The interpolation routine is here.

]]>The labview 2018 vi can be downloaded here.

]]>It is a very simple routine, the attached vi (in Labview 2018) can be downloaded here. It is used in calculating the Seebeck coefficient in other routine that will be posted here.

]]>The documentation and references are listed in the routine. For instance, for Chromel leg

Chromel (june 2013) , valid from 300K to 873K

Ahmad et al, j phys 1974

Coefficient values ± one standard deviation

K0 = 0.47481 ± 0.0426

K1 = 0.14805 ± 0.000973

K2 = -0.0003499 ± 6.83e-06

K3 = 3.5873e-07 ± 1.97e-08

K4 = -2.1636e-10 ± 2.48e-11

K5 = 7.13e-14 ± 1.13e-14Polynomial fit, temp in K, output in microVolts per Kelvin (within +/- 0.5 microV)

When measuring Seebeck coeficients one needs the absolute values of the leg, if the potential difference is measured through a thermocouple leg. Be aware that some producers of thermocouples do not use standard legs, they are only concerned witht the difference between legs.

The file an be downloaded here.

]]>However, the program can be used without pesgo32.ocx if only the conversion data file is used. The installation file is powderCab. Unit cell refinement is also possible without the graphic part.

]]>

An installation program for Win 95 or NT is provided. If installed on recent OS will need to register some OCX.

To download the file : VERSAT.

In the following the original Help file is pasted :

—

# $ K Versatile 1.00 – Help

The purpose of the program

The author

Available screens:

-About

-Data Editor

-Import

-Graphics

-Main display

-Simulation

Copyright notice

In some areas, a context sensitive Help is available. Do not hesitate to press the F1 key when you are in doubt.

For more information using help, see the Help on Help menu in the Data Editor, or press the Search button from the Help window.

# $ K About

This form (in this document, by form a window or a panel is named) shows the program author and address and a short disclaimer notice. For suggestions and availability please write to the author. I would be grateful to receive any information about the bugs you may find (any other suggestions are welcome). In such case, please submit all the necessary information in order to correct them.

However, do not expect to receive answers to all questions you have. This help file is desigated to this purpose (some knowledge about the Windows environment are highly reccomended).

# $ k The Data Editor

This form is destinated to help you editing the data file. You may want to edit the data file by an appropriate text editor but is neither faster nor safer (the appropriate format will not be described here, however it is easy to find it).

In this form, you will see:

-A menu

-A tabbed dialog

-A data grid

-An estimated error text field

-An experiment name text field

# $ K The Data Editor – The menu

The menus available in this form are:

-File

-OK

-Save

-Open

-Import ASCII file

-Print

-Export ASCII file

-Edit

-Import picture

-Cancel edit

-Smooth Y values

-Shift X values

-Discard data

-Swap data

-Help

A context sensitive Help file, press F1 for the appropriate help message or read carefully the help file.

# $ K The Data Editor menu – File

-OK

This means that you finished editing your data and you want to return to the main window of the program. When you click this menu a check of the data is performed. There are several restrictions (related to the data type) in the data editing procedure in order to assure a normal program flow. These restrictions are compulsory, in the unfortunate case of an error the appropriate message will occur.

If you still want to quit the data editor window, neglecting these restrictions, you will not be allowed to compute your data.

-Save

A data file can be saved by using this command. This data file is checked for consistency before saving. The filename extension proposed is .dat but you can change it. Attention, if you change the filename extension make sure that you select the Show all (*.*) in the Type field. If not, you may obtain a finame like your_filename.your_extension.dat which is a valid filename in Windows 95 (you may have problems in finding it later under DOS).

If it is all right, you can retrieve your file at a later time. It is always reccomended to save the data file for a future use. This data file can be saved also from the main part of the program.

-Open

You can open a data file. Attention, only a consistent data file will be readed. It is advisable to open a file which was created by this program.

-Import ASCII file

With this command you can import a two columns data file into the grid. The first line is taken as an experiment description. This is a very useful command when you have a lot of data (obtained from some simulations, for instance) and don’t want to insert all those data by yourself. Attention: the inserted data does not erase the data you already have inserted but just added at the end of your existing data. If you want to, you may clear all the data at any time.

For the CRTA data: do not let an empty line in the ASCII data file. An empty line should be inserted in the data grid by a CTRL+INS command (this empty line is used in the CRTA mode, to separate the data for the two decomposition rates).

