Heat transport across a gold nanowire/water interface enhanced by the solution ionic strength

2015 ◽  
Vol 1779 ◽  
pp. 33-38 ◽  
Author(s):  
Susil Baral ◽  
Andrew J. Green ◽  
Hugh H. Richardson

ABSTRACTLithographically fabricated gold nanowires are optically excited with 532nm CW laser and the local temperature change is measured in air, pure water and various concentration aqueous solutions of ionic solutes NaCl, Na2SO4 and MgSO4 using the thermal sensor film of Al0.94Ga0.06N embedded with Er3+ ions. The interface thermal resistance for heat transfer from the excited nanowires into the surrounding liquid is determined from the slopes of the temperature change versus laser intensity plots obtained for the nanowire excitation under various solutions. Addition of ionic solute molecules into the solution decreases the interface thermal resistance and hence leads to increased heat dissipation into the surrounding liquid. Interface thermal resistance decreases exponentially with the ionic strength of solution and saturates around zero for solution ionic strength of 0.3M and higher.

2021 ◽  
Vol 1035 ◽  
pp. 655-662
Author(s):  
Qian Yu Wang ◽  
Chang Li Cai ◽  
Zhong Shan Deng

At present, the existing thermal interface materials (TIMs) cannot meet the heat dissipation requirements of some high-power density electronic devices. In this study, Bi-based low melting point alloy was made into a thermal conductive sheet to reduce the interface thermal resistance. The thermal conductivity of a thermal conductive sheet was found to be 37.83 W/(m·K), 10 times higher than Dow Corning 5021 thermal grease. In addition, the surface morphology of the Bi-based alloy thermal conductive sheet was changed in this experiment, which was divided into textured and planer type, and the measured interface thermal resistance values lower than Dow Corning 5021 thermal grease by approximately 30% and 27%, respectively. The results prove this Bi-based alloy thermal conductive sheets have the ideal heat dissipation performance and their wide application prospects in high-power density electronic devices.


Author(s):  
Nico Setiawan Effendi ◽  
Kyoung Joon Kim

A computational study is conducted to explore thermal performances of natural convection hybrid fin heat sinks (HF HSs). The proposed HF HSs are a hollow hybrid fin heat sink (HHF HS) and a solid hybrid fin heat sink (SHF HS). Parametric effects such as a fin spacing, an internal channel diameter, a heat dissipation on the performance of HF HSs are investigated by CFD analysis. Study results show that the thermal resistance of the HS increases while the mass-multiplied thermal resistance of the HS decreases associated with the increase of the channel diameter. The results also shows the thermal resistance of the SHF HS is 13% smaller, and the mass-multiplied thermal resistance of the HHF HS is 32% smaller compared with the pin fin heat sink (PF HS). These interesting results are mainly due to integrated effects of the mass-reduction, the surface area enhancement, and the heat pumping via the internal channel. Such better performances of HF HSs show the feasibility of alternatives to the conventional PF HS especially for passive cooling of LED lighting modules.


Author(s):  
Youngsuk Son ◽  
Monalisa Mazumder ◽  
Theodorian Borca-Tasciuc

Developing a fundamental understanding regarding energy flow across nanoscale interfaces is critical in realizing viable nanoelectronics device systems and efficient low-dimensional thermoelectric devices. This work presents investigations of the interface thermal resistance (ITR) in a nanoelectrode-on-substrate system using the DC heating as well as the 3ω method.


2013 ◽  
Vol 117 (46) ◽  
pp. 14576-14587 ◽  
Author(s):  
Sahika Inal ◽  
Leonardo Chiappisi ◽  
Jonas D. Kölsch ◽  
Mario Kraft ◽  
Marie-Sousai Appavou ◽  
...  

2017 ◽  
Vol 121 (1246) ◽  
pp. 1858-1878
Author(s):  
Anwar Ali ◽  
Khalil Ullah ◽  
Hafeez Ur Rehman ◽  
Inam Bari ◽  
Leonardo M. Reyneri

ABSTRACTRecently, universities and Small and Medium Enterprises (SMEs) have initiated the development of nanosatellites because of their low cost, small size and short development time. The challenging aspects for these satellites are their small surface area for heat dissipation due to their limited size. There is not enough space for mounting radiators for heat dissipation. As a result, thermal modelling becomes a very important element in designing a small satellite. The paper presents detailed and simplified generic thermal models for CubeSat panels and also for the complete satellite. The detailed model takes all thermal resistances associated with the respective layers into account, while in the simplified model, the layers with similar materials have been combined and are represented by a single thermal resistance. The proposed models are then applied to a CubeSat standard nanosatellite called AraMiS-C1, developed at Politecnico di Torino, Italy. Thermal resistance measured through both models is compared, and the results are similar. The absorbed power and the corresponding temperature differences between different points of the single panel and complete satellite are measured. In order to verify the theoretical results, thermal resistance of the AraMiS-C1 and its panels are measured through experimental set-ups. Theoretical and measured values are in close agreement.


Author(s):  
Lei Wang ◽  
Xudong Zhang ◽  
Dr. Jing Liu ◽  
Yixin Zhou

Abstract Liquid metal owns the highest thermal conductivity among all the currently available fluid materials. This property enables it to be a powerful coolant for the thermal management of large power device or high flux chip. In this paper, a high-efficiency heat dissipation system based on the electromagnetic driven rotational flow of liquid metal was demonstrated. The velocity distribution of the liquid metal was theoretically analyzed and numerically simulated. The results showed that the velocity was distributed unevenly along longitudinal section and the maximum velocity appears near the anode. On the temperature distribution profile of the heat dissipation system, the temperature on the electric heater side was much higher than the other regions and the role of the rotated liquid metal was to homogenize the temperature of the system. In addition, the thermal resistance model of the experimental device was established, and several relationships such as thermal resistance-power curve were experimentally measured. The heating power could be determined from the temperature-power relationship graph once the maximum control temperature was given. The heat dissipation method introduced in the paper provides a novel way for fabricating compact chip cooling system.


2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Mohd Riduan Jamalludin ◽  
◽  
Siti Khadijah Hubadillah ◽  
Zawati Harun ◽  
Muhamad Zaini Yunos ◽  
...  

This study investigates the effects of rice husk silica (RHS) as additive in the polysulfone membrane to enhance antifouling properties in membrane separation process. The performance (of what?) was evaluated in term of pure water flux (PWF), rejection and antifouling properties. The optimized of normalized flux (Jf /Jo) at different parameter in filtration (pH, ionic strength and tranmembrane-pressure) was carried out by using the response surface methodology (RSM). The results showed that the addition of 4 wt. % RHS give the highest flux at 300.50 L/m².hour (LMH). The highest rejection was found at 3 wt. % of RHS membrane with value 98% for UV254 and 96% for TOC. The optimal value of Jf/Jo was found at 0.62 with the condition of pH: 6.10, ionic strength: 0.05 mol/L and transmembrane-pressure: 2.67 bars. Optimize of RSM analysis from ANOVA also proved that the error of model is less than 0.05% which indicates that the model is significant.


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