Root caps provide a protective layer in front of the meristem that protects the meristem from abrasion by soil particles. The continuous production and sloughing of the root cap cells may be an adaptation to decrease the friction at the soil-root interface by acting as a low-friction lining to the channel formed by the root. Experiments were performed which provide the first direct evidence tha...

A time-free, drift-free, multi-dimensional model of friction is introduced. A discrete implementation is developed which exhibits four solution regimes: sticking, creeping, oscillating, and sliding. Its computational solution is efficient to compute online and is robust to noise. It is applied to haptic rendering.

A time-free, drift-free, multi-dimensional model of friction is introduced. A discrete implementation is developed which exhibits four solution regimes: sticking, creeping, oscillating, and sliding. Its computational solution is efficient to compute online and is robust to noise. It is applied to haptic rendering.

ABSTRACT: We investigate the dynamics of monopole annihilation by the LangackerPi mechanism. We find that considerations of causality, flux-tube energetics and the friction from Aharonov-Bohm scattering suggest that the monopole annihilation is most efficient if electromagnetism is spontaneously broken at the lowest temperature (Tem ≈ 106 GeV) consistent with not having the monopoles dominate t...

A new procedure for deriving nonlinear mathematical modeling for a specific class of aerospace hydro - mechanical control valves is presented. The effects of friction on the dynamic behavior of these types of valves along with the experimental verifictions are also given. The modeling approach is based on the combination of the following three tasks: decomposition of the valve into simple speci...

Amagnetohydrodynamic flow of a viscous, incompressible and slightly conducting fluid is developed between a parallel flat wall and a wavy wall whereas at the same time fluid is continuously sucked through the flat wall with a constant suction velocity. The velocity and temperature distribution are determined alongwith the pressure gradient and co-efficient of skin friction.

A physically based model of the frictional interaction between dry surfaces is presented. The paper reviews a number of static and dynamic friction models, and discusses numerical techniques for the accurate and efficient numerical implementation of a dynamic elasto-plastic model. An application to the bowed string is provided, and the resulting simulations are compared to recent results from t...

Friction plays a fundamental role in the Mechanics of granular materials. Two problems are considered: (i) heap formation, (ii) granular flow. Both problems admit closely related mathematical models. In each case, analytical and numerical difficulties are discussed. Efficient and reliable numerical methods are proposed and implemented. The results are illustrated by several computational experi...

in this research, an apparatus was made and utilized to determine the friction coeffi-cient of chickpea grains on steel surfaces. experiments were carried out on two black and galvanized surfaces and at four sliding velocities of 5, 20, 100 and 500 mm/min, at three moisture content of 7.5%, 15% and 21% wet basis (w.b.) and at three vertical pressure values of 14.28, 100 and 150 kpa. the followi...