Background: A rippled type of pigmentation is observed on the arms, forearms, and bony prominences, more commonly in women with a history of chronic rubbing. The terminology (commonly referred to as frictional melanosis) and its relation with cutaneous amyloidosis has been debated. Materials and Methods: Twenty one patients with pigmented skin lesions with manifestations suggestive of frictiona...

The scheme for accurate and reliable predictions of tunnel stability based on an artificial aeural network (ANN) is presented in this study. Plastic solutions the unlined elliptical tunnels sands are first derived by using numerical upper-bound (UB) lower-bound (LB) finite element limit analysis (FELA). These later used as training dataset ANN model. Note that there four input dimensionless par...

Analyzing the landslide situation is one of urgent scientific and practical problems in determining conditions for carrying out construction works protecting human life economic sectors from danger. Landslides can cause damage, disable large structures roads, destroy areas crops, villages cities. In this study, Akhangaran reservoir lands, techniques assessing slope stability, ground mass stabil...

The evolutionary history of vertebrate locomotion is punctuated by innovations that have permitted expansion into novel ecological niches. Frictional adhesion of geckos is an innovation renowned for enabling locomotion on vertical and inverted smooth surfaces. Much is known about the microstructure and function of the fullyexpressed gekkotan adhesive apparatus, although how it originated is poo...

We present two geometric descriptions of the frictional properties of a rigid body sliding on a planar surface. The limit surface LS, from classical plasticity theory, is the boundary of the set of all possible frictional forces and moments that can be sustained by the frictional interface. Zhukovskii’s moment finction is the frictional moment as a function of the instantaneous center of rotati...

The transition from frictional to lubricated flows of a dense suspension of non-Brownian particles is studied. The pertinent parameter characterizing this transition is the Leighton number Le=eta(s)gamma / sigma, the ratio of lubrication to frictional forces. Le defines a critical shear rate below which no steady flow without localization exists. In the frictional regime the shear flow is local...

Antimony nanoparticles deposited under UHV conditions on HOPG are found to exhibit an intriguing frictional behavior characterized by a distinct clearly separated double dual behavior of dependence of the frictional force on contact area. We present the first realistic simulations, density functional modeling adapted to accommodate van der Waals interactions, of the (double) dual frictional beh...

With the advancement of the field of biotribology, considerable interest has arisen in the study of cell and tissue frictional properties. From the perspective of medical device development, the frictional properties between a rigid surface and underlying cells and tissues are of a particular clinical interest. As with many bearing surfaces, it is likely that contact asperities exist at the siz...