC others are displayed in the browser without units. A table of computed properties can be exported to a Microsoft Excel spreadsheet. 

Donato, H. Metz, G. A Direct Method for the Propagation of Error Using a Personal Gomputer Spreadsheet Program, ... 

Although equations 5.13 and 5.14 appear formidable, it is only necessary to evaluate four summation terms. In addition, many calculators, spreadsheets, and other computer software packages are capable of performing a linear regression analysis based on this model. To save time and to avoid tedious calculations, learn how to use one of these tools. For illustrative purposes, the necessary calculations are shown in detail in the following example. 

Machuca-Herrera, J. G. Nonlinear Gurve Litting with Spreadsheets, /. Chem. Educ. 1997, 74, 448-449. 

This is a more difficult equation to solve than that for the solubility of Pb(I03)2 in distilled water, and its solution is not immediately obvious. A rigorous solution to equation 6.34 can be found using available computer software packages and spreadsheets. 

The approach that we have worked out for the titration of a monoprotic weak acid with a strong base can be extended to reactions involving multiprotic acids or bases and mixtures of acids or bases. As the complexity of the titration increases, however, the necessary calculations become more time-consuming. Not surprisingly, a variety of algebraic and computer spreadsheet approaches have been described to aid in constructing titration curves. 

A number of statistics and spreadsheet software packages are available to perform ANOVA calculations. 

Many of the topics covered in analytical chemistry benefit from the availability of appropriate computer software. In preparing this text, however, I made a conscious decision to avoid a presentation tied to a single computer platform or software package. Students and faculty are increasingly experienced in the use of computers, spreadsheets, and data analysis software their use is, I think, best left to the personal choice of each student and instructor. 

Spray-up process Spreading Spreading agents Spreadsheet programs Sprengel mixture SprintNet... 

The ubiquitousness of the personal computer and the increasing power of the program packages available for it have shifted the emphasis away from large, mainframe-based systems like PLATO. Instead, graphics are included in utihty programs such as equation solvers, spreadsheet processors, and word processors. 

Spreadsheet programs were originally developed for bookkeeping and business-planning appHcations over time, many additional features were added. Visica/c, which appeared in the early 1980s, was the first spreadsheet program it was developed for Apple computers. 

A spreadsheet program is intuitive in its operation and can immediately show the effect of any one change throughout the whole spreadsheet. It is thus a subtie form of data vaHdation an error may be spotted immediately. Furthermore, when a material balance is set up, the total effect caused by a change in one variable may be seen at once. 

Another implicit advantage to use of spreadsheets, besides thek ubiquity and ease of use, is the fact that so many engineers and scientists already are familiar with them. Thek use then obviates the need to learn another programming language. 

Spreadsheet Applications. The types of appHcations handled with spreadsheets are a microcosm of the types of problems and situations handled with fuU-blown appHcation programs that are mn on microcomputers, minis, and mainframes and include engineering computations, process simulation, equipment design and rating, process optimization, reactor kinetics—design, cost estimation, feedback control, data analysis, and unsteady-state simulation (eg, batch distillation optimization). 

In using a spreadsheet for process modeling, the engineer usually finds it preferable to use constant physical properties, to express reactor performance as a constant "conversion per pass," and to use constant relative volatiHties for distillation calculations such simplifications do not affect observed trends in parametric studies and permit the user quickly to obtain useful insights into the process being modeled (74,75). 

Current spreadsheet programs contain many advanced capabiUties and enhancements that an engineer might want to use they also offer improved performance, interfaces to data base and word-processing programs and have a host of other features. A good overview that describes the features and presents what is available in each of the latest spreadsheet packages on the market is available (78). 

Whereas the general office community reaped the benefits (and endured the pain) of the rise of the personal computer, the scientific and technical market was forced to wait. Chemists used spreadsheets and suffered through word processors that did not know what a chemical stmcture was. However, there is now a good variety of personal productivity tools that have been designed specifically for the chemist. 

Finite Difference Methods Solved with Spreadsheets A... 

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