-Print

This is a simple printing routine (if you want to have a hardcopy of the data file). The result depend on your printer.

-Export ASCII file

This is the reverse command of the Import ASCII, described earlier. A two colums ASCII file is created (with the name and location you want), it comprises all the data from the grid.

# $ K The Data Editor menu – Edit

The available commands are:

-Import picture

Use a bitmap file for reading the data points. For further information see the Import form help comments.

-Cancel edit

Stops the editing and returns to the main form of the program. When you use this command the check of the data file will not be performed. However, the data are kept in memory.

-Smooth Y data

This procedure will smooth the Y data you have in the grid. The smoothing is based on a two degrees polynomial over five adjiacent point. The smooth may affect the quality of your data. Use it with care.

-Shift X data

By this command you can shift all the values of temperature by a certain value. This may be useful if you want to analyse the effect of the temperature gradients to the results.

-Discard data

Discard and loss all data from the grid. This operation is reccomended when you already have some data inserted and want to input other data from an ASCII file (by the Input ASCII command the data are merged).

-Swap data

Swap the X and Y data in the grid.

# K $ The tab dialog

It is quite common under Windows 95 or MS Office environment; it is used to select the methods for nonisothermal kinetics data analysis. There are four different cases:

Integral

Differential

Regression

CRTA

# $ K Integral methods

Performs non-isothermal kinetic parameters evaluation under the ‘integral’ approximations, that is the integration of the “temperature integral”. The necessary data may be inserted as temperature vs TG, conversion, DTG or DTA. If necessary a numerical integration is performed (it can be used but it is not reccommended). These methods are very popular and will not be discussed here. For additional information check the papers reffered here. Four calculation methods are available (others will be probably added at a later time):

-Coats-Redfern, according to the paper A. W. Coats and J. P. Redfern; Nature, 201(1964)67; they proposed a very simple (and still effective) approximation by truncating to the first two terms of the assymptotic approximation.

-Flynn-Wall method (J. H. Flynn and L. A. Wall; Polym. Lett. 4(1966)323), is based to the Doyle approximation (C. D. Doyle; J. Appl. Polym. Sci.; 6(1962)639)

-van Krevelen et al (D. W. van Krevelen, C. van Heerden and F. J. Huntjens; Fuel, 30(1951)253 ), used an approximation which is quite ineffective (unless the working temperature is high).

-Urbanovici and Segal (E. Urbanovici and E. Segal; Thermochim. Acta 80(1984)379). The computed parameters are generally lower than the other methods (up to 5 %) but describe very well the experimental data.

When the Integral methods are selected you have to insert in the appropriate text boxes:

-the starting n

-the ending n

-the step value of n

-the reaction rate

# $ K Differential methods

Perform non-isothermal kinetic parameters evaluation under the ‘differential’ approximations, that is the use of the differential form of kinetic equation. The necessary data may be inserted as temperature vs TG, conversion or DTG (DTA data are used only for Fatu’s method). If is the case, the derivation is made by a three points Lagrange polynomial (not reccommended).

Four computational methods are available:

-Achar et al. (B. N. Achar,G. W. Brindley and J. H. Sharp; Proc. Int. Clay Conf. Jerusalem, 1(1966)67), performs a liniarisation of the kinetic equation written in logarithmic form. The results are very good since no approximations (except the errors you may have in the values of the reaction rate) are made.

-Freeman Carroll (E. S. Freeman and B. Carroll; J. Phys. Chem. 62(1958)394) is one of the best known method. They proposed the use of differences between differentials. This method gives good results only if good quality data are available; for common ones it is unstable (you may obtain even a negative reaction order). The starting reaction order, step, …, are not used in this method.

-Piloyan (F. O. Piloyan, I. O. Ryabchikov and O. S. Novikova; Nature 212(1966)1229), give only the activation energy value.

-Fatu method (D. Fatu; Anal. Univ. Buc, 1997, in press), use the DTA data. The DTA curve is integrated, giving the conversion and reaction rate at different temperatures.

When the Differential methods are selected, you have to introduce in the appropriate text boxes, the followings:

-the starting n

-the ending n

-the step value of n

-reaction rate

# $ K Regression

Here, by this term a least squares routine is designated. The method is based on the solution of an over-determined system equation, reffered here also as pseudo-Inverse matrix method. This method allows the evaluation of non-isothermal kinetic parameters for various conversion functions.

