Understanding the frictional properties of nanostructured surfaces is important because of their increasing application in modern miniaturized devices. In this work, lateral force microscopy was used to study the frictional properties between an AFM nanotip and surfaces bearing well-defined nanodomes comprising densely packed prolate spheroids, of diameters ranging from tens to hundreds of nano...

One of the most important research field in mechatronics, and particularly in robotics, regards the estimation of the dynamic parameters of a general mechanical system. Many researchers have tried to understand how obtain a good dynamic parameters estimation and what are the best methodologies to apply in order to find them; now some already tested methods are widely available (see, for example...

Friction appears in all mechanical systems and has a significant impact on control. This paper presents simple but effective nonlinear friction compensation method for a drillstring system, by considering the stickslip motion of the bit on the bottom hole assembly (BHA) in oil wells. Due to nonlinear problem at nearzero velocity where the torque exerted on bit is a function of the bit speed, th...

The orders-of-magnitude higher luminosities required by future electron–ion collider concepts require a dissipative force to counteract the numerous factors acting to gradually increase the phase space volume of relativistic ion beams. High-energy electron cooling systems could provide the necessary dissipation via dynamical friction, but will have to be designed for new parameter regimes. It i...

Friction stir processing (FSP) has been developed on the principles of friction stir welding (FSW) as an effective and efficien new method for grain refinement and microstructural modification, providing intense plastic deformation as well as higher strain rates than other conventional severe plastic deformation methods. FSP produces an equiaxed homogeneous microstructure consisting of fine gra...

Ball on disc tribometer and atomic force microscopy (AFM) were used to analyse the effect of base oil polarity on the friction behaviour of steel–steel contacts lubricated with base oilzzinc dialkyldithiophosphate (ZDDP) solutions. Understanding the lubrication properties of the first chemisorbed layer of additives on work pieces yields important information for the optimisation of lubricant fo...

A nonlinear observer for estimation of the longitudinal velocity, lateral velocity, and yaw rate of a vehicle, designed for the purpose of vehicle side-slip estimation, is modified and extended in order to work for different road surface conditions. The observer relies on a road-tire friction model and is therefore sensitive to changes in the adhesion characteristics of the road surface. The fr...

-A pressure-shear plate impact experiment is introduced to study time-resolved friction at interfaces subjected to high sliding speeds under relatively high normal pressures. The conditions of slip at the interface are varied by changing the surface roughness of the impacting plates and by varying the applied normal to shear stress ratio. The configuration offers the simplicity of allowing the ...

This work outlines the etiological factors for exercise-related foot blisters and the pertinent prevention strategies related to these causes. Blisters result from shear forces within the epidermis causing cell necrosis. The extent of skin shear is influenced by friction at the skin and other interfaces, various skin characteristics, bony movement, and the shear modulus of the foot ware. The nu...

An increase in the rates of activated processes with the coupling to the solvent has long been predicted through the phenomenological Langevin equation in the weak coupling regime. However, its direct observation in particle-based models has been elusive because the coupling typically places the processes in the spacial-diffusion limited regime wherein rates decrease with increasing friction. I...