Whole industries currently rely on bulk-grown crystals of a variety of materials. These industries range from information technology, based on the ubiquitous silicon, through radiofrequency applications, using gallium arsenide, etc.,'to telecommunications and lighting, based on III-V compounds, to infrared imaging, based on cadmium mercury telluride, and to high-energy physics and medical imaging using scintillator materials. These materials are used either in the active mode, as for silicon, or in the passive mode where the bulk-grown material is used as a substrate on which to deposit a wide range of binary, ternary, quaternary, etc., compounds by several epitaxial growth processes.

Anyone who takes the trouble to look up all the entries that have been filed under "Calcium Carbonate" in a university library will be surprised - if not overwhelmed - by the enormous amount of literature that is concerned in one way or another with this subject. Most of the corresponding books and journals can be assigned to the realms of chemistry, but they also include technical, geological and mineralogical literature. A continued search will eventually unearth works on the history of the arts and architecture. This is because calcium carbonate minerals, be they in the form of chalk, limestone or marble, symbolize defining moments in the history of our culture - the first prehistoric cave drawings in simple coloured chalk, the gigantic limestone blocks used to build the Egyptian pyramids and the marble statues of Michelangelo and Bernini.

PEST stands for “parameter estimation”. When it was originally written in 1994, this is all that PEST did. However over the 20 years that have elapsed since then, the capabilities of the PEST suite of software have expanded enormously. The emphasis has shifted from inversion to inversion-constrained model parameter and predictive uncertainty analysis.