The non-isothermal kinetic parameters evaluations are based (when the integral form of the kinetic equation is used) on various approximation of the temperature integral. However, frequently, only the reaction order conversion function type is supposed. In order to discriminate among possible mechanisms frequently a non-linear regression is used. However, this methods can lead to ill-determined systems. Another difficulty is that the results are biased by the initial estimate of the solution.

The method we propose is to solve an over-determined system equation:

(d/dt)i=ki(T)fi()

where i equations are to be considered. We can directly evaluate the reaction rate or a numeric derivation can be performed to the conversion degree. Thus, by solving this system we can obtain the parameters from Arrhenius expression, k(T) as well as the parameters involved in the conversion function.

The method is based on the pseudo-solution method, i.e. the solution of a over-determined system equations.

Given an m n matrix A, where m>n and an m 1 vector b a vector x can be found, such that Ax is the best estimate of b.

In the case of such over-determined system equations one cannot generally find an exact solution. However, we can find an approximate solution, the x vector which can be evaluated in a least-squares approach such that the residual vector r=Ax-b is minimum [G. Dahlquist and Ake Bjorck , Numerical Methods, Prentice Hall, New Jersey,1974, pp198]. In this case the solution is equivalent to (A*A)x=A*b which can be solved in a classical way; A* is the traspose of the A matrix.

To override a possible ill-conditioned system, a relative large number of equations is required (m > 10 for n= 3 to 4).

Data may be inserted either as conversion, TG or DTG. If it is the case a numerical derivation is performed (the Lagrange interpolation polynomial over three adjacent points). However, your data must be of very good quality in order to obtain good results.

The calculation gives you the activation parameters and the deviation of the free term of equation (experimental-calculated, %) . This is an indication for the quality of the results you have obtained.

# K $ CRTA

CRTA stands for Constant Rate Thermal Analysis. Here, only one alghorithm is used, the ICAR, as it is described in a paper submitted to J. Thermal Anal. (N. D. Dragoe, D. Fatu and E. Segal, submitted in 1997).

It was shown that the temperature of the half-conversion depends on the activation energy and that the shape of (conversion, T) plots depends on the reaction mechanism. A reliable method for the kinetic parameters evaluation is proposed; this method requires at least two decomposition curves, recorded at two different constant decomposition rates.

In order to describe a solid-gaz decomposition reaction, either for the decelaration or for the acceleration, the following form of the reaction rate can be used:

(1)

were the symbols have the common meanings in kinetics. It has to be emphasised that m is the accelerating exponent and n the decelarating exponent (known as the reaction order also).

If m=n=1, the equation (1) becomes the differential form of the Prout-Tompkins equation; for m=0 and n=2/3 the contracting sphere equation is obtained. The decompositions which exhibit an acceleration period can be described by equation (1) with n=0 and m>0. The decompositions which do not exhibit an acceleration period can be described by equation (1) with m=0 and n>0.

If the isokinetic conditions are fulfilled, the reaction rate is kept at a constant value (noted as C); thus the equation (1) can be written as:

(2)

In order to evaluate the activation energy, independently of the conversion function form, we need at least two decomposition curves, recorded at two constant decomposition rates C1 and C2. In isoconversional conditions, the activation energy can be calculated with the formula:

(3)

where the T1 and T2 are the temperature values for the same conversion degree α, recorded at the decomposition rates C1 and C2, respectively. For the (T, conversion) curve, we can obtain the following equations which allows the evaluation of n and m, using the minimum condition at the minimum value of the conversion:

(4)

(5)

The evaluation of the preexponential factor becomes obvious from the equation (1):

(6)

Concerning the equations (4) and (5), one has to note that n and m can not be computed for the points conversion=0, ½ and 1. These difficulties are easily overcomed: n can evaluated for the range 0< conversion<1 with conversion<>0.5 (in the calculation we simply skip this point.). The conversion=0 and conversion=1 conditions, will not interfere with calculations, taking into account that the isoconversion condition can hardly be reached at these particular points.

# $ K The ICAR alghoritm

For other information see CRTA.

We can evaluate the activation parameters from two data sets (Ti, ai) and (T’i, ai) obtained for the decomposition rates C and C’, respectively, based on the above mentioned equations (hereafter the conversion is denoted by a). In order to avoid the difficulty of obtaining Ti and Ti’ for the same ai, a polynomial interpolation schema will be used. This will produce the (T, a) curves independently of the measured values of the conversion and will smooth the data values. The smoothing procedure allows the elimination of the random errors.

