scholarly journals Graded thermal conductivity in 2D and 3D homogeneous hotspot systems

2022 ◽  
pp. 100605
Author(s):  
Chuang Zhang ◽  
Dengke Ma ◽  
Manyu Shang ◽  
Xiao Wan ◽  
Jing-Tao Lü ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
2D And 3D

scholarly journals Thermal Conductivity of Polymer Composites Filled with Nanofillers

2016 ◽  
Author(s):  
Raj Kiran
Keyword(s):  
Thermal Conductivity ◽  
Polymer Materials ◽  
Alumina Nanoparticles ◽  
3D Analysis ◽  
Finite Element Software ◽  
Rsa Algorithm ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
2D And 3D

Polymer nanocomposites are composed of polymer materials reinforced with nano fillers. In the present study the effective thermal conductivity of the composites filled with nanofillers has been investigated using commercially available finite element software ABAQUS 6.11. The nanofillers used were alumina particles and multi-walled carbon nanotubes (MWNTs) and the matrix was considered to be made of epoxy. For the analysis 2D and 3D Representative Volume Elements (RVEs) were generated using Random Sequential Adsorption (RSA) algorithm using MATLAB and Python scripts. Thermal conductivity was found out for 2D and 3D RVEs for different area and weight fractions respectively. Two different shapes of the alumina nanoparticles were considered: spherical (circular) and ellipsoidal (elliptical) for 3D (2D) analysis. It was found that the thermal conductivity was increased with the addition of nanofillers. The increase in thermal conductivity was approximately same for both types of inclusions at corresponding area or weight fractions in 2D or 3D analysis. The results showed that addition of MWNTs to the composites lead to a significant increase in thermal conductivity than spherical or ellipsoidal inclusions.

scholarly journals Polytope Sector-Based Synthesis and Analysis of Microstructural Architectures With Tunable Thermal Conductivity and Expansion

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Jonathan B. Hopkins ◽  
Yuanping Song ◽  
Howon Lee ◽  
Nicholas X. Fang ◽  
Christopher M. Spadaccini
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Material Property ◽  
Analytical Methods ◽  
Positive Zero ◽  
Bulk Property ◽  
Element Analysis ◽  
Thermal Expansion Coefficients ◽  
Projection Microstereolithography ◽  
2D And 3D

The aim of this paper is to (1) introduce an approach, called polytope sector-based synthesis (PSS), for synthesizing 2D or 3D microstructural architectures that exhibit a desired bulk-property directionality (e.g., isotropic, cubic, orthotropic, etc.), and (2) provide general analytical methods that can be used to rapidly optimize the geometric parameters of these architectures such that they achieve a desired combination of bulk thermal conductivity and thermal expansion properties. Although the methods introduced can be applied to general beam-based microstructural architectures, we demonstrate their utility in the context of an architecture that can be tuned to achieve a large range of extreme thermal expansion coefficients—positive, zero, and negative. The material-property-combination region that can be achieved by this architecture is determined within an Ashby-material-property plot of thermal expansion versus thermal conductivity using the analytical methods introduced. These methods are verified using finite-element analysis (FEA) and both 2D and 3D versions of the design have been fabricated using projection microstereolithography.

scholarly journals Polytope Sector-Based Synthesis and Analysis of Microarchitectured Materials With Tunable Thermal Conductivity and Expansion

2015 ◽  
Author(s):  
Jonathan B. Hopkins ◽  
Howon Lee ◽  
Nicholas X. Fang ◽  
Christopher M. Spadaccini
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Material Property ◽  
Analytical Methods ◽  
Positive Zero ◽  
Bulk Property ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Projection Microstereolithography ◽  
2D And 3D

The aim of this paper is to (1) introduce an approach, called Polytope Sector-based Synthesis, for synthesizing 2D or 3D microstructural architectures that exhibit a desired bulk-property directionality (e.g., isotropic, cubic, orthotropic, etc.), and (2) provide general analytical methods that can be used to rapidly optimize the geometric parameters of these architectures such that they achieve a desired combination of bulk thermal conductivity and thermal expansion properties. Although the methods introduced can be applied to general beam-based microstructural architectures, we demonstrate their utility in the context of an architecture that can be tuned to achieve a large range of extreme thermal expansion coefficients — positive, zero, and negative. The material-property-combination region that can be achieved by this architecture is determined within an Ashby-material-property plot of thermal expansion vs. thermal conductivity using the analytical methods introduced. Both 2D and 3D versions of the design have been fabricated using projection microstereolithography.

Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

1991 ◽  
Vol 49 ◽  
pp. 870-871
Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter
Keyword(s):  
Colony Growth ◽  
Dark Field ◽  
Dark Side ◽  
Silicide Phase ◽  
Strain Fields ◽  
Near Surface ◽  
Unknown Composition ◽  
Secondary Precipitates ◽  
20 Nm ◽  
2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

Covalent organic frameworks: an ideal platform for designing ordered materials and advanced applications

2021 ◽  
Author(s):  
Ruoyang Liu ◽  
Ke Tian Tan ◽  
Yifan Gong ◽  
Yongzhi Chen ◽  
Zhuoer Li ◽  
...  
Keyword(s):  
Covalent Organic Frameworks ◽  
2D And 3D ◽  
Advanced Applications

Covalent organic frameworks offer a molecular platform for integrating organic units into periodically ordered yet extended 2D and 3D polymers to create topologically well-defined polygonal lattices and built-in discrete micropores and/or mesopores.

Evaluating Alternate Visualization Methods for Microsurgery: 2D and 3D Optical Microscopes and Flat-Panel Displays

2012 ◽  
Author(s):  
Michael Sackllah ◽  
Denny Yu ◽  
Charles Woolley ◽  
Steven Kasten ◽  
Thomas J. Armstrong
Keyword(s):  
Flat Panel Displays ◽  
Flat Panel ◽  
2D And 3D

Alternative 2D and 3D Visualization Methods for Microsurgery: Posture, Performance, and Discomfort Analysis

2011 ◽  
Author(s):  
Denny Yu ◽  
Michael Sackllah ◽  
Charles Woolley ◽  
Steven Kasten ◽  
Thomas J. Armstrong
Keyword(s):  
3D Visualization ◽  
2D And 3D
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