Critical heat flux (CHF) was measured for a water-cooled micro-channel heat sink containing 21 parallel 215· 821 lm channels. Tests were performed with deionized water over a mass velocity range of 86–368 kg/ms, inlet temperatures of 30 and 60 C, at an outlet pressure of 1.13 bar. As CHF was approached, flow instabilities induced vapor backflow into the heat sink’s upstream plenum, which signif...

Fluid transport is accomplished in a micro throttle pump (MTP) by alternating deformation of a micro channel cast into a PDMS elastomeric substrate. The active deformation is achieved using a bimorph PZT piezoelectric disk actuator bonded to a glass diaphragm. The bimorph PZT deflects the diaphragm as well as alternately pushing and pulling the elastomer layer providing displacement amplificati...

Abstract There is great interest in the development of micromotors which can convert energy to motion sub-millimeter dimensions. Micromachines take micromotor concept a step further, comprising complex systems multiple components work concert effectively realize mechanical tasks. Here we introduce light-driven and micromachines that rely on optoelectronic tweezers (OET). Using circular micro-ge...

in this paper, a novel directional super wide band micro strip antenna based on a simple and new geometry has been proposed. the antenna exhibits the widest bandwidth ever reported to the authors’ knowledge from 50 ghz to 200 ghz. its radiation pattern is approximately steady in the frequency ranges of 50 ghz to 200 ghz. the antenna consists of a club-like radiating patch, a combination of thre...

Ideally, the design of high-performance micro-hotplates would require a large number of simulations because of the existence of many important design parameters as well as the possibly crucial effects of both spread and drift. However, the computational cost of FEM simulations, which are the only available tool for accurately predicting the temperature in micro-hotplates, is very high. As a res...

In this paper, using theory of sheets, the deflection of suspended diaphragm has been obtained under uniform and circular loading. This type of diaphragm, unlike other diaphragms, has a central support which is recommended to be used in MEMS applications. The relationship between diaphragm deflection and static analysis of this diaphragm enjoys a great significance in investigating and understa...

This is t~e fifth of several compilations of briefing papers on w~ter quahty prepared by the U.S. Geological Survey. Each bne:fing paper is prepared in a simple, nontechnical, easy-tounderstand manner. This U.S. Geological Survey Circular contains three papers on the microbiology of aquatic environment. Briefing papers are included on "The ecological role(s) of aquatic micro-organisms in lakes ...

Abstract: The flow generated by a circular cylinder, performing longitudinal and torsional oscillations, in an infinite expanse of a micropolar fluid is studied under the influence of uniform transverse magnetic field. Analytical expressions for the velocity components and micro rotation components are obtained by using no slip and hyper stick conditions on the boundary of the cylinder. The eff...