scholarly journals Texture density aftereffect is bidirectional

2017 ◽  
Vol 17 (10) ◽  
pp. 1086
Author(s):  
Hua-Chun Sun ◽  
Frederick Kingdom ◽  
Curtis Baker
Keyword(s):  
Texture Density

Experimental study on the effect of surface texture on tribological properties of nanodiamond films under water lubrication

2021 ◽  
pp. 135065012110334
Author(s):  
Ying Yan ◽  
Xuelin Lei ◽  
Yun He
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Surface Texture ◽  
Diamond Film ◽  
Diamond Films ◽  
Nanocrystalline Diamond ◽  
Water Contact ◽  
Texture Density ◽  
Short Run

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.

scholarly journals Drops bouncing off macro-textured superhydrophobic surfaces

2017 ◽  
Vol 824 ◽  
pp. 866-885 ◽  
Author(s):  
Ali Mazloomi Moqaddam ◽  
Shyam S. Chikatamarla ◽  
Iliya V. Karlin
Keyword(s):  
Contact Time ◽  
Numerical Study ◽  
Three Dimensional ◽  
Superhydrophobic Surfaces ◽  
Nonlinear Behaviour ◽  
Textured Surfaces ◽  
Texture Density ◽  
Wide Range ◽  
Quantitative Manner ◽  
The Impact

Recent experiments with droplets impacting macro-textured superhydrophobic surfaces revealed new regimes of bouncing with a remarkable reduction of the contact time. Here we present a comprehensive numerical study that reveals the physics behind these new bouncing regimes and quantifies the roles played by various external and internal forces. For the first time, accurate three-dimensional simulations involving realistic macro-textured surfaces are performed. After demonstrating that simulations reproduce experiments in a quantitative manner, the study is focused on analysing the flow situations beyond current experiments. We show that the experimentally observed reduction of contact time extends to higher Weber numbers, and analyse the role played by the texture density. Moreover, we report a nonlinear behaviour of the contact time with the increase of the Weber number for imperfectly coated textures, and study the impact on tilted surfaces in a wide range of Weber numbers. Finally, we present novel energy analysis techniques that elaborate and quantify the interplay between the kinetic and surface energy, and the role played by the dissipation for various Weber numbers.

scholarly journals Optimization of Texture Density Distribution of Carbide Alloy Micro-Textured Ball-End Milling Cutter Based on Stress Field

2020 ◽  
Vol 10 (3) ◽  
pp. 818
Author(s):  
Minli Zheng ◽  
Chunsheng He ◽  
Shucai Yang
Keyword(s):  
Wear Resistance ◽  
Stress Field ◽  
Density Distribution ◽  
Titanium Alloys ◽  
Contact Area ◽  
End Milling ◽  
Variable Density ◽  
Milling Cutter ◽  
Ball End Milling ◽  
Texture Density

The insertion of micro-textures plays a role in reducing friction and increasing wear resistance of the cutters, which also has a certain impact on the stress field of the cutter during milling. Therefore, in order to study the mechanisms of friction reduction and wear resistance of micro-textured cutters in high speed cutting of titanium alloys, the dynamic characteristics of the instantaneous stress field during the machining of titanium alloys with micro-textured cutters were studied by changing the distribution density of the micro-textures on the cutter. First, the micro-texture insertion area of the ball-end milling cutter was theoretically analyzed. Then, variable density micro-textured ball-end milling cutters and non-texture cutters were used to cut titanium alloy, and the mathematical model of milling force and cutter-chip contact area was established. Then, the stress density functions of different micro-texture density cutters and non-texture cutters were established to simulate the stress fields of variable density micro-textured ball-end milling cutters and non-texture cutters. Finally, the genetic algorithm was used to optimize the variable density distribution of micro-textured cutters in which the instantaneous stress field of the cutters was taken as the optimization objective. The optimal solution for the variable density distribution of the micro-textured cutter in the cutter-chip tight contact area was obtained as follows: the texture distribution densities in the first, second, and third areas are second, and third areas are 0.0905, 0.0712, and 0.0493, respectively.

Depth Discrimination in Rats on Visual Cliffs

1964 ◽  
Vol 19 (2) ◽  
pp. 423-426 ◽  
Author(s):  
Doris C. Dehardt ◽  
David L. Whitney
Keyword(s):  
Visual Cliff ◽  
Visual Depth ◽  
Open Area ◽  
Deep Side ◽  
Open Model ◽  
Additional Information ◽  
Depth Discrimination ◽  
Texture Density ◽  
Shallow Side

On an open visual cliff rats significantly preferred the shallow side while on an otherwise comparable closed cliff they did not, suggesting either that depth discrimination is enhanced by the additional information provided by the deep side of the open model, or that animals merely avoided the large open area of the deep side. The latter suggests that side preferences in open model cliffs are not necessarily valid indicators of visual depth discriminability in rats. Texture density was not a sufficient cue for depth discriminability as indicated by the preference of Ss for 1-in. checks in both 3-in. vs 1-in. and 1-in. vs ¼-in. comparison tests.

Optical Flow and Texture Variables Useful for Detecting Changes in Simulated Self Motion

1983 ◽  
Vol 27 (12) ◽  
pp. 996-1000
Author(s):  
Dean H. Owen ◽  
Lawrence J. Hettinger ◽  
Shirley B. Tobias ◽  
Lawrence Wolpert ◽  
Rik Warren
Keyword(s):  
Optical Flow ◽  
Flow Pattern ◽  
High Speed ◽  
Flight Simulator ◽  
Practical Relevance ◽  
Motion Information ◽  
Flow Acceleration ◽  
Level Flight ◽  
Texture Density ◽  
Self Motion

Several methods are presented for breaking linkages among global optical flow and texture variables in order to assess their usefulness in experiments requiring observers to distinguish change in speed or heading of simulated self motion from events representing constant speed or level flight. Results of a series of studies testing for sensitivity to flow acceleration or deceleration, flow-pattern expansion variables, and the distribution of optical texture density are presented. Theoretical implications for determining the metrics of visual self-motion information, and practical relevance for pilot and flight simulator evaluation and for low-level, high-speed flight are discussed.

scholarly journals Salience from feature contrast: variations with texture density

2000 ◽  
Vol 40 (23) ◽  
pp. 3181-3200 ◽  
Author(s):  
Hans-Christoph Nothdurft
Keyword(s):  
Texture Density
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