The first phase of a project at Sunpower, Inc. sponsored by the EPA is described. The program involves the design, computer simulation and fabrication of a high efficiency linear compressor for application in domestic refrigeration. The use of a high efficiency electric motor and non-contact operation can dramatically reduce the electrical and friction losses associated with crank compressors. ...

Drug delivery through jet-injection opens the doors to very rapid drug dispersion by eliminating the need for needle sterilization. With this comes the need for a continuous flow of fluids from a large reservoir, currently not available to the single-piston drug delivery systems. A two-piston system in a jet injector enables the use of a cyclic motion of pistons to drive the injected fluids, as...

By theoretically analyzing dynamic behavior of the crankshaft, the rolling piston and the blade inrolling-piston rotary compressors, constraint forces and sliding speed at each pair of movable machine elements were obtained, and unbalanced inertia forces and compressor vibrations were evaluated. It was concluded that theoretical results have a goodagreement with experimental ones. Moreover, it ...

We consider the motion of a test particle in a one-dimensional system of equal-mass point particles. The test particle plays the role of a microscopic "piston" that separates two hard-point gases with different concentrations and arbitrary initial velocity distributions. In the homogeneous case when the gases on either side of the piston are in the same macroscopic state, we compute and analyze...

OBJECTIVE This study aimed to compare gas exchange with heliox and oxygen-enriched air during piston-type high-frequency oscillatory ventilation (HFOV). We hypothesized that helium gas would improve both carbon dioxide elimination and arterial oxygenation during piston-type HFOV. METHOD Five rabbits were prepared and ventilated by piston-type HFOV with carrier 50% helium/oxygen (heliox50) or ...

In this work, a generalized expression of the photoacoustic ~PA! effect in a multilayer material is derived. This expression takes thermal and optical properties and geometry of a multilayer structure, as well as the thermal contact resistances between layers into consideration. In addition, a composite piston model consisting of a thermal piston and a mechanical piston of the PA effect is deve...

Due to their high relative cost, solar-electric energy systems have yet to be exploited on a widespread basis. It is believed in the energy community that a technology similar to photovoltaics, but offered at about $1/W, would lead to widespread deployment at residential and commercial sites. This paper addresses the feasibility study of a low-cost solar-thermal electricity generation technolog...

This paper describes a system for measuring the temporal parameters of hemiplegic gait. This system uses shoe insoles with sensors, acting as switches, placed under the heel, head of the first metatarsal, head of the fifth metatarsal and the big toe. This system is able to monitor gait for up to 10 min and can be used by the patient over any surface. Parameters for evaluating hemiplegic gait ar...

Abstract The thermal shock of subsurface material with shear instability and severe plastic flow during scuffing was investigated. damage M50 steel tested using a high-speed rolling—sliding contact test rig, the transient temperature calculated Fourier transform method considering effects both frictional heat work. results show that rapid rise subsequent decrease in is generated layers. power i...

Free-piston engines are under investigation by a number of research groups worldwide, as an alternative to conventional technology in applications such as electric and hydraulic power generation. The piston dynamics of the freepiston engine differ significantly from those of conventional engines, and this may influence in-cylinder gas motion, combustion and emissions formation. Due to the compl...