It is generally assumed that fingerprints improve the grip of primates, but the efficiency of their ridging will depend on the type of frictional behaviour the skin exhibits. Ridges would be effective at increasing friction for hard materials, but in a rubbery material they would reduce friction because they would reduce contact area. In this study we investigated the frictional performance of ...

We demonstrate measurement and control of single-asperity friction by using cantilever probes featuring an in situ solid-state heater. The heater temperature was varied between 25 and 650 °C (tip temperatures from 25 ± 2 to 120 ± 20 °C). Heating caused friction to increase by a factor of 4 in air at ∼ 30% relative humidity, but in dry nitrogen friction decreased by ∼ 40%. Higher velocity reduce...

INTRODUCTION Fixed orthodontic appliances have been regarded as a common causative factor of oral lesions. To manage soft tissue discomfort, most orthodontists recommend using a small amount of utility wax over the brackets in order to alleviate trauma. This in vitro study aimed at evaluating friction generated by two types of bracket protectors (customized acetate protector [CAP] and temporary...

Knowledge of the tribology of human skin is essential to improve and optimize surfaces and materials in contact with the skin. Besides that, friction between the human skin and textiles is a critical factor in the formation of skin injuries, which are caused if the loads and shear forces are high enough and/or over long periods of time. This factor is of particular importance in bedridden patie...

in this research, the effect of friction between the liquid metal and the sand mould wall and the effect of passage of liquid through a vertical bend and through a ceramic filter on the fluid flow and the melt velocity has been studied by measuring the velocity of the melt and direct observation of the liquid flow through the different parts of a naturally-pressurized running system. the fricti...

This paper investigates the friction coefficient of a moving liquid marble, a small liquid droplet coated with hydrophobic powder and floating on another liquid surface. A floating marble can easily move across water surface due to the low friction, allowing for the transport of aqueous solutions with minimal energy input. However, the motion of a floating marble has yet to be systematically ch...

in the present study, turbulent flow in channels of a plate heat exchanger with corrugated chevron plates has been simulated numerically using the commercial cfd package, fluent. unstructured mesh is used for discretizing the computational domain and simple algorithm is utilized to solve the pressure and velocity equations. there is a wide selection of different plate heat exchangers within the...

reliability analysis of rock slope stability has received considerable attention in the literature. it has been used as an effective tool to evaluate uncertainty so prevalent in variables. in this research the application of the jointly distributed random variables method for probabilistic analysis and reliability assessment of rock slope stability with plane sliding is investigated. in a recen...

introduction increasing the area of absorber plate between the flowed air through the duct can be accomplished by corrugating the absorber plate or by using the artificial roughness underside of the absorber plate as the commercial methods for enhancing the thermohydraulic performance of the flat plate solar air heaters. evaluation of this requires the construction of separated solar air heater...

The present work is carried out to investigate heat transfer and friction factor characteristics of fluid (air) flow through turbulent channel i.e. parallel plate heat exchanger for different geometry and designs parameters, with a bottom plate applied to uniform constant heat flux thermal boundary condition, and upper plate is provided with a insulated condition. The fluid domain is designed u...