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To operate under normal conditions and depending on the technology used, the electronic components must be at a temperature below 80 to 85 degrees C. Several cooling systems were investigated with the aim of improving the heat transfer process in this kind of applications. Single-phase liquid cooling systems, which mainly consist of a hot watercooled micro-heat exchanger, provide an efficient approach to dissipate heat flows. In the present study, numerical and experimental investigations were carried out to study the characteristics of laminar flow and forced convective heat transfer in micro-channels. The inlet temperature of cooling water ranged from 25 to 65 degrees C, the Reynolds number of water flow varied from 250 to 2000, and the electronic power supply component was set at 50, 80 and 120 W. The results showed that the micro heat exchanger was able to dissipate around 70 to 78% of the heat released by the electronic component. As regards the numerical results, it was observed that the inlet water temperature of 55 degrees C kept a heat source up to 80 W for a temperature source below the critical value of 80 degrees C.

Ultrasonic radiation forces can be used for non-intrusive manipulation and concentration of suspended micrometer-sized particles. For bioanalytical purposes, standing-wave ultrasound has long been used for rapid immuno-agglutination of functionalized latex beads. More recently, detection methods based on laser-scanning fluorometry and single-step homogeneous bead-based assays show promise for fast, easy and sensitive biochemical analysis. If such methods are combined with ultrasonic enhancement, detection limits in the femtomolar region are feasible. In this paper, we review the development of standing-wave ultrasonic manipulation for bioanalysis, with special emphasis on miniaturization and ultrasensitive bead-based immunoassays., QC 20100525