Problem statement: Reflectarrays provide a low cost and low profile solution for antennas required for high gain applications but their use is restricted in some applications due to the narrow bandwidth and high loss performance. These performance limitations can be attributed to different sources of reflectivity of the reflectarrays. This work provides a thorough investigation on the reflectiv...

Matrix technique described in this article combines the advantages of both flexible and rigid matrix in anterior composite restorations. Using mylar strip provide advantages, of one utilizing the mylar strip for contouring the labial aspect of restoration thereby, and overcomes the problem in adapting the teflon tape around the tooth.

A dynamic model of a free liquid piston that exploits piston geometry to produce a high inertance was developed for use in a free piston engine compressor. It is shown that for the size scale targeted, advantageous piston dynamics can be achieved with a reduced piston mass compared to a rigid piston design. It is also shown that the viscous losses associated with the liquid piston are negligibl...

Pressure and performance requirements of axial piston pumps and the proportion of churning losses in axial piston pumps increase significantly with increasing speed. To investigate the primary distribution of churning losses in axial piston pumps at various ranges of speed, a test rig was set up in which other friction losses can be eliminated, thus making it possible to investigate the net chu...

A running-in and starved lubrication experiment is designed to investigate the heavy-duty scuffing behavior of piston ring coatings against cast iron (Fe) cylinder liner using the piston ring reciprocating liner test rig. The scuffing resistance of the piston ring with the chromium-based ceramic composite coating (CKS), and that with the thermally sprayed nickel-chromium-molybdenum coating (NCM...

Although microfluidics has shown exciting potential, its broad applications are significantly limited by drawbacks of the materials used to make them. In this work, we present a convenient strategy for fabricating whole-Teflon microfluidic chips with integrated valves that show outstanding inertness to various chemicals and extreme resistance against all solvents. Compared with other microfluid...

This paper shows the mixed lubrication analysis between the vane tip and rolling piston in a rotary refrigerant compressor, coupling the motion equations of vane and rolling piston, the elastohydrodynamic lubrication (EHL) analysis of line contact and the equations of viscosity characteristics of lubricating oil as a function of oil pressure, oil temperature and concentration of refrigerant. Th...

NAOS (Nasmyth Adaptive Optics System) is the adaptive optics system presently developed for the ESO VLT. The field selectors are to feed the NAOS wavefront sensor with the light coming from an appropriate reference source which can be up to 1 arcmin (on the sky) distant from the center of the field of view. A large input tip-tilt-piston mirror selects the required part of the field of view. A s...