The bituminous pavement rehabilitation alternatives are mainly overlaying, recycling and reconstruction. In the recycling process the material from deteriorated pavement, known as reclaimed asphalt pavement (RAP), is partially or fully reused in fresh construction. Some of the advantages associated with pavement recycling are (i) less user delay (ii) conservation of energy (iii) preservation of...

This study investigated the relationship between the pinch-off of axisymmetric vortex rings and the evolution of pressure in the shear layer being entrained into the vortex rings. A piston-cylinder apparatus was used to generate the vortex rings, and five cases of constant piston acceleration over distances ranging from zero (impulsive start) to eight piston diameters were investigated. It was ...

The compression chamber of a hermetic reciprocating compressor is, normally, formed by a cylinder and a piston which present a constant clearance during the piston displacement inside the compression chamber. This configuration has the advantage of a good sealing, however, during the most part of compression, the pressure difference between compression chamber and internal compressor ambient is...

In the paper a comprehensive model of a piston ring pack motion on an oil film has been presented. The local oil film thickness can be compared to height of the combined roughness of sliding surfaces of piston rings and cylinder liner. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been c...

The paper presents some typical results regarding the evolution of friction torque during four balls scuffing tests. tests were conducted in 10 seconds running periods having 100 N loading steps, according to ISO 20623:2017. For testing, 12.7 mm bearing manufactured by SKF used and as lubricant, U90Ca3 grease was used. A special device conceived built evaluate between using a force transducer m...

Does it feel the same when you touch an object in Augmented Reality (AR) or in Virtual Reality (VR)? In this paper we study and compare the haptic perception of stiffness of a virtual object in two situations: (1) a purely virtual environment versus (2) a real and augmented environment. We have designed an experimental setup based on a Microsoft HoloLens and a haptic force-feedback device, enab...

With the aim of developing a method for reducing energy consumption of room air conditioners, we address a higher-efficiency design of the rotary compressor currently most used worldwide. We focused on a new rotary compressor equipped with a mechanism to restrict the rolling motion of the piston, and performed a dynamics analysis. The new rotary compressor has a small pillar at the tip of the v...

introduction:different types of prosthesis are available for stapes replacement. because there has been no published report on the efficacy of the titanium soft-clip vs the fluoroplastic causse loop teflon piston, we compared short-term hearing results of both types of prosthesis in patients who underwent stapedotomy due to otosclerosis.materials and methods:a total of 57 ears were included in ...

Abstract The scuffing load carrying capacity is a decisive design criterion in the development of gears. In addition to gear geometry, entire tribological system gearbox must also be taken into account. Besides loads and speeds occuring during operation gears, lubricant used its additives have significant influence on capacity. particular, hypoid gears show an unfavorable combination high slidi...

in this paper a mathematical simulation of a simplified internal combustion engine is presented. to contribute engine kinematics and its geometry, simple relations are derived for constrained motions. the equation of motion for the piston forms a singular boundary value problem. the uniqueness of the solution was studied in the banach space. for solving governing equations an iterative numerica...