scholarly journals A highly stretchable and robust non-fluorinated superhydrophobic surface

2017 ◽  
Vol 5 (31) ◽  
pp. 16273-16280 ◽  
Author(s):  
Jie Ju ◽  
Xi Yao ◽  
Xu Hou ◽  
Qihan Liu ◽  
Yu Shrike Zhang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Superhydrophobic Surface ◽  
Silicone Elastomer ◽  
Micro Scale ◽  
Highly Stretchable ◽  
Silica Microparticles ◽  
Scale Surface

A stretchable, rub-proof superhydrophobic surface was realized by a chemically bonded silicone elastomer network covering the surface of silica microparticles to form enhanced micro-scale surface roughness.

scholarly journals In Situ Measurements of Micro-Scale Surface Roughness of Sea Ice

ARCTIC ◽  
1991 ◽  
Vol 44 (5) ◽  
Author(s):  
J.S. Paterson ◽  
B. Brisco ◽  
S. Argus ◽  
G. Jones
Keyword(s):  
Surface Roughness ◽  
Sea Ice ◽  
Micro Scale ◽  
Scale Surface

scholarly journals Thermo-Hydraulic Characteristics of Micro-Scale Surface Roughness Topology of Additively Manufactured Surface Model: Modal Decomposition Perspective

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7650
Author(s):  
Sina Lohrasbi ◽  
René Hammer ◽  
Werner Eßl ◽  
Georg Reiss ◽  
Stefan Defregger ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Additive Manufacturing ◽  
Numerical Study ◽  
Rapid Development ◽  
Surface Model ◽  
Micro Scale ◽  
Roughness Elements ◽  
Flow Mechanisms ◽  
Scale Surface

As a consequence of rapid development of additive manufacturing (3D printing) methods, the academic/industrial demand has been continuously increasing. One field of application is the manufacturing of heat exchanging devices using this promising method. In this regard, understanding the underlying mechanisms from a thermo-hydraulic viewpoint becomes important. Therefore, in this study, scale-resolving large eddy simulation (LES) is applied to reveal the flow details in combination with a model of roughness topology occurring in additive manufacturing. To process the transient LES results, proper orthogonal decomposition (POD) is used to extract the coherent flow structures, and the extended POD is used to rank the flow modes based on thermal importance. The main aim of the present work is to go beyond the conventionally applied methodologies used for the evaluation of surface roughness, i.e., averaged numerical study or experimental overall performance evaluation of the flow/thermal response of additively manufactured surfaces in heat exchangers. This is necessary to reveal the underlying flow mechanisms hidden in the conventional studies. In this study, the behavior of the flow over the micro-scale surface roughness model and its effects on heat transfer are studied by assuming cone-shaped roughness elements with regular placement as the dominant surface roughness structures. The major discussions reveal the footprint of flow mechanisms on the heat transfer coefficient spatial modes on the rough surface. Moreover, comparative study on the flow/thermal behavior at different levels of roughness heights shows the key role of the height-to-base-diameter ratio of the roughness elements in thermal performance.

Integrin β1 activation by micro-scale curvature promotes pro-angiogenic secretion of human mesenchymal stem cells

2017 ◽  
Vol 5 (35) ◽  
pp. 7415-7425 ◽  
Author(s):  
Zhengdong Li ◽  
Weiwei Wang ◽  
Xun Xu ◽  
Karl Kratz ◽  
Jie Zou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Human Mesenchymal Stem Cells ◽  
Β1 Integrin ◽  
Integrin Β1 ◽  
Micro Scale ◽  
Culture Substrate ◽  
A Cell ◽  
Scale Surface ◽  
Cell Culture Substrate

A cell culture substrate with micro-scale surface curvature promotes β1 integrin activation and pro-angiogenic secretion of mesenchymal stem cells.

scholarly journals Effects of decimetre-scale surface roughness on L-band Brightness Temperature of Sea Ice

2019 ◽  
Author(s):  
Maciej Miernecki ◽  
Lars Kaleschke ◽  
Nina Maaß ◽  
Stefan Hendricks ◽  
Sten Schmidl Søbjrg
Keyword(s):  
Surface Roughness ◽  
Sea Ice ◽  
Brightness Temperature ◽  
Large Scale ◽  
Ice Thickness ◽  
Emission Model ◽  
Vertical Polarization ◽  
Sea Ice Thickness ◽  
L Band ◽  
Scale Surface

Abstract. Sea ice thickness measurements with L-band radiometry is a technique which allows daily, weather-independent monitoring of the polar sea ice cover. The sea-ice thickness retrieval algorithms relay on the sensitivity of the L-band brightness temperature to sea-ice thickness. In this work, we investigate the decimetre-scale surface roughness as a factor influencing the L-band emissions from sea ice. We used an airborne laser scanner to construct a digital elevation model of the sea ice surface. We found that the probability density function of surface slopes is exponential for a range of degrees of roughness. Then we applied the geometrical optics, bounded with the MIcrowave L-band LAyered Sea ice emission model in the Monte Carlo simulation to simulate the effects of surface roughness. According to this simulations, the most affected by surface roughness is the vertical polarization around Brewster's angle, where the decrease in brightness temperature can reach 8 K. The vertical polarization for the same configuration exhibits a 4 K increase. The near-nadir angles are little affected, up to 2.6 K decrease for the most deformed ice. Overall the effects of large-scale surface roughness can be expressed as a superposition of two factors: the change in intensity and the polarization mixing. The first factor depends on surface permittivity, second shows little dependence on it. Comparison of the brightness temperature simulations with the radiometer data does not yield definite results.

scholarly journals Assembly Mechanism and the Morphological Analysis of the Robust Superhydrophobic Surface

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 472 ◽  
Author(s):  
Doeun Kim ◽  
Arun Sasidharanpillai ◽  
Ki Hoon Yun ◽  
Younki Lee ◽  
Dong-Jin Yun ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Superhydrophobic Surface ◽  
Spray Coating ◽  
Silica Nanoparticle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Thin Layers ◽  
Superhydrophobic Surfaces ◽  
Assembly Mechanism ◽  
Developed Surface

Robust superhydrophobic surfaces are fabricated on different substrates by a scalable spray coating process. The developed superhydrophobic surface consists of thin layers of surface functionalized silica nanoparticle (SiO2) bound to the substrate by acrylate-polyurethane (PU) binder. The influence of the SiO2/PU ratio on the superhydrophobicity, and the robustness of the developed surface, is systematically analyzed. The optimized SiO2/PU ratio for prepared superhydrophobic surfaces is obtained between 0.9 and 1.2. The mechanism which yields superhydrophobicity to the surface is deduced for the first time with the help of scanning electron microscopy and profilometer. The effect of mechanical abrasion on the surface roughness and superhydrophobicity are analyzed by using profilometer and contact angle measurement, respectively. Finally, it is concluded that the binder plays a key role in controlling the surface roughness and superhydrophobicity through the capillary mechanism. Additionally, the reason for the reduction in performance is also discussed with respect to the morphology variation.

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