Hearing starts when sound-evoked mechanical vibrations of the hair-cell bundle activate mechanosensitive ion channels, giving birth to an electrical signal. As for any mechanical system, friction impedes movements of the hair bundle and thus constrains the sensitivity and frequency selectivity of auditory transduction. Friction is generally thought to result mainly from viscous drag by the surr...

C. G. Johnson, J. M. N. T. Gray (2010), J. Fluid Mech., (Submitted) • “Weak, strong and detached oblique shocks in gravity driven granular free-surface žows”, J. M. N. T. Gray, X. Cui (2007), J. Fluid Mech., 579, 113–136 • “Dežecting dams and the formation of oblique shocks in snow avalanches at Flateyri, Iceland”, X. Cui, J. M. N. T. Gray, T. Johannesson (2007), J. Geophys. Res., 112, F04012 •...

We report the results of a direct comparison of the adhesion, friction, and mechanical properties between alkanethiol self-assembled monolayer films terminated by either CH(3) or CF(3) end groups using both interfacial force (IFM) and atomic force (AFM) microscopies. The purpose of this work is to gain insight into the detailed origins of the differing frictional behavior previously observed wi...

We have made reliable measurements of the sound velocity delta v/v(0) and internal friction Q(-1) in vitreous silica at 1.03, 3.74, and 14.0 kHz between 1 mK and 0.5 K. In contrast with earlier studies that did not span as wide a temperature and frequency range, our measurements of Q(-1) reveal a crossover (as T decreases) only near 10 mK from the T(3) dependence predicted by the standard tunne...

The Savage-Hutter (SH) avalanche model is a depth-averaged dynamical model of a fluid-like continuum implementing the following simplifying assumptions: (i) density preserving, (ii) shallowness of the avalanche piles and small topographic curvatures, (iii) Coulomb-type sliding with bed friction angle delta and (iv) Mohr-Coulomb behaviour in the interior with internal angle of friction phi> or =...

In this paper we correlate the Atomic Force Microscope probe movement with surface location while scanning in the imaging and Force versus distance modes. Static and dynamic stick-slip processes are described on a scale of nanometres to microns on a range of samples. We demonstrate the limits and range of the tip apex being fixed laterally in the force versus distance mode and static friction s...

Slope stability is one of the most important issues in open pit mining design. The main purpose of any open pit mine design is to propose an optimal excavation configuration, considering safety, ore recovery and financial return. An accurate pit slope design which accounts for the mine geology, structural geology, rock mass properties, and hydrogeology models of the mine area, drastically enhan...

The effect of C60 molecular rotation on the nanotribological properties of C60 single crystal surfaces has been studied by atomic/frictional force microscopy. The orientational order-disorder phase transition, in which the high temperature C60 free rotation is reduced to a low temperature hindered rotation, is shown to give rise to an abrupt change in friction and adhesion. This change in frict...

We present experimental results on continuously supplied and well developed gravity currents moving from horizontal to concave or constant-slope boundaries. Results show that the gravity current velocity is in continuous spatial development and approaches an equilibrium state velocity only when the slope change is small. Following closely the theory of Turner (1973) we derive a general equation...

The quantification of flow resistance in complex natural channels continues to be a key source of uncertainty in basic research, engineering, and environmental management. This paper describes a meta-analysis of data compiled from a wide range of sources and flow conditions in mountain streams that compares the accuracy of equations developed by Jarrett (1984), Hey (1979), Bathurst (1985) and B...