EDUCATIONAL APPLETS*

Analytical Chemistry - General Chemistry

Distribution diagrams of polyprotic acids

Draw plots of the concentration fractions of polyprotic acids species as

functions of pH. [2000/04]

Distribution diagrams of metal complexes

Draw plots of the concentration fractions of successive complexes

ML, ML2, .... MLn as a function of log[L]. [2003/01]

Acid-Base titration curves

Draw the titration curves expected for titrations of a number of real acids and bases at any combination between each other and at any concentration level. [2000/05]

Periodic table of elements and correlation plots of their properties

Inspect the numerical values of a number of properties of the chemical elements and create correlation plots between any two of these properties. [2000/07]

Instrumental Chemical Analysis

Deviations from Beer's Law:

Effect of polychromatic radiation

Observe the effect of the selected wavelength and of the bandwidth of the incident radiation beam on the absorbance vs. concentration plot. [2001/06]

Isotope peaks of ionic fragments in mass spectrometry

Insert the empirical formula of an ionic fragment and obtain the relative intensities of its isotope peaks. Ībserve the lines corresponding to this fragment, as they would appeared in a mass spectrum. [2000/11]

Counter-current extraction - Craig apparatus

Simulated separation of a mixture of two substances by counter-current extraction using a Craig apparatus. [2000/04]

Chromatographic separations

Simulation of the separation of a mixture of 5 substances across a chromatographic column and of the recorded chromatogram. [2000/04]

Diffusion controlled electrode processes

Observe the consumption and the production of particles participating in a reversible electrode reaction, their corresponding concentration profiles and

the effect of the potential of the working electrode. [2002/12]

Instrumentation - Signal Processing

Analog electronics: Basic circuits of operational amplifiers

Examine the operation of the following circuits of operational amplifiers:

inverting amplifier, summing amplifier, difference amplifier, differentiator,

and integrator. [2002/04]

Digital electronics: gates, decoders, multiplexers

Examine the 'truth tables' of digitals gates and the propagation of logical states through some simple circuits combining various gates. [2001/04]

Signal smoothing algorithms

Improve the signal-to-noise ratio of various signals by the moving average, Savitzky-Golay and ensemble average techniques. [2000/04]

Fourier synthesis of periodic waveforms

Observe the gradual formation of some periodic non-sinusoidal waveforms by successive point-to-point additions of sinusoidal functions. [2000/04]

Fourier analysis and signal filtering

Obtain the frequency spectrum H(f) of a signal h(t) using a Fast Fourier

Transform (FFT), and observe the effect of clipping of certain frequency

bands on the original signal. [2000/11]

Data Analysis - Chemometrics

Student's t-test for comparison of two means

Observe the outcome of this statistical test for various pairs of data sets,

which you can easily define. [2003/12]

Dixon's Q-test for the detection of a single outlier

Define sets of values of replicate measurements and examine if one of them in each set can be rejected as an outlier or not. [2006/05]

Least-squares polynomial approximation

A demonstration of the m-degree (m equal or less than 12)  polynomial least-squares regression on data sets defined by the user. [2003/12]

A non-parametric regression method

Try a non-parametric regression method (Theil's Incomplete Method) to fit a straight line to data points and compare the results with those obtained with

the least-squares regression method. [2003/12]

Simplex optimization

Observe how Simplex algorithm is searching for the global minimum through a 2-dimensional parameter space. [2000/04]

Central limit theorem

Observe how the population of the mean values of N measurements, obtained from populations of any distribution, gradually tends to be normally

distributed as the number N (sample size) increases. [2005/11]

Drunken sailor's random walk

An introductory example on Monte Carlo simulations: Calculation of probabilities

of the arrival of a "drunken sailor" to each one of a town exits. [2000/04] 

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(page maintained by Prof. C.E. Efstathiou)