Abstract: materials can be fabricated by sintering of W-Cu composite powders. In this research W-20%wt Cu composite powderswas synthesized via a co-precipitation method. Precipitate obtained from a mixture of copper nitrate and ammoniumparatungstate (APT) in distilled water contained W-Cu compounds. This precipitate was washed, dried and calcinedat 550 of dried precipitate powder was determined...

Article history: Received 23 December 2009 Received in revised form 10 June 2010 Accepted 10 June 2010 Available online 16 July 2010

In this study, the three-dimensional fluid flow and heat transfer in a rectangular micro-channel heat sink are analyzed numerically using water as the cooling fluid. The heat sink consists of a 1-cm silicon wafer. The micro-channels have a width of 57 lm and a depth of 180 lm, and are separated by a 43 lm wall. A numerical code based on the finite difference method and the SIMPLE algorithm is d...

Christopher L. Chapman, and Seri Lee Aavid Engineering, Inc. Laconia, New Hampshire 03247 Bill L. Schmidt Silicon Graphics Computer Systems Mountainview, California 94039 Comparative thermal tests have been carried out using aluminum heat sinks made with extruded fin, cross-cut rectangular pins, and elliptical shaped pins in low air flow environments. The elliptical pin heat sink was designed t...

Three dimensional heat transfer and water flow characteristic in a set of rectangular microchannel heat sinks for advanced electronic systems investigated in this paper. The full Navier-Stoke’s approach is employed for this kind of narrow channels for the water flow assessments. The complete form of the energy equation accompanying the dissipation terms is also linked to the momentum equations....

Water-deficit stresses preferentially reduce shoot growth, thereby disrupting the flow of carbohydrates from source leaves to the developing sinks. Here, we use a novel stress bioassay to dissect responses of field and greenhouse-grown cotton (Gossypium hirsutum) source leaves to water-deficit stresses. Fifth main stem leaf samples were harvested at sunrise and subjected to a prolonged elevated...

Many of the more recent applications of PowerMOS transistors, particularly low voltage devices, have been as solenoid drivers. In this type of application the device is simply used as a switch to turn the current through a solenoid, relay or other inductive load on and off (Figure 1). Since the dissipation is low, a very small or no heat sink will be required. This note will cover the applicati...

The Study of heat transfer augmentation in micro scale and electronic packaging systems are some of the paramount areas of the impending universe. In such systems the cooling of the heat sinks are generally achieved through the impingement of air jet. Assuming the air jet to be continues & incompressible fluid, the heat dissipation rate over the target surface seems to either uniform or well ch...

Here we show that hierarchical structures based on one-dimensional filaments such as carbon nanotubes lead to superior thermal management networks, capable of effectively mitigating high-density ultrasmall nanoscale heat sources through volumetric heat sinks at micrometer and larger scales. The figure of merit of heat transfer is quantified through the effective thermal conductance as well as t...

As the temperature of electronic devices increases, their failure rate increases. That is why electrical devices should be cooled. One of the promising cooling techniques is using Phase Change Materials (PCMs). A new passive temperature management technique, that involves the direct placement of PCMs on the chip, has been explored and developed. PCMs are potential temperature regulators that ca...