The CPS-Simulation Document holds an arbitrary number of ComPosed Scan - voltammetric simulations. The term "composed scan voltammetry" is used here for describing a voltammetric experiment composed of a arbitrary sequence of CA-, CV and/or SW-scans. To provide an example, an experiment where a stripping step (in which a metal-ion is reduced on a mercury drop electrode by forming an amalgam) is executed before running a conventional CV-experiment can be considered a CPS-experiment composed of a CA-scan and a CV-scan. That means, the stripping step is simulated in terms of a chrono-amperometric experiment and the concentration profiles referring to the end of the CA-scan are used then for simulating the current response of the cyclic voltammogram. Another example of a CPS-voltammetric experiment is a CV running the forward scan in the usual way but then the scan is paused for a certain time before starting the revers scan. Such an experiment can be simulated in terms of a CPS-simulation composed of a CV-scan (moving from Estart to Erev), a CA-scan (jumping from Erev to Erev and applying this constant potential for the pause time) and the reverse CV-scan (moving from Erev back to Estart).
The current curves associated with these simulations are simultaneously displayed in the Client Area of the Tab-Window headlined Simulations. The current curve referring to the active simulation (this is the simulation to which the menu commands in the Ribbon Bar refer) is plotted in black while the current curves of the inactive simulations are plotted in green by default. The default color settings and some other options for plotting the current curves can be customized in the associated Properties windows.
The concentration profiles simulated for the active simulation are shown in the Tab-Window headlined C-Profiles while the simulated surface concentrations are shown in the Tab-Window headlined Surface Concentrations. The latter also provides the option to display the surface coverage if there is at least one redox couple comprising adsorbed species.
The menu commands available when activating the Tab-Window: Experiments enable the user to import experimental data files and to prepare the imported files (if necessary) before using them in a Data Fitting Project. The fitting procedure can be started in the Tab-Window: Data Fitting. The fitting procedure is based on a non-linear regression strategy aimed at minimizing the overall standard deviation between simulated and experimental current curves by modifying the thermodynamic and kinetic parameters of a user-defined mechanism in an iterative way. As long as the fitting procedure is running, a comparison between the currently simulated current curve and its experimental counterpart is shown in the Tab-Window: Data Fitting. If the fitting procedure has terminated the user may want to see how well the simulated current curves agree with the experimental ones. All selected couples (experimental current curves and their simulated counterparts) are shown in the Tabbed Window: Compare Curves. The user may also want to know how strongly the overall standard deviation between simulation and experiment is affected when varying one particular parameter. This information can be computed and displayed in graphical form in the Tabbed Window: Chi²-Tests.
The Tab-Window: Plot Graph can be used for plotting data (x,y-couples) in graphical form. The x-y-couples can be either directly entered using the editor provided for this Tab-Window or imported from the screen info shown on other Tab-Windows after applying the Plot Graph command. The screen info is obtained either by means of the Min/Max Info command or by retrieving the screen coordinates of individual points by double clicking on the a particular current point of the active curve (see video Getting Started for more details).
