Thermal Conducting Thermosets Driven by Molecular Structurally Enhanced Mesogen Interactions

Author(s):  
Arinola Isa Olamilekan ◽  
Hyeonuk Yeo
Keyword(s):  
2020 ◽  
Vol 40 (10) ◽  
pp. 859-867
Author(s):  
Yao Shi ◽  
Genlian Lin ◽  
Xi-Fei Ma ◽  
Xiao Huang ◽  
Jing Zhao ◽  
...  

AbstractHexagonal boron nitride (h-BN) nanoplatelets (0.6 μm in diameter and 100 nm in thickness) are introduced into epoxy resin to improve the polymer’s thermal conducting ability. As expected, the thermal conductivities (TCs) of the composites, especially the in-plane TCs, are significantly increased. The in-plane TC of the epoxy composites can reach 1.67 W/mK at only 0.53 wt% loading, indicating h-BN nanopletelets are very effective thermal fillers. However, after carefully studied the correlation of the TC improvement and filler content, a sudden drop of the TC around 0.53 wt% filler loading is observed. Such an unexpected decrease in TC has never been reported and is also found to be consistent with the Tg changes versus filler content. Similar trend is also observed in other 2-D nanofillers, such as graphene oxide, reduced graphene oxide, which may indicate it is a general phenomenon for 2-D nanofillers. SEM results suggest that such sudden drop in TC might be coming from the enrichment of these 2-D nanofillers in localized areas due to their tendency to form more ordered phase above certain concentrations.


Author(s):  
Boo Youn Lee

A direct differentiation method is presented for the shape design sensitivity analysis of axisymmetric thermal conducting solids. Based purely on the standard boundary integral equation (BIE) formulation, a new BIE is derived using the material derivative concept. Design derivatives in terms of shape change are directly calculated by solving the derived BIE. The present direct method has a computational advantage over the adjoint variable method, in the sense that it avoids the problem of solving for the adjoint system with the singular boundary condition. Numerical accuracy of the method is studied through three examples. The sensitivities by the present method are compared with analytic sensitivities for two problems of a hollow cylinder and a hollow sphere, and are then compared with those by finite differences for a thermal diffuser problem. As a practical application to numerical optimization, an optimal shape of the thermal diffuser to minimize the weight under a prescribed constraint is found by use of an optimization routine.


2013 ◽  
Vol 13 (5) ◽  
pp. 3307-3312 ◽  
Author(s):  
Tae-Eon Kim ◽  
Jin Chul Bae ◽  
Kwang Yeon Cho ◽  
Yong-Gun Shul ◽  
Chang Yeoul Kim

GCTs are a locally aggressive tumor that can result in significant pain and dysfunction through the disruption of bony and nearby soft tissue architecture. Although generally benign, these tumors have been shown to have 1-9% chance of metastasis and a local recurrence rate of up to 65%. For these reasons, appropriate treatment is essential to remove primary lesions as well as reduce the odds of metastatic disease and lower recurrence rates. Cryosurgery is a welldescribed technique used to achieve local control of primary GCTs. Modern cryoablation utilizes a cryoprobe to freeze surrounding tissues via release of a thermal conducting gas (argonhelium). The optimal technique for eradication of GCT is a widely debated topic rooted in rates of complications and tumor recurrence. Herein, we describe a case report of a 30-year-old female with a large distal femoral GCT that underwent intralesional curettage and adjunctive cryotherapy utilizing K-Y jelly as a semi-solid medium to transmit the freeze zone more evenly within the cavity. Following cryoablation, the cavity was filled with antibiotic loaded polymethyl methacrylate cement. This technique has scarcely been described in the literature and warrants further investigation.


Improvement of heat removal rate in heat exchanger using passive techniques is considered to be one of the most challenging task for engineers and scientist. In this study efficiency of the heat exchangers has been studied with TiO2 / water based nanofluid. The thermal properties, physical properties and heat removal efficiency of heat exchanger with nano-fluid as working fluid was investigated. Nanoparticle concentration of about 0.1 and 0.3 vol% was used. It was detected that the thermal conducting property and viscous property of the nanofluid increased proportionally with volume percentage. With the increased heat, the thermal conducting property increased while the viscous property of the nanofluid decreased. The heat removal rate on both shell outlet and tube outlet was estimated for different mass flow rate. The experiment results showed that with increased volume percentage and flow rate, the heat transfer performance improved. A maximum enhancement of 34% was observed at 0.3 vol% and 6l/min. Though there is increase in heat transfer rate the pressure dropped and pumping requirement increase with volume concentration and flow rate.


2020 ◽  
Vol 7 (2) ◽  
pp. 37-41
Author(s):  
Peter Drgoňa ◽  
Rastislav Štefún ◽  
Ľ. Štefke

<span style="font-family: 'Times New Roman',serif; font-size: 10pt; -ms-layout-grid-mode: line; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-GB">This article deals with the design and practical realization of a CNC device designed for the application of viscous materials, such as a thermal conducting paste. Paste is used for effective heat transfer what is essential in switched mode power supplies. However, its application on surface can be an issue. Designed CNC device serves for easier and more accurate application in production process using standard tubes.</span>


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