scholarly journals Highly Thermal Conductive and Electrical Insulating Epoxy Composites with a Three-Dimensional Filler Network by Sintering Silver Nanowires on Aluminum Nitride Surface

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 694
Author(s):  
Wondu Lee ◽  
Jooheon Kim
Keyword(s):  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Silver Nanowires ◽  
Three Dimensional ◽  
Silver Nanowire ◽  
Thermal Interface Material ◽  
Processing Unit ◽  
Central Processing ◽  
Conductive Composites ◽  
3D Network

In this study, a new fabrication technique for three-dimensional (3D) filler networks was employed for the first time to prepare thermally conductive composites. A silver nanowire (AgNW)– aluminum nitride (AlN) (AA) filler was produced by a polyol method and hot-pressed in mold to connect the adjacent fillers by sintering AgNWs on the AlN surface. The sintered AA filler formed a 3D network, which was subsequently impregnated with epoxy (EP) resin. The fabricated EP/AA 3D network composite exhibited a perpendicular direction thermal conductivity of 4.49 W m−1 K−1 at a filler content of 400 mg (49.86 vol.%) representing an enhancement of 1973% with respect to the thermal conductivity of neat EP (0.22 W m−1 K−1). Moreover, the EP/AA decreased the operating temperature of the central processing unit (CPU) from 86.2 to 64.6 °C as a thermal interface material (TIM). The thermal stability was enhanced by 27.28% (99 °C) and the composites showed insulating after EP infiltration owing to the good insulation properties of AlN and EP. Therefore, these fascinating thermal and insulating performances have a great potential for next generation heat management application.

scholarly journals FEM using projection of physical properties suitable for movement modeling and optimization processes

2020 ◽  
Vol 39 (5) ◽  
pp. 1185-1199
Author(s):  
Baptiste Ristagno ◽  
Dominique Giraud ◽  
Julien Fontchastagner ◽  
Denis Netter ◽  
Noureddine Takorabet ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Transient State ◽  
Mathematical Function ◽  
Processing Unit ◽  
Time Saving ◽  
Content Type ◽  
Central Processing ◽  
Cpu Time ◽  
Simple Geometry ◽  
Evaluation Time

Purpose Optimization processes and movement modeling usually require a high number of simulations. The purpose of this paper is to reduce global central processing unit (CPU) time by decreasing each evaluation time. Design Methodology Approach Remeshing the geometry at each iteration is avoided in the proposed method. The idea consists in using a fixed mesh on which functions are projected to represent geometry and supply. Findings Results are very promising. CPU time is reduced for three dimensional problems by almost a factor two, keeping a low relative deviation from usual methods. CPU time saving is performed by avoiding meshing step and also by a better initialization of iterative resolution. Optimization, movement modeling and transient-state simulation are very efficient and give same results as usual finite element method. Research Limitations Implications The method is restricted to simple geometry owing to the difficulty of finding spatial mathematical function describing the geometry. Moreover, a compromise between imprecision, caused by the boundary evaluation, and time saving must be found. Originality Value The method can be applied to optimize rotating machines design. Moreover, movement modeling is performed by shifting functions corresponding to moving parts.

Three-Dimensional Graphite Filled Poly(Vinylidene Fluoride) Composites with Enhanced Strength and Thermal Conductivity

2020 ◽  
Vol 842 ◽  
pp. 63-68
Author(s):  
Xiao Zhang ◽  
Jian Zheng ◽  
Yong Qiang Du ◽  
Chun Ming Zhang
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Energetic Materials ◽  
High Performance ◽  
Vinylidene Fluoride ◽  
3D Structure ◽  
Three Dimensional ◽  
3D Network ◽  
Poly Vinylidene Fluoride ◽  
Polymer Bonded Explosives

Three-dimensional (3D) network structure has been recognized as an efficient approach to enhance the mechanical and thermal conductive properties of polymeric composites. However, it has not been applied in energetic materials. In this work, a fluoropolymer based composite with vertically oriented and interconnected 3D graphite network was fabricated for polymer bonded explosives (PBXs). Here, the graphite and graphene oxide platelets were mixed, and self-assembled via rapid freezing and using crystallized ice as the template. The 3D structure was finally obtained by freezing-dry, and infiltrating with polymer. With the increasing of filler fraction and cooling rate, the thermal conductivity of the polymer composite was significantly improved to 2.15 W m-1 K-1 by 919% than that of pure polymer. Moreover, the mechanical properties, such as tensile strength and elastic modulus, were enhanced by 117% and 563%, respectively, when the highly ordered structure was embedded in the polymer. We attribute the increased thermal and mechanical properties to this 3D network, which is beneficial to the effective heat conduction and force transfer. This study supports a desirable way to fabricate the strong and thermal conductive fluoropolymer composites used for the high-performance polymer bonded explosives (PBXs).