The alghoritm consists in:

1. The input data (Ti, ai) and (T’i, ai) for the decomposition rates C and C’ are smoothed by an interpolation polynomial with a degree comprised between 2 and 7. In the usual cases a polynomial degree of 4 is good enough to describe the data. The polynomial coefficients bi and bi’ for each of the recorded curves are computed using the pseudo-Inverse matrix method.

2. The interpolation polynomials once known allow us to compute j values of temperatures T1j, T2j for the two curves, temperatures which correspond to the same values of conversion degree aj. The number of aj values is selected by the user; a suitable value is comprised in the range 20 – 100 (in this version, the program accepts 10 < j < 999). Therefore, we can compute j values of the activation energy using the equation (3) – see CRTA; it is obvious that the activation energy can be computed only for the common aj values corresponding to the two curves. If the Ej values do not vary (in the limit of the experimental errors) it can be concluded that the decomposition process is unique. 3. In order to evaluate the n and m exponents of the conversion function four cases can be considered: a). If the temperature does not vary in the considered domain, the process is independent of n and m, and therefore n=m=0. This case is unusual and somehow superfluous. That is the reason for not considering it. b). If the (a , T) curve has a positive slope then m=0 and n is computed using the formula: where ½ reffers to the half-conversion point. c). If the (a , T) curve has a negative slope then n=0 and m is computed using the formula: (8) d) If the (a, T) curve exhibits a minimum then n>0 and m>0 and their values can be computed with the equations (4) and (5) – see CRTA. If their values do not change with the degree of conversion, this is a proof that the decomposition process is described by a unique conversion function.

In order to calculate the derivatives dT/da, the interpolation polynomial is used.

For the calculations, the decomposition rates in mg/min, the temperature and the mass values in the range where the decomposition rate is constant, are needed. In order to compute the conversion degree and the decomposition rate as sec-1 two other values are requested, namely: the mass values for a=0 and for a=1. The user can input the data as: the decomposition rates in sec-1 and the conversion values for each temperature.

The user can select the degree value of the interpolation polynomial (between 2 and 10) and the number of computation intervals (between 10 and 999). As already stated, for a=1/2, n can not be computed, thus in the program we skip all the a values in the range 1/2-ε < a < 1/2 +ε, we will call hereafter ε as “the exclusion domain”.

The polynomial are calculated with the pseudo-matrix method which is briefly discussed in Regression. The polynomial degree must be lower than the number of data points.

The number of points for the two decomposition rates do not have to be the same, neither the values of the conversion degree nor the values of the temperature.

We emphasise that a higher value of the polynomial degree does not give always the best solution. In fact, smoothing the data means a lower polynomial degree. One has to check the difference between the recorded values of the temperature and the interpolated ones; this difference must be kept at a minimum value. However owing to the smoothing by an interpolation polynomial, the value Σ(Texp – Tcalc) for all α is practically nil. So, the activation parameters are correct only if there are no systematical errors. These errors may arise if the experimental setup is inadequate (too high decomposition rate, too high sample mass,..). In these unfortunate and avoidable cases the results are inaccurate, therefore an analysis of the experimental data before doing calculations is a good experimental practice (it is worth noting thata if the errors are the same for each curve, the value of the activation energy is not strongly affected).

# $ K The Data Editor – The data grid

This is the region containing the most important data. You can insert temperature (either C or K) and conversion (or TG, DTG, DTA – depending on the methods, some restrictions may apply). There are two combo list boxes for selecting the data type.

You can input data in few ways:

-by writting it at the keyboard

-by opening a data file

-by inserting an ASCII file

-by reading a picture file

Advice: do not insert negative values (for some reasons the program will not accept the negative values). You can modify your data inserting (CTRL+INS) and deleting (CTRL+DEL) data rows.

Check carefully your data before making any calculations.

# $ K The Data Editor – Estimated error text field

In this text field, the estimated error in the conversion function must be inserted. The values is in percents (%) and must be lower than 10 % (why should you compute data with a such large error ?).

However, this value is used only for integral and differential methods. It is used to compute the standard deviation terms for the calculated parameters. In this program a simple error propagation routine is used but, in my opinion, the real standard deviation is always (much) higher that the obtained values.

In practice, the error in the conversion degree is between 1% and 3%. (do not believe the salesman and do not forget the factors that affect your measurements).

