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The Quantum Hall Plateau-to-Plateau transition is a long-standing problem that has not yet been solved. Around the critical point, very different critical exponents of the localization length have been gotten experimentally. We approach this problem by doing experiments in the alloy disorder, which is realized in the Al_xGa_1−xAs-Al_0.32Ga_0.68As heterostructure. By measuring directly the alloy scattering rate, we found the alloy disorder to be strong (1.13eV), short-range (atomic size) and temperature-independent3. By controlling the Aluminum concentration x, we make systems dominated by the short-range alloy disorder, where quantum mechanics prevails. In these systems, the scaling exponent is observed to be 0.42.

Magnesium alloys still have a lot of technical challenges to be solved for more applications. There have been many research activities to enhance formability of magnesium alloys. One is to design new alloy composition having better formability. Also, low formability of wrought alloys can be improved by optimizing the processing variables. In the present study, effect of process variables such as forging temperature and forging speed were investigated to forgeability of three different magnesium alloys such as AZ31, AZ61 and ZK60. To understand the effect of process variables more specifically, both numerical and experimental works have been carried out on the model which contains both upsetting and extrusion geometries. Forgeability of magnesium alloys was found to depend more on the forging speed rather than temperature. Forged sample showed a significant activity of twinning, which was found to be closely related with flow uniformity.