Recent progress on a Stirling engine driven hea t pump is described and a modeling technique for predicting engine dynamics is developed. The system described represents a very p romising configuration of engine driven heat pump, because o f the long life characteristics of the free-piston Stirling engin e and the hermetic nature of both the engine and refrigerant work ing fluids. Recent change...

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 literature on Foreign Direct Investment (FDI) has recently analyzed the nature of the firm’s entry mode choice in a foreign market, particularly the choice between a joint venture and a wholly owned subsidiary. Foreign-based companies are defined as having one or more overseas manufacturing subsidiaries or joint venture relationship. Foreign-based companies can be divided into following thr...

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 ...