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The Kowloon-Canton Railway has opened two new suburban rail routes in Hong Kong. Initially, these lines used the high-conicity P8a wheel profile and the UIC60 rail profile. Problems were experienced with the wheel/rail interface, including disappointing wheelset life, high vibration due to hunting instability and rapid growth of rolling contact fatigue (RCF) damage on the high rail in curves. Careful analysis using established wheel/rail interface modelling techniques and innovative validated RCF prediction algorithms has led to the development of an optimised wheel/rail interface. The combination of the low-conicity P8y wheel profile and the CEN60-E2 rail profile, with effective lubrication, has given substantial improvements in re-profiling intervals, improved running stability and has led to a massive reduction in RCF damage. [ABSTRACT FROM AUTHOR]

We have performed molecular dynamics simulations for a total duration of more than 10 µs (with most molecular trajectories being 1 µs in duration) to study the effect of a single mutation on hen lysozyme protein stability and denaturing, using an IBM Blue Gene/L™ supercomputer. One goal of this study was to assess the use of certain force fields to reproduce experimental results of protein unfolding using thermal denaturing techniques. A second and more important goal was to gain microscopic insights into the mechanism of protein misfolding using both thermal and chemical denaturing techniques. We found that the thermal denaturing results were robust and reproducible with various force fields. The chemical denaturing results explained why the single amino-acid mutation on residue Trp62 causes the disruption of long-range interactions in the tertiary structure. Simulation results revealed that the Trp62 residue was the key to a cooperative long-range interaction within the wild-type protein. Specifically, Trp62 acts as a bridge between two neighboring basic residues through a φ-type H-bond or φ--cation interaction to form an Arg-Trp-Arg ''sandwich-like'' structure. Our findings support the general conclusions of the experiment and provide an interesting molecular depiction of the disruption of the long-range interactions. [ABSTRACT FROM AUTHOR]