Studies on Optimum Distribution of Fins in Heat Sinks Filled With Phase Change Materials

This paper deals with phase change material (PCM), used in conjunction with thermal conductivity enhancer (TCE), as a means of thermal management of electronic systems. Eicosane is used as PCM, while aluminium pin or plate fins are used as TCE. The test section considered in all cases is a 42×42mm2 base with a TCE height of 25mm. An electrical heater at the heat sink base is used to simulate the heat generation in electronic chips. Various volumetric fractions of TCE in the conglomerate of PCM and TCE are considered. The case with 8% TCE volume fraction was found to have the best thermal performance. With this volume fraction of TCE, the effects of fin dimension and fin shape are also investigated. It is found that a large number of small cross-sectional area fins is preferable. A numerical model is also developed to enable an interpretation of experimental results.

Carpal Tunnel Syndrome in Radial Dysplasia

We treated three patients for carpal tunnel syndrome which developed more than 10 years after reconstructive surgery for radial dysplasia. All responded to decompressive surgery. The radial carpal bones were hypoplastic in all cases, and in two we measured the carpal tunnel with computed tomography (CT). This showed that the anteroposterior diameter and cross-sectional area of the carpal tunnel were small because of the hypoplasia of the carpal bones. We believe carpal tunnel syndrome occurs with radial dysplasia because of the narrow anteroposterior diameter and small cross-sectional area of the carpal tunnel.

Enhancing Small-Channel Convective Boiling Performance Using a Microporous Surface Coating

Performance characteristics are experimentally determined for enhanced convective boiling of FC-87 in a horizontal, small-cross-sectional-area, single-channel heater. The channel tested has a square cross section with a side length of 2 mm and a heated length of 8 cm. The heated surface of the channel is tested both with, and without, a microporous surface coating. Although few studies have been performed to quantify the effects of internal porous coatings on flow boiling, their application in this area is promising. The coating is shown to provide increases in both heat transfer coefficient and critical heat flux. Convective boiling curves are generated for mass fluxes from 500 to 5000 kg/m2s and for inlet subcooling levels ranging from 2 to 31°C.

An investigation into the causes of small scale variation in sediment community oxygen consumption in the Rockall Trough

An attempt was made to interpret the core to core variation in oxygen uptake observed during anin situdetermination of sediment community oxygen consumption (SCOC) at a station in the Rockall Trough using the “suspended core” technique. No direct relationships between macrofaunal abundance or biomass and SCOC were observed. The results obtained suggested that the use of experimental chambers of small cross-sectional area (26.2cm2) allow for greater influence on SCOC of the activity of individual organisms which would otherwise be averaged out by larger, grab-type enclosures. The possible significance of other components of the benthos is discussed.