OBJECTIVE To investigate the effects of lubricin gene dosage and cyclic loading on whole joint coefficient of friction and articular cartilage surface integrity in mouse knee joints. METHODS Joints from mice with 2 (Prg4(+/+)), 1 (Prg4(+/-)), or no (Prg4(-/-)) functioning lubricin alleles were subjected to 26 hours of cyclic loading using a custom-built pendulum. Coefficient of friction value...

nt matter & 2007 IAgrE. temseng.2007.02.013 thor. Tel.: +1 217 333 2854; : [email protected] (T.E. Gri This paper describes the development of a device capable of measuring the dynamic friction coefficient of particles accelerated in a tube spinning in a horizontal plane. The dynamic friction coefficient is not the classical Coulomb friction coefficient, but a lumped parameter influenced by the Co...

Lubricants ordinarily operate by keeping two sliding surfaces separated. The efficiency of a lubricant may be expressed by equations of hydrodynamics where the mechanical properties of the films of lubricants are adequately defined by the properties of bulk lubricant. In the case of water lubrication of black rubber at slow speeds and low pressures the lubricating ability of water is shown to b...

The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were per...

Tire/road interactions play a critical role in safe operation of ground vehicles. This paper presents the modeling, analysis, and experimental studies of stick–slip interactions between the stationary tire and the firm road. A semi-analytical model is first proposed to predict the normal force distribution on the tire contact patch. A beam–spring network modeling approach is then used to captur...

The paper aims at investigating the effects of chemical reaction and thermal radiation on the steady two-dimensional laminar flow of viscous incompressible electrically conducting micropolar fluid past a stretching surface embedded in a non-Darcian porous medium. The radiative heat flux is assumed to follow Rosseland approximation. The governing equations of momentum, angular momentum, energy, ...

The process of size segregation in a model system of granular matter, consisting of 1600 spherical poly-disperse particles stirred by a rectangular bar moving periodically in the horizontal direction, was modelled by the discrete element method under different values of dynamic friction coefficient of the particle material. It has been shown that the dynamic friction coefficient influences the ...