The first product in the Newton family operates under severe constraints in the areas of performance, cost, heat dissipation, power consumption, scalability, size and weight. This talk gives an overview of the Newton MessagePad system hardware, and focuses on the techniques and tradeoffs used to overcome these constraints. In particular, synergetic migration of functions from hardware to softwa...

The power dissipation levels in high performance personal computers continue to increase rapidly while the silicon die temperature requirements remain unchanged or have been lowered. Advanced air cooling solutions for the major heat sources such as CPU and GPU modules use heat pipes and high flow rate fans to manage the heat load at the expense of significant increases in the sound power emitte...

Graphene, which exhibits excellent thermal conductivity, is a potential heat dissipation medium for compact optoelectronic devices. Photonic devices normally produce large- quantity of unwanted heat, and thus, a heat dissipation strategy is urgently needed. In this study, single-layer graphene (SLG) grown by chemical vapor deposition (CVD) is used to cover the surface of a photonic crystal (PhC...

PURPOSE A multi-turn transmit surface coil design was presented to improve B1 efficiency when used with current source amplification. METHODS Three different coil designs driven by an on-coil current-mode class-D amplifier with current envelope feedback were tested on the benchtop and through imaging in a 1.5 T scanner. Case temperature of the power field-effect transistor at the amplifier ou...

ARTICLE INFO Cooling of electronics component is one of the major challenges faced by thermal engineers. In recent years, a significant increase in microprocessor power dissipation coupled with CPU size has resulted in an increase in heat fluxes. Microprocessor heat fluxes have also increased for many commercial applications. Therefore, thermal management is becoming one of most challenging iss...

To meet the higher accuracy, stiffness and speed demands of positioning systems of machine tools and measuring instruments, two motor concepts are developed with an integrated bearing-driving functionality. For both concepts, piezoelectric technology is used as actuator principle. In the first concept, the limited stroke of piezoactuators is overcome by a travelling-wave principle, which assure...

Electrothermal energy storage (ETES) provides bulk electricity storage based on heat pump and heat engine technologies. A subcritical ETES is described in this paper. Based on the extremum principle of entransy dissipation, a geometry model is developed for heat transfer optimization for subcritical ETES. The exergy during the heat transfer process is deduced in terms of entropy production. The...

It is noted that the results of recent experiments on the enhancement of turbulent kinetic energy (TKE) dissipation below surface waves can be stated as follows. TKE dissipation is enhanced by a factor 15Hws/z at depths 0.5Hws < z < 20Hws with respect to the wall-layer result ǫ = u ∗w/κz, where u∗w is the friction velocity in water and Hws is the significant windsea wave height. For open ocean ...

The incidence of heat-related illness in the workplace is linked to whether or not workers have acclimated to a hot environment. Heat acclimation improves endurance work performance in the heat and thermal comfort at a given work rate. These improvements are achieved by increased sweating and skin blood flow responses, better fluid balance and cardiovascular stability. As a practical means of a...

Pool boiling enhancement through surface modification has garnered the attention of many researchers for extending the limits of heat flux dissipation. Simulated copper chips were used in a pool boiling setup with water boiling at atmospheric pressure. Heat transfer performance of different microchanneled surfaces was compared to that of a plain surface. The results of the study showed that the...