A thermal interface material based on foam-templated three-dimensional hierarchical porous boron nitride

2018 ◽  
Vol 6 (36) ◽  
pp. 17540-17547 ◽  
Author(s):  
Zhilin Tian ◽  
Jiajia Sun ◽  
Shaogang Wang ◽  
Xiaoliang Zeng ◽  
Shuang Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Three Dimensional ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Hierarchical Porous ◽  
Templated Method

A high thermal conductivity boron nitride based thermal interface material was developed by a foam-templated method.

Multifunctional Liquid Crystal Polymeric Composites Embedded With Graphene Nano Platelets

2011 ◽  
Author(s):  
Muhammad Omer Khan ◽  
Ellen Chan ◽  
Siu N. Leung ◽  
Hani Naguib ◽  
Francis Dawson ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Crystal ◽  
Heat Dissipation ◽  
Three Dimensional ◽  
Cost Effective ◽  
Polymeric Composites ◽  
Potential Cost ◽  
Conductive Composites ◽  
The Matrix ◽  
Thermally Conductive

This paper studies the development of new multifunctional liquid crystal polymeric composites filled with graphene nano platelets (GNPs) for electronic packaging applications. A series of parametric studies were conducted to study the effect of GNP content on the thermal conductivity of LCP-based nanocomposites. Graphene, ranging from 10 wt. % to 50 wt. %, were melt-compounded with LCP using a twin-screw compounder. The extrudates were ground and compression molded into small disc-shaped specimens. The thermal conductivity of LCP matrix was observed to have increased by more than 1000% where as the electrical conductivity increased by 13 orders of magnitude with the presence of 50 wt% GNP fillers. The morphology of the composites was analyzed using SEM micrographs to observe the dispersion of filler within the matrix. These thermally conductive composites represent potential cost-effective materials to injection mold three-dimensional, net-shape microelectronic enclosures with superior heat dissipation performance.

An Accelerated 3D Navier–Stokes Solver for Flows in Turbomachines

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Tobias Brandvik ◽  
Graham Pullan
Keyword(s):  
Graphics Processing Units ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Linear Scaling ◽  
Test Case ◽  
Processing Unit ◽  
Central Processing ◽  
Order Of Magnitude ◽  
Graphics Processing ◽  
Good Agreement

A new three-dimensional Navier–Stokes solver for flows in turbomachines has been developed. The new solver is based on the latest version of the Denton codes but has been implemented to run on graphics processing units (GPUs) instead of the traditional central processing unit. The change in processor enables an order-of-magnitude reduction in run-time due to the higher performance of the GPU. The scaling results for a 16 node GPU cluster are also presented, showing almost linear scaling for typical turbomachinery cases. For validation purposes, a test case consisting of a three-stage turbine with complete hub and casing leakage paths is described. Good agreement is obtained with previously published experimental results. The simulation runs in less than 10 min on a cluster with four GPUs.

An Accelerated 3D Navier-Stokes Solver for Flows in Turbomachines

2009 ◽  
Author(s):  
Tobias Brandvik ◽  
Graham Pullan
Keyword(s):  
Graphics Processing Units ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Linear Scaling ◽  
Test Case ◽  
Processing Unit ◽  
Central Processing ◽  
Order Of Magnitude ◽  
Graphics Processing ◽  
Good Agreement

A new three-dimensional Navier-Stokes solver for flows in turbomachines has been developed. The new solver is based on the latest version of the Denton codes, but has been implemented to run on Graphics Processing Units (GPUs) instead of the traditional Central Processing Unit (CPU). The change in processor enables an order-of-magnitude reduction in run-time due to the higher performance of the GPU. Scaling results for a 16 node GPU cluster are also presented, showing almost linear scaling for typical turbomachinery cases. For validation purposes, a test case consisting of a three-stage turbine with complete hub and casing leakage paths is described. Good agreement is obtained with previously published experimental results. The simulation runs in less than 10 minutes on a cluster with four GPUs.

