Measurements of the normal reaction force and the friction force acting on an obliquely bouncing ball were made to determine whether the friction force acting on the ball is due to sliding, rolling, or static friction. At low angles of incidence to the horizontal, a ball incident without spin will slide throughout the bounce. At higher angles of incidence, elementary bounce models predict that ...

Interlayer rotation angle couples strongly to the electronic states of twisted van der Waals layers. However, not every is energetically favorable. Recent experiments on rotation-tunable electronics reveal existence a discrete set angles at which assume most stable configurations. Nevertheless, quantitative map for locating these intrinsically preferred twist in bilayer system has been availabl...

in this work, experimental studies of internal friction coefficient and porosity of four high productive rice varieties in iran (nemat, neda, pajouhesh and pardis) have been presented. moisture content varied in four different ranges between 8 and 20%. the obtained results indicated that the internal friction coefficient decreased with increasing the moisture content from 8 to 11%, then decreas...

For the sustainability of lignite and coal mining, engineers need soils' appropriate geotechnical characterisation excavations. This relates to slope stability, overall area sustainable exploitation mining areas during operational post-closure eras. work presents a novel perspective on soil mine Rather than focusing one particular mine, comprehensive provides insights about soils related areas....

A friction coefficient is defined as the ratio of the friction force to the applied normal force. Despite the disarming simplicity of its calculation, there are practical challenges that make low values of friction coefficient difficult to accurately quantify. The connections of imperfect parts in friction measurement devices (called tribometers) produce small misalignments between the transduc...

We develop a model to study the locomotion of snakes on inclined planes. We determine numerically which snake motions are optimal for two retrograde traveling-wave body shapes, triangular and sinusoidal waves, across a wide range of frictional parameters and incline angles. In the regime of large transverse friction coefficients, we find power-law scalings for the optimal wave amplitudes and co...

It is often difficult to measure all necessary parameters directly in the current stability control systems. This paper presents a nonlinear observer to estimate vehicle’s yaw rate, lateral acceleration, tire side slip angles and the road friction coefficient based on the measurement signals of the Electric Power Steering (EPS) system and the Anti-lock Braking System (ABS). The performances of ...

Nu-6(1) zeolite, the lamellar precursor of NSI topology, was firstly synthesized with 4'4-bipyridine as the structure-directing agent (SDA) and then subjected to HCl-EtOH treatment for the purpose of structural modification. Interlayer deconstruction and reconstruction took place alternately in this acid treatment. An intermediate named ECNU-4 was separated at the initial stage of this continuo...