It has been shown recently that the Coulomb part of electromagnetic interactions is more important than the transverse propagation waves for the near-field enhancement of heat transfer between metal objects at a distance of order nanometers. Here we present a theory focusing solely on the Coulomb potential between electrons hopping among tight-binding sites. When the relevant systems are reduced to very small geometry, for example, a single site, the enhancement is much higher compared to a collection of them packed within a distance of a few Å. We credit this to the screening effect. This result may be useful in designing metal-based metamaterials to enhance heat transfer much higher.
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http://dx.doi.org/10.1103/PhysRevE.98.012118 | DOI Listing |
Sci Rep
December 2024
School of Materials Science and Engineering, Liaocheng University, Liaocheng, 252059, Shandong, China.
The welding of titanium alloys is an important topic in today's industrial field, and the interaction between the solder and the base material is crucial for the quality of the welded parts. The structural, elastic, electronic, and thermal properties of Ti-Al-Me (Me = Cu, Fe and Ni) alloys (TAMs) with the face-centered cubic structures were investigated using plane-wave pseudo potential method in the framework of density functional theory. Based on the calculated elastic constants combined with empirical and semi-empirical formulas, physical properties including ductility/brittleness, hardness and anisotropy were calculated.
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December 2024
Department of Mechanical Engineering, Qom University of Technology, Qom, 37195-1519, Iran.
This study investigates the use of multi-layered porous media (MLPM) to enhance thermal energy transfer within a counterflow double-pipe heat exchanger (DPHE). We conducted computational fluid dynamics (CFD) simulations on DPHEs featuring five distinct MLPM configurations, analyzed under both fully filled and partially filled conditions, alongside a conventional DPHE. The impact of various parameters such as porous layer arrangements, thickness, and flow Reynolds numbers on pressure drop, logarithmic mean temperature difference (LMTD), and performance evaluation criterion (PEC) was assessed.
View Article and Find Full Text PDFJ Food Sci
December 2024
Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Microstructural properties of wheat-based food materials change during baking. These alterations affect the final product's mechanical properties, physical attributes, and consumer satisfaction. Image processing and pore network modeling were used to analyze the variations in a cookie's microstructural properties during baking.
View Article and Find Full Text PDFMembranes (Basel)
December 2024
Department of Chemistry and Biomolecular Science, Gifu University, Gifu 501-1113, Japan.
In a previous study, we developed an integrated reaction system combining NH decomposition and CO methanation within a membrane reactor, significantly enhancing reactor performance through efficient H separation. Ru/Ba/γ-AlO and Ru/ZrO were employed as catalysts for each reaction. To ensure the accuracy and reliability of our results, they were validated through 1D models using FlexPDE Professional Version 7.
View Article and Find Full Text PDFBiomimetics (Basel)
November 2024
Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
In nature, engineering technology and daily life, wetting phenomena are widespread and have essential roles and significance. Bionics is becoming increasingly important nowadays and exploring the mechanism that influences biomimetic surface microstructure on droplet wetting process and heat and mass transfer characteristics is becoming more meaningful. In this paper, based on photolithography technology, SU-8 photoresist was used as raw material to prepare biomimetic surfaces with microstructures in various arrangements.
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