Electrical fatigue behavior of NBT-BT-xKNN ferroelectrics: effect of ferroelectric phase transformations and oxygen vacancies

2020 ◽  
Vol 8 (11) ◽  
pp. 3887-3896 ◽  
Author(s):  
Xi Shi ◽  
Nitish Kumar ◽  
Mark Hoffman
Keyword(s):  
Phase Transformations ◽  
Degradation Rate ◽  
Oxygen Vacancies ◽  
Ferroelectric Phase ◽  
Fatigue Behavior ◽  
Surface Damage ◽  
Micro Scale ◽  
Scale Surface

The reduction of degradation rate at high cycles indicates the subsequent contribution from micro-scale surface damage, leading to irreversible fatigue.

scholarly journals Experimental study of the effects of wire EDM on the characteristics of ferritic steel, at a micro-scale on the contour cut surface

2018 ◽  
Vol 115 (4) ◽  
pp. 413
Author(s):  
Nida Naveed
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Surface Characteristics ◽  
Surface Damage ◽  
Cutting Process ◽  
Contour Method ◽  
X Ray Diffraction ◽  
Micro Scale ◽  
Macro Scale ◽  
Cut Surface

This study, on a micro-scale, of the WEDM cut surfaces of specimens to which the contour method of residual stress measurement is being applied provides detailed information about the effects of the cutting process on the surface quality. This is defined by a combination of several parameters: variation in surface contour profile, sub-surface damage and surface texture. Measurements were taken at the start, the middle and at the end of the cut. This study shows that during WEDM cutting, a thin layer, extending to a depth of a few micrometres below the surface of the cut, is transformed. This layer is known as the recast layer. Using controlled-depth etching and X-ray diffraction, it is shown that this induces an additional tensile residual stress, parallel to the plane of the cut surface. The WEDM cut surface and sub-surface characteristics are also shown to vary along the length of the cut. Moreover, these micro-scale changes were compared with macro-scale residual stress results and provides an indication of the point at which the changes occurred by cutting process can be significantly relative to the macro-scale residual stress in a specimen.

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.

Static and Fatigue Behavior of Thick Pultruded GFRP Plates with Surface Damage

2009 ◽  
Vol 14 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Yoshiki Tanaka ◽  
Jun Murakoshi ◽  
Yuko Nagaya ◽  
Tetsuya Watanabe
Keyword(s):  
Fatigue Behavior ◽  
Surface Damage

Coexistence of nano-scale phase separation and micro-scale surface crystallization in Gd2O3–WO3–B2O3 glasses

2013 ◽  
Vol 381 ◽  
pp. 17-22 ◽  
Author(s):  
Y. Taki ◽  
K. Shinozaki ◽  
T. Honma ◽  
T. Komatsu ◽  
L. Aleksandrov ◽  
...  
Keyword(s):  
Phase Separation ◽  
Surface Crystallization ◽  
Micro Scale ◽  
Nano Scale ◽  
Scale Surface

Effects of Bio-Inspired Micro-Scale Surface Patterns on the Profile Losses in a Linear Cascade

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Qiang Liu ◽  
Shan Zhong ◽  
Lin Li
Keyword(s):  
Pressure Loss ◽  
Reynolds Numbers ◽  
Loss Reduction ◽  
Turning Angle ◽  
Low Reynolds Numbers ◽  
Linear Cascade ◽  
Micro Scale ◽  
Pressure Loss Coefficient ◽  
Surface Patterns ◽  
Scale Surface

Abstract In this paper, we investigated the effects of herringbone riblets, a type of bio-inspired micro-scale surface patterns, on pressure losses and flow turning angles in a linear cascade over a range of low Reynolds numbers from 0.50 × 105 to 1.50 × 105 and at three different incidence angles. Our experiments showed that despite their micro-scale size, herringbone riblets produced a significant reduction in pressure loss and a substantial increase in flow turning angle except at the low end of the Reynolds numbers tested. In comparison to the baseline case without riblets, the highest reduction in the zone-averaged pressure loss coefficient behind one flow passage was 36.4% which was accompanied by a 4.1 deg increase in the averaged turning angle. The loss reduction was caused by a decrease in γmax at α = −1 deg, a narrower wake zone at α = 9 deg and a mixture of both at α = 4 deg due to the suppression of flow separation on the blade suction surface. It was also noted that such a significant improvement was always accompanied by the appearance of a serrated wake structure in the contours of pressure loss coefficient in which the region with a higher loss reduction occurring directly behind the divergent region of herringbone riblets. The observed improvement in cascade performance was attributed to the secondary flow motion produced by herringbone riblets which energizes the boundary layer. Overall, this work has produced convincing experimental evidence that herringbone riblets could be potentially used as passive flow control devices for reducing flow separation in compressors at low Reynolds numbers.

scholarly journals Micro-scale surface-patterning influences biofilm formation

2009 ◽  
Vol 12 (3) ◽  
Author(s):  
Guimel M. Kappell ◽  
James P. Grover ◽  
Thomas H. Chrzanowski
Keyword(s):  
Biofilm Formation ◽  
Surface Patterning ◽  
Micro Scale ◽  
Scale Surface

Evolution of black silicon nano- and micro-scale surface topologies upon femtosecond laser irradiation

2010 ◽  
Author(s):  
S. I. Kudryashov ◽  
E. V. Golosov ◽  
A. A. Ionin ◽  
Yu. R. Kolobov ◽  
A. E. Ligachev ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Femtosecond Laser Irradiation ◽  
Black Silicon ◽  
Micro Scale ◽  
Scale Surface
Sign in / Sign up

Export Citation Format

Share Document