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Low adhesion in the wheel/rail contact is a problem for the rail industry in Great Britain as it causes significant scheduling and safety issues. Applying sand to the wheel/rail contact is used to mitigate against low adhesion however, there is not a consensus on what makes a "good" particle for restoring adhesion, especially with regards to when the particle has entered the wheel/rail contact. The aim of this work was to investigate what particle characteristics had the greatest effect on wheel/rail adhesion and surface conditions, using a process of particle characterisation, tribological testing and statistical modelling. Particle size, shape, and hardness were all found to affect tribological performance. This knowledge can help guide future changes to sanding operations. • Multiple types of particle used in the sanding process characterised. • Tribological tests assessing the impact of sand on leaf layers. • Effect of particle characteristics on friction in high pressure interface. • Effect of particle characteristics on surface roughness in high pressure interface. [ABSTRACT FROM AUTHOR]

Adaptations to the humeral torsion angle have been identified in the professional throwing athlete. This movement pattern increases the humeral torsion angle, and also increases the extent of external rotation movements in the dominant, throwing limb when compared with the nondominant limb. The purpose of this paper is to test the hypothesis that the humeral torsion angle is an adaptation to upper limb use. This project examines the humeral torsion angle in a number of medieval British populations, as well as a modern cadaver-based sample. The results identify significant differences in the humeral torsion angle both between and within male (P < 0.001, ANOVA) and female (P < 0.014, ANOVA) populations, although the results are not consistent with expected behavior pat- terns. Statistically significant differences between males and females within the same site were identified in 2 of the 5 samples examined. The mean level of bilateral asymmetry does not approach that reported for the professional throwing athlete. However, a number of individuals have high levels of asymmetry in excess of that identified in the professional throwing athlete. This analysis demonstrates the need for individual rather than population-based analyses, as the heterogeneity within population samples obscures individual variation in activity patterns. The diversity within British medieval society and a lack of specific known behaviors prevent further identification of the functional significance of the humeral torsion angle within the archaeological record examined here. [ABSTRACT FROM AUTHOR]

Low adhesion between a train's wheel and the rail can cause performance and safety issues, costing the UK rail industry ~£345 m/annum. Sand is applied to the wheel/rail interface to increase traction when low adhesion conditions are present. In order to improve performance, an understanding of how particles are entrained into and act within the interface is needed. This paper outlines a particle characterisation framework and applies it to sands used in the rail industry: Leighton Buzzard (LB), Central European (CE), and Derbyshire Youlgreave (DY) sand. The largest difference found in this framework was between the sand's particle size, LB being largest, then CE, then DY. A high pressure torsion rig measured traction when the sands were applied to dry, wet, and leaf extract contaminated conditions, the latter two representing low adhesion conditions. All sands had no impact on wheel/rail adhesion in dry conditions; in low adhesion conditions DY had little influence, whereas LB and CE were found to increase traction. Particles in dry conditions had no effect on test specimen surface roughness, whereas roughness increased when sand was applied in low adhesion conditions. The developed characterisation framework provides a platform for assessing prospective adhesion enhancing particles. • A particle characterisation framework has been designed for rail sand. • Three sands used in rail research were characterised. • In a small scale tribological test, the larger sands recovered adhesion better. • In low adhesion conditions the sand increased specimen surface roughness. [ABSTRACT FROM AUTHOR]