A suspension of particles below 100 nm in size, usually termed as nanofluid, often shows a notable enhancement in thermal conductivity, when measured by the transient hot-wire method. In contrast, when the conductivity of the same nanofluid is measured by the laser flash method, the enhancement reported is about one order of magnitude lower. This difference has been quantitatively resolved for ...

An exact analytical expression for the effective diffusion coefficient of an overdamped Brownian particle in a tilted periodic potential is derived for arbitrary potentials and arbitrary strengths of the thermal noise. Near the critical tilt (threshold of deterministic running solutions) a scaling behavior for weak thermal noise is revealed and various universality classes are identified. In co...

an experimental and theoretical energy and exergy analysis was conducted for a cylindrical cavity receiver employed in a parabolic dish collector. based on simultaneous energy and exergy analysis, the receiver average wall temperature and overall heat transfer coefficient were determined. a simplified nusselt number for heat transfer fluid (htf) through the receiver as a function of reynolds an...

graphene oxide was prepared using modified hummers method. stable ethylene-glycol nanofluids containing graphene oxide nanosheets were provided. nd: yag pulsed laser was applied to prepare reduced nanofluids. experimental results revealed that thermal conductivity of the nanofluids is increased with increasing the concentration of graphene oxide (go) in ethylene glycol. the enhancement ratio of...

An approach based on design of different experiments for improvement the thermal paths in PCB through thermal vias is offered. An efficient thermal via placed on the PCB decreases the junction temperature of the package. In this paper elaborate study has been done in analyzing the effect of thermal vias and the ways to decrease the junction temperature by given number of computations. Thermal e...

The thermal conductivity of boron nitride/ethylene glycol (BN/EG) nanofluids was investigated by transient hot-wire method and two abnormal phenomena was reported. One is the abnormal higher thermal conductivity enhancement for BN/EG nanofluids at very low-volume fraction of particles, and the other is the thermal conductivity enhancement of BN/EG nanofluids synthesized with large BN nanopartic...

In the present work, we report measurements of the effective thermal conductivity of dispersions of single-walled carbon nanotube (SWNT) suspensions in ethylene glycol. The SWNTs were synthesized using the alcohol catalytic chemical vapour deposition method. Resonant Raman spectroscopy was employed to estimate the diameter distribution of the SWNTs based on the frequencies of the radial breathi...