ABSTRACT
Acknowledgements............................................................................ 490
Glossary of Sym bols.......................................................................... 491
References............................................................................................. 491
1 Introduction
For materials with structural organisation on different length scales which are being studied while they are perturbed by either thermal, chemical or mechanical methods the simultaneous application of time resolved Small Angle X-ray Scattering (SAXS) and Wide Angle X-ray Scattering (WAXS) can be very useful to elucidate their phase transitions and the mechanisms driving these transitions. A prime example of this are the phase transitions in semi-crystalline polymers subjected to temper ature jumps or mechanical deformations but numerous other systems in both biology or material science can be mentioned.