scholarly journals Accelerating 3D Medical Image Segmentation by Adaptive Small-Scale Target Localization

2021 ◽  
Vol 7 (2) ◽  
pp. 35
Author(s):  
Boris Shirokikh ◽  
Alexey Shevtsov ◽  
Alexandra Dalechina ◽  
Egor Krivov ◽  
Valery Kostjuchenko ◽  
...  
Keyword(s):  
Image Segmentation ◽  
Graphics Processing Units ◽  
Medical Image ◽  
State Of The Art ◽  
Three Dimensional ◽  
Medical Image Segmentation ◽  
Small Scale ◽  
Processing Unit ◽  
Central Processing ◽  
Lung Cancer Diagnosis

The prevailing approach for three-dimensional (3D) medical image segmentation is to use convolutional networks. Recently, deep learning methods have achieved human-level performance in several important applied problems, such as volumetry for lung-cancer diagnosis or delineation for radiation therapy planning. However, state-of-the-art architectures, such as U-Net and DeepMedic, are computationally heavy and require workstations accelerated with graphics processing units for fast inference. However, scarce research has been conducted concerning enabling fast central processing unit computations for such networks. Our paper fills this gap. We propose a new segmentation method with a human-like technique to segment a 3D study. First, we analyze the image at a small scale to identify areas of interest and then process only relevant feature-map patches. Our method not only reduces the inference time from 10 min to 15 s but also preserves state-of-the-art segmentation quality, as we illustrate in the set of experiments with two large datasets.

scholarly journals Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yongqiang Guo ◽  
Hua Qiu ◽  
Kunpeng Ruan ◽  
Yali Zhang ◽  
Junwei Gu
Keyword(s):  
Thermal Conductivity ◽  
Electromagnetic Interference ◽  
Composite Films ◽  
Expanded Graphite ◽  
Electric Heating ◽  
Processing Unit ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Heat Accumulation ◽  
Central Processing

AbstractThe development of lightweight and integration for electronics requires flexible films with high thermal conductivity and electromagnetic interference (EMI) shielding to overcome heat accumulation and electromagnetic radiation pollution. Herein, the hierarchical design and assembly strategy was adopted to fabricate hierarchically multifunctional polyimide composite films, with graphene oxide/expanded graphite (GO/EG) as the top thermally conductive and EMI shielding layer, Fe3O4/polyimide (Fe3O4/PI) as the middle EMI shielding enhancement layer and electrospun PI fibers as the substrate layer for mechanical improvement. PI composite films with 61.0 wt% of GO/EG and 23.8 wt% of Fe3O4/PI exhibits high in-plane thermal conductivity coefficient (95.40 W (m K)−1), excellent EMI shielding effectiveness (34.0 dB), good tensile strength (93.6 MPa) and fast electric-heating response (5 s). The test in the central processing unit verifies PI composite films present broad application prospects in electronics fields.

A Hybrid Optimization Based on GPU Parallel Computing Method and its Application of Three Dimensional Large Eddy Simulations

2013 ◽  
Vol 275-277 ◽  
pp. 2589-2594 ◽  
Author(s):  
Yu Xuan Zhang ◽  
Song Ping Wu
Keyword(s):  
High Speed ◽  
Data Transfer ◽  
Three Dimensional ◽  
Processing Unit ◽  
Desktop Computer ◽  
Central Processing ◽  
Eddy Simulation ◽  
Turbulence Flow ◽  
Large Eddy ◽  
Optimization Schemes

Using compute Unified device architecture (CUDA), a traditional computational fluid dynamics (CFD) program is paralleled and optimized based on graphic processing unit (GPU). The calculation process is divided into two parts as serial and parallel. Their main characteristics are analyzed and different optimization schemes are given. CPU (central processing unit) and GPU work respectively as flow control and high-speed parallel computation. Bandwidth between devices is applied effectively. Data transfer between devices is moderately improved to simplify algorithm. Finally, the method is verified by simulating a three-dimensional isotropic homogeneous turbulence flow field. The calculation uses large eddy simulation (LES) method with secondary filter and solves the three-dimensional N-S equations. The maximum grid number achieves 8,000,000 and takes 33 seconds each step. All calculations are using ordinary single desktop computer, optimized acceleration ratio can reach 9.

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