# $ K The Data Editor – The experiment name

This text field is in the lower right part of the window. It is reccomended to write something there in order to remind the calculation you have done.

# $ K The Import Form

The import form is a routine for those who do not have high competitive aparatus and the data are still recorded on the paper. This routine is also useful for those who want to re-analyse old experimental data.

In this form there is a menu, consisting of:

-File

-Open

-Open a bitmap file, which will be used for a manual data reading. Depending on the resolution of this file you may have problems with resizing or even opening it. A 150 or 300 dpi resolution will do the job.

-Exit

Exit this form

-Help

This help file is showed.

In the left side of the panel you will see:

-Add values

-Set scale,

as well as some labels

# K $ The Import Form – Add values

This button will add the values (written in red) into the data editor. These are the last coordinates of the click event in the picture.The values will depend on the scale you used by the Set scale command. They are not automatically added to the data.

Below these values, two other labels, with a blue text are visible: these are the current coordinates of the mouse.

If you don’t have a user defined scale, this button will be disabled.

When you resize the Import form, you have to redefine your scale.

# $ K The Import form – Set scale

This is the first operation you have to do before inserting data. Because I don’t know your screen resolution or the picture resolution you have to define your own scale before proceeding any further (you’ll have to redefine your scale after resizing your form too).

In order to define your own scale click on this button (or use the ALT+S command). An information window will appear suggesting to click twice wherever you want on the screen. The relative position of the click events will be showed (with no meaning for the user). You will have to fill the four corresponding text boxes the appropriate values for X1, Y1 and X2 , Y2. Depending on the values you insert, the relative position are written in blue. If you want to select a point: click on it, the red values are recorded and will be written in the data editor when you’ll click to the Add Button.

In blue the current coordinates of the mouse are printed.

# K $ The Graphics Form

This is a graphic routine; very useful for inspecting the data values as well as the computed or simulated data. The available commands are:

-Graphics

Draw

Copy

Print

Export as ASCII

Exit

-Edit

Inspect

Style

-View

Computed

Simulated

Experimental

ICAR

Simulate new

-Help

This help file is showed.

# $ K The Graphics Form – The Graphics Menu

Draw

Paints the graphic according to checked menus in the View menu. If you haven’t selected what to draw this command has no effect.

Because the experimental points are plotted with a particular shape (square, cross, etc..) the plotting procedure may take a while. Be patient.

Copy

There are three possibilities to Copy the graphic:

-To Clipboard – the graphic is copied into the Clipboard, use Paste or Ctrl+V in other program to retrieve it.

-To Printer – the graphic is printed to the printer with a screen resolution (less than 100 dpi). The size of the printed graphic depends on the size on the screen.

-To File – the graphic is saved as BMP file at the screen resolution. This bitmap file can be modified with other programs (like Paintbrush, for instance). However, the resolution you obtain can be disapointing.

Print

-Print a full page graphic at the printer resolution. Reccomended when you want good quality output. Remember that you will not obtain the same graphic as painted on the screen (the lines and the points printed are at least three times smaller than those on the screen).

Export as ASCII

All data are exported in an ASCII format file. Useful for treating data with a more powerful graphic program.

Exit

Exit the graphic routine and return to the main part of the program.

# $ K The Graphics Form – The Edit Menu

Inspect

If this menu is checked, the X and Y current position of the mouse are printed to the screen in two yellow labels.

Style

Changes the style of the graphic. Here, you can change the X and Y domain, the colors and sizes for the points or lines. There are seven different shapes for the data point: circle, filled circle, cross, x, square, filled square and diamond. To changes the shape style click of the shape numbers or labels.

If you don’t want a graphic to be plotted, uncheck the corresponding item in the View menu or make the size of the line and the points equal to 0.

# $ K The Graphics Form – The View Menu

The data are displayed always as (temp. /K, conversion) or (conversion, temp. /K) for CRTA data, no matter the input data was.

Computed

Shows the computed (temp. /K, conversion), if you have done some calculations.

Simulated

Draws the simulated curve; enabled only if you have simulated some data.

Experimental

Draws the (temp. /K, conversion) of the experimental point

ICAR

Draws the experimental and the interpolated (alpha, Temp. /K) curve obtained in the CRTA procedure as well as the difference between the experimental and interpolated data. Remember to change the graphic domain in order to see what you want. Here the graphic is plotted as (conversion, temp. /K).

