The friction of surfaces moving relative to each other must derive from the atomic interaction at interfaces. However, recent experiments bring into question the fundamental understanding of this phenomenon. The analytic theories predict that most perfect clean incommensurate interfaces would produce no static friction, whereas commensurate aligned surfaces would have very high friction. In con...

In this Study, surface of medium carbon steel (AISI 1045) was modified by titanizing followed by plasma nitriding. Titanizing was performed using pack cementation method, in a pack mixture of ferrotitanium, ammonium chloride and alumina, at 1223 K for 45 and 180 min.  Plasma-nitriding was conducted at two temperatures of 803 and 823 K for 5 h, in a gas mixture of 75%N2+25%H2. The samples were c...

In this paper, we present experimental investigation of convective heat transfer characteristic in the inner tube fluid of miniature concentric double tube Hair-pin heat exchanger with constant heat flux. This work is carried out for distilled water and a mixture of distilled water and ethylene glycol (10%, 20% and 25% by volume) as heat transfer cold fluid flowing in inner tube to carry away h...

We have studied friction and dissipation in single and bilayer graphene films grown epitaxially on SiC. The friction on SiC is greatly reduced by a single layer of graphene and reduced by another factor of 2 on bilayer graphene. The friction contrast between single and bilayer graphene arises from a dramatic difference in electron-phonon coupling, which we discovered by means of angle-resolved ...

Recently, by analyzing the measurement data of Nikuradze [NACA Tech. Memo No. 1292 (1950)], it has been proposed [N. Goldenfeld, Phys. Rev. Lett. 96, 044503 (2006)] that the friction factor, f , of rough-pipe flow obeys a scaling law in the turbulent regime. Here, we provide a phenomenological scaling argument to explain this law and demonstrate how intermittency modifies the scaling form, ther...

Even though there exist lots of documents on Finite Element Strength Reduction Method, cohesion and internal friction angle in these materials are reduced through the same reduction factor, which fails to reflect either of their safe reserving quality or the quality to precisely match slope failure process and mechanism. As is known, the exterior angle circumcircle yield criterion DP1 of the ge...

attempts have been made for the first time to produce a friction material with thermal sensitive modulus by the inclusion of combined plastic/rubber properties of thermoplastic elastomers (tpe) as viscoelastic polymeric materials into the formulation for the purpose of increasing the damping behavior. in order to evaluate the viscoelastic parameters such as loss factor (tan δ) and elastic modul...

The average bed shear stress and bed friction factor of samples with any roughness was derived from the head loss between upstream and downstream of a test section in an erosion tunnel. The method was validated in both hydraulically smooth (plexiglass; Reynolds number less than 25,000) and rough regimes (calibrated particles with known roughness). As a first step toward using this method on nat...

The shear strength of the soil is a crucial factor in structure's failure. Before any engineering structure built on soil, characteristics must be thoroughly examined order to reduce calamity structural collapse. current study investigates influence varied percentages fine material strength. sample consists primarily sandy and clay soil. looked into impact fines metrics (friction angle cohesion...