some physical properties such as geometrical, gravimetrical, frictional and aerodynamic features of seeds of desi chickpea and its splits were studied at a moisture content of 8.2 and 9.0% w., respectively from north-western of iran. geometrical and gravimetrical properties including the average length, width, thickness, the geometric mean of diameter, sphericity, 1000-seed weight, unit weight,...

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 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...

OBJECTIVE To test the frictional resistance forces (FRS) generated between several archwires and (1) interactive self-ligating (ISL) brackets and (2) conventionally ligated (CL) brackets. MATERIALS AND METHODS Frictional forces produced between three different archwire combinations and self-ligating (SL) brackets (ceramic and metal-slot or all-metal) and CL brackets (metal or ceramic) were ev...

In this paper we define a class of mechanical systems consisting of rigid objects (defined by linear or quadratic surface patches) connected by frictional contact linkages between surfaces. (This class of mechanisms is similar to the Analytical Engine developed by Babbage in 1800s except that we assume frictional surfaces instead of toothed gears.) We prove that a universal Turing Machine (TM) ...