Simulate new

Simulate (T, conversion) or (alpha, Temp. /K) data and put it on the screen. You can not simulate CRTA data unless a compuation in CRTA is made.

# $ K The Main Form

This is the main part of the program. In fact, the form consists of a results text field you can edit, print… All the calculations are added in this text. The available commands are:

-File

-Notepad

-Wordpad

-Printer

-Quit

-Data

-Open

-Edit

-Print

-Save as

-Results

-Format

-View

-Discard

-Copy to Clipboard

-Send to Wordpad

-Save

-Compute

-Parameters

-Graphics

-Simulation

-Help

-About

-Contents

-Search

-Help on Help

# K $ The Main Form – The File menu

The available menus are:

-Notepad

Opens a new session of the Notepad program for editing a data file, etc…This is a Window shell session, this program will not be closed when you quit Versatile.

-Wordpad

Opens a new session of the Wordpad program for editing a file, etc… This is a Window shell session, this program will not be closed when you quit Versatile.

-Printer Setup

Opens the Printer Setup form. Attention: the changes you made here become permanent.

-Quit

Quit the program (but not the eventually other programs opened from here.)

# $ K The Main Form – The Data menu

The available commands are:

-Open

Opens a data file, and insert the data in the data editor.

-Edit

Opens the data editor session in order to input, edit or modify the data values.

-Print

Prints the data values (the same command you can find in the data editor).

-Save as

Saves the data file (the same command you can find in the data editor).

# K $ The Main Form – The Results menu

All commands available here, are reffering to the results. These are:

-Format

Change the appearance of the selected results text (you can change the fonts, colors or size). You can select a part of this text by dragging it with the mouse or with Shift+Arrows keys.

-View

Toggle the visibility of the results. The results are still in memory but you can display them or not.

-Discard

Discard and lose all the results. A dangerous action, take care !

-Copy to Clipboard

Copy the results to the Clipboard (the results file may be very large so do not waste the computer memory unless you want to paste the contents of the Clipboard somewhere)

-Send to Wordpad

Send the results file to the Wordpad. Here you can edit the results, print or save, etc.

Attention: if you want to make this operation be sure that the Wordpad isn’t opened with the same procedure. In fact, by clicking on this menu, a results file (always named _vrsat.rtf) is saved in the current directory in a RTF format, then the Wordpad opens this file. Be sure that you close the Wordpad (or the file) before doing this a second time.

If you haven’t the Wordpad installed or any another unexpected error occurs, you can use the vrsat.rtf file with another program that can read the RTF format (such as MS-Word). The RTF file contains any changes you have made in the fonts, colors…

-Save

Saves the results in a plain text file (save your results before closing or erasing them; you may want them at a later time).

# $ K The Main Form – The Compute menu

Three comands are available:

-Parameters

Computes the kinetic parameters as described in the data editor. If something goes wrong check your data.

If this command is disabled, it means you have no valid data.

-Graphics

Opens the Graphics form.

-Simulation

Opens the Simulation form in order to simulate (temp, alpha) values.

# $ K The Main Form – The Help menu

In this menu, two commands are available:

-About, which opens an About… window

-Contents

-Search

Search the Versatile 1.00 Help file for a keyword. Available also in the Help window.

-Help on Help

A comprehensive description of the Help functions in Windows.

# K $ The Simulation form

The simulation form can be opened either from the main part of the program or from the graphics window. Depending on the way you open this form, the results are displayed as printed data or in a graphic form. The purpose of this form is to simulate data for the “reaction order” kinetic model or for CRTA conditions.

There are three menus available

-OK

If the data are required as ASCII values (i.e. you opened the simulation from the main part of the program) this means the confirmation of the kinetic parameters, the temperature and conversion are computed and the form is closed.

If you are in the graphic routine, the graphic is repainted each time you change some values and click the OK menu (the graphic is also repainted after each click on a spin buton).

-Close

This command will close the simulation form.

-Help

This help file is showed. For a context sensitive help press the F1 key.

Always 200 pairs of data points are simulated.

There are few text fields which are explained here:

-n

-m

-Exponential factor

-Activation energy

-Reaction rate

-Starting temperature

-Ending temperature

-Number of the p(x) terms

Each text field is associated with spin buttons, their role being to increase or decrease the corresponding value in the text field (the text can be edited in the classic way). The increment for the spin buttons (it is preferably to use these spin buttons in the graphic form) is given by the position of the slider from the right part of this window.

Note: You can not simulate in a graphic some CRTA data unless you already made a calculation under CRTA condition.

