The classical problem of rebound is usually treated by assuming that the colliding bodies are rigid and that the coefficient of friction, ~ , is constant. Two contact states can be distinguished: slidinq, in which the ratio of friction force to normal force is equal to ~ , and rolling, in which the friction force is zero. If sliding gives way to rolling during impact, the friction force will fa...

in this paper, surface roughness of ht29 cancerous is determined using topography images obtained by atimic force microscopy (afm). the mean radiuses of cell and substrate surface asperities are determined, based on results of conducted roughness analysis and rabinovich roughness theory. these values have been applied in the equations of rough particle nanomanipulation dynamic model and the amo...

One of the most popular forming processes is the shape rolling process in which the desired shape change is achieved by pressing two rollers with a special shape in the opposite rotational direction. In order to improve the product’s quality and reduce production costs, accurate analysis of the shape rolling process of the compressor blades as well as the investigation of the effective paramete...

Flow-enhanced cell adhesion is an unexplained phenomenon that might result from a transport-dependent increase in on-rates or a force-dependent decrease in off-rates of adhesive bonds. L-selectin requires a threshold shear to support leukocyte rolling on P-selectin glycoprotein ligand-1 (PSGL-1) and other vascular ligands. Low forces decrease L-selectin-PSGL-1 off-rates (catch bonds), whereas h...

In this paper, an analytical method based on Modified Slab Method of analysis is presented to study the asymmetrical rolling process due to difference in work rolls radii, rolls speeds and interface frictions. The shear force imposed on material along the contact region is considered to be a function of the frictional factor and the roll gap geometry. Elastic-plastic with linear work hardening ...

Many experiments have measured the effect of force on the dissociation of single selectin bonds, but it is not yet clear how the force dependence of molecular dissociation can influence the rolling of cells expressing selectin molecules. Recent experiments using constant-force atomic force microscopy or high-resolution microscopic observations of pause-time distributions of cells in a flow cham...

Investigation of vertical vibrations of a railway turnout is important in designing track components under moving loads of trains. In this paper, the turnout is simulated by a linear finite element model with modal damping. A section of the turnout has a length of 36 sleeper spans surrounding the crossing. Rails and sleepers are modeled with uniform Rayleigh-&#10Timoshenko beam elements. The ra...

In order to optimize the continuous rolling schedule for improving the quality of rolled tube billet, three dimensional thermal mechanical coupled finite element simulation is applied to analyse the multi-pass continuous rolling process of Ф100mm 37Mn5 steel tube billet from 200mm×200mm square cast bloom. Due to the larger plastic strain occurring at the corner area of the billet, the bias mesh...

Power Assist Wheelchair (PAW) has being developed for users and caregivers in current high aging society. As a human-machine system, it is important for PAW to sense the human force and operation. In this paper, a Disturbance Observer (DOB) based force estimator is applied to PAW to estimate external forces including the human force, the rolling resistance and the sliding resistance. The rollin...