the objective of this research work is to evaluate the surface roughness of polyacrylonitrile (pan) nanowebs. for this purpose the nanowebs have been prepared in different concentrations of pan solution from 11 to 15% (by wt). surface roughness of nanowebs was evaluated by entropy algorithm (ent) as well as atomic force microscopy (afm) and then the results of two methods have been compared. to...

When a finger scans a non-smooth surface, a sensation of roughness is experienced. A similar sensation is felt when a finger is in contact with a mobile surface vibrating in the tangential direction. Since an actual finger-surface interaction results in a varying friction force, how can a measured friction force can be converted into skin relative displacement. With a bidirectional apparatus th...

This study investigated the effect of hydrogel surface roughness on its sliding friction against a solid substrate having modestly adhesive interaction with hydrogels under small normal pressure in water. The friction test was performed between bulk polyacrylamide hydrogels of varied surface roughness and a smooth glass substrate by using a strain-controlled rheometer with parallel-plates geome...

The present paper investigates experimentally the effect of relative humidity and roughness on friction property of mild steel under horizontal vibration. To do so, a pin-on-disc apparatus having facility of vibrating the test samples at different direction is designed and fabricated. The direction of vibration is horizontal. Horizontal vibration is created along (longitudinal direction) and pe...

The present study investigated the role of alloy microstructure and surface roughness on wear and friction behavior of leaded and unleaded tin bronzes. Ball-on-disk experiments were carried out under dry conditions with steel balls sliding against bronze disks. Scanning electron microscopy (SEM), energy dispersive electron microscopy (EDX), x-ray photoelectron spectroscopy (XPS) and Auger elect...

A detailed model of the role of asperities in crack closure has been initiated in Part 1 of this article. Crack opening stress is defined as the far-field stress required to overcome the asperity-induced contact stresses along the crack. In this Part 2, the magnitude of crack opening stress is established as a function of roughness (s0); asperity density (N); maximum stress level (Smax/Sy); sha...

Ultra high molecular weight polyethylene (UHMWPE) submicron wear debris particles in total joint replacement (TJR) prosthesis have been observed clinically to cause osteolysis. In this study, the formation of UHMWPE submicron wear debris was investigated by modeling a nanoscale asperity on the surface of a CoCr femoral component of a total knee replacement (TKR) prosthesis using a Si3N4 AFM com...

In the present study, plate impact pressure±shear friction experiments are conducted to provide insight into timeresolved dry sliding characteristics of metal on metal at normal pressures of approximately 1.5 GPa, slip speeds up to 60 m/s and interfacial temperatures as high as 8008C. The plate impact friction experiments represent a signi®cant improvement over conventional dynamic friction exp...

Friction characteristics with respect to surface topographic orientation were investigated using surfaces of different materials and fabricated with grooves of different scales. Scratching friction tests were conducted using a nano-indentation-scratching system with the tip motion parallel or perpendicular to the groove orientation. Similar friction anisotropy trends were observed for all the s...

Lateral Force Microscopy (LFM) studies were carried out on cleaved calcite sections in contact with solutions supersaturated with respect to otavite (CdCO3) or calcite-otavite solid solutions (SS) as a means to examine the potential for future application of LFM as a nanometer-scale mineral surface composition mapping technique. Layer-by-layer growth of surface films took place either by step a...