# K $ The Simulation Form – n value

This is the value of n (the reaction order) used to simulate data. If the CRTA check box is checked, the data are simulated as (conversion, temperature) with the CRTA equations.

The expression for conversion function is (here, x is the conversion).

f(x)=x^m (1-x)^n

Otherwise, the reaction order model is used to generate 200 pairs of data points. The expression for the conversion function is in this case:

f(x)= (1-x)^n

The accepted values of n are between 0 and 3. You may want to change its value through the spin buttons: the used increment is established by the Slider.

Attention: if the value for n is 0.0, the increment will be always 0.0 no matter the Slider value (in this case, use the classic way to change a text box). The same rule applies for others text fields.

# K $ The Simulation Form – m value

This is the value of m used to simulate data, the expression for the conversion function is (x is the conversion).

f(x)=x^m (1-x)^n

It is used only in the CRTA mode to generate 200 pairs of data points.

The values accepted for m are between 0 and 3. You may want to change its value through the spin buttons: the used increment is established by the Slider.

Attention: if the m value is 0.0, the increment will be always 0.0 no matter the Slider value (in this case, use the classic way to change the m value).

# K $ The Simulation Form – Preexponential factor

This is the value of the preexponential factor from the Arrhenius equation:

k=A exp (-E/RT), where

k is the specific rate, A is the preexponential factor, E the activation energy, T is the absolute temperature and R is the gaz constant (8.31 J/moleK).

# K $ The Simulation Form – Activation energy

This is the value of the activation energy from the Arrhenius equation:

k=A exp (-E/RT), where

k is the specific rate, A is the preexponential factor, E the activation energy, T is the absolute temperature and R is the gaz constant.

In this text box, this value is inserted as kJ/mole (the accepted values are from 10 to 600 kJ/mole).

# K $ The Simulation Form – Reaction rate

This is the reaction rate used to simulate the data points. It is either in K/min for the constant heating rate or as 1/sec in the CRTA mode.

# K $ The Simulation Form – Starting temperature

This value is used only for constant heating rate processes; the temperature interval is divided in 200 values in order to calculate 200 pairs of data.

# $ K The Simulation Form – Ending temperature

This value is used only for constant heating rate processes; the temperature interval is divided in 200 values in order to calculate 200 pairs of data.

This value can not be lower or equal to the starting value of the temperature.

# K $ The Simulation Form – The number of p(x) terms

This value is used only for constant heating rate processes. The conversion degree is calculated from the equation:

F(alpha)=AE/aR p(x), where alpha is the conversion, F(alpha) is:

(1-(1-alpha)^n)/(1-n) if n <>1 or

-ln (1- alpha), for n=1.

A is the preexponential factor, E the activation energy, a the heating rate and R the gaz constant. P(x) is the approximation of the temperature integral:

p(x)=e^x /(x^2) (1+2!/x+3!/x^2+4!/x^3 +…+)

The precision of the conversion degree is somehow dependent on the number of terms in the series (it must be lower than -x, where x=-E/RT)

# $ K The Simulation form – Slider

By dragging the indicator, you can change the size of the increment value when the user clicks a spin buton.

# K $ Copyright notice

Companies, names and examples used here may have their copyright. No part of this document may be reproduced or transmitted in any form or by any means (unless for your personal use only) whitout the express written permission of the author.

Microsoft, MS-DOS, Windows, Windows NT, Visual Basic are trademarks of the Microsoft Corporation.

# $ K The Author

This program is a (much developed) variant of the Versatile, as was described in N. D. Dragoe and E. Segal; Thermochim. Acta 185(1991)129.

Please read the help file before making a problem report ( read also copyright notice ).

The correspondence should not be submitted by electronic-mail.

For a problem report use a concise but comprehensive description, such as:

-the title of your problem

-the date

-the module name

-the error description as appear in the program

-the program version and licence number

-the type of the problem:

-software

-help file

-other

-the comprehensive description of the problem you encounter

-enclose all relevant information:

-the computer you have, operation system, etc.

-the data file, the methods, etc.

-when was this problem noticed

-can you recover ?

-is the problem repeatable ?

# $ K The purpose of the program – Versatile 1.00

This program is designed to be used by scientists or students working in the field of non-isothermal kinetic analysis. No part of this program or documentation may be used for commercial purposes without the express written permission of the author.

It runs under MS-Windows 95 or NT only.