Carbon nanotubes (CNTs) are well known for their exceptional thermal, mechanical and electrical properties. For many CNT applications it is of the foremost importance to know their frictional properties. However, very little is known about the frictional forces between an individual nanotube and a substrate or tip. Here, we present a combined theoretical and experimental study of the frictional...

Friction limits the operation of macroscopic engines and is critical to the performance of micromechanical devices. We report measurements of friction in a biological nanomachine. Using optical tweezers, we characterized the frictional drag force of individual kinesin-8 motor proteins interacting with their microtubule tracks. At low speeds and with no energy source, the frictional drag was rel...

The magneto-frictional method is used in solar physics to compute both static and quasi-static models of the Sun's coronal magnetic field. Here, we examine how accurately magneto-friction (without fluid pressure) able predict relaxed state a one-dimensional test case containing two null points. Firstly, show that relaxation under full ideal magnetohydrodynamic equations presence nulls leads nec...

Pressure differences across topography generate a form drag that opposes the flow in the water column, and viscous and pressure forces acting on roughness elements of the topographic surface generate a frictional drag on the bottom. Form drag and bottom roughness lengths were estimated over the East Flower Garden Bank (EFGB) in the Gulf of Mexico by combining an array of bottom pressure measure...

Liquid-solid phase transition and the change of the frictional force of a system with two hard spheres in a two-dimensional rectangular box are discussed. Under controlling the pressure or the supply of energy from the wall, the solid like state, the solid-liquid temporal coexistence state, and the liquid like state are alternatively observed. The frictional force which works on particles and t...

Understanding friction and wear of biomaterials when in contact with articular cartilage is vital within the development of future hemi-arthroplasty and cartilage substitution. This study aimed to compare the frictional properties of single phase and biphasic polymeric materials against articular cartilage. Continuous sliding friction was applied by means of a simple geometry wear simulator. Th...

compressible gas flow inside a convergent-divergent nozzle and its exhaust plume atdifferent nozzle pressure ratios (npr) have been numerically studied with severalturbulence models. the numerical results reveal that, the sst k–ω model give the bestresults compared with other models in time and accuracy. the effect of changes in value ofdivergence half-angle (ε ) on the nozzle performance, thru...

Indentation hardness has been used extensively for material characterization and many recent computational studies have established quantitative relationships between elasto-plastic mechanical properties and the response in instrumented indentation. In contrast, very few studies have systematically quantified the effect of the plastic deformation characteristics on the frictional sliding respon...

The purpose of the study was to measure and compare the level of frictional resistance generated between conventional ceramic brackets (Transcend Series 6000, 3M Unitek, Monrovia, Calif), ceramic brackets with stainless steel slot (Clarity, 3M Unitek), conventional stainless steel brackets (Victory Series, 3M Unitek), and 3 different orthodontic wire alloys: stainless steel (stainless steel, SD...