Comprehensive study of relationships between surface morphology parameters and contact stress

Author(s):  
Duo Yang ◽  
Jinyuan Tang ◽  
Wei Zhou ◽  
Yuqin Wen
PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0257850
Author(s):  
Guangyuan Ge ◽  
Fenfen Liu ◽  
Gengpei Zhang

Running-in is an important and relatively complicated process. The surface morphology prior to running-in affects the surface morphology following the running-in process, which in turn influences the friction and wear characteristics of the workpiece. Therefore, the establishment of a model for running-in surface morphology prediction is important to investigate the process and optimize the surface design. Black-box models based on machine learning have robust complex object simulation performance. In this paper, five common machine learning methods are applied to establish running-in modeling performance based on surface morphology parameters. The support vector machine has the best model performance. The change law of the surface morphology parameters is obtained based on model testing, and the surface morphology optimization is explored. When better oil storage capacity is required, the recommendation is to increase the Sq, Sdq and Sk surface parameter values while setting medium Sdc and Sdr surface parameter values. When a lower coefficient of friction (COF) is required, Sdc and Sdr should be decreased, and Sq and Sdq should be increased. When better support performance is required, Sdc, Sdq, and Sdr should be increased. This article provides a solution to establish a link between surface design and functional performance in the steady wear stage, further filling the gap in quality monitoring of lifecycles.


Author(s):  
Siyan Yang ◽  
Tingting Hao ◽  
Mucan Liu ◽  
Xingtong Yu ◽  
Xuehu Ma

Abstract Droplets bouncing off cold surfaces before being frozen is one way to achieve anti-icing, in which process superhydrophobic surfaces have been proven to play an important role. By using template-assisted method, three types of copper nanowired superhydrophobic surfaces (NSHSs) with mainly two morphologies (aggregated and upright) are fabricated. CuO nanograssed superhydrophobic surface (SHS) and copper smooth hydrophobic surface (HS) are also fabricated as a comparison. Compared with smooth HS and nanograssed SHS, all NSHSs exhibit better performance in repelling impacting droplet. In detail, on three types of NSHSs with temperatures ranging from 20 °C to −20 °C, impacting droplets can totally rebound. Among the three types, nanowires aggregated most exhibit the best water-repellency performance. The different performances among the five surfaces are due to surface temperature and surface morphology parameters, including micro/nano-size and surface roughness.


Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.


Author(s):  
A. Singh ◽  
A. Dykeman ◽  
J. Jarrelf ◽  
D. C. Villeneuve

Hexachlorobenzene (HCB), a persistent and mobile organochlorine pesticide, occurs in environment. HCB has been shown to be present in human follicular fluid. An objective of the present report, which is part of a comprehensive study on reproductive toxicity of HCB, was to determine the cytologic effects of the compound on ovarian follicles in a primate model.Materials and Methods. Eight Cynomolgus monkeys were housed under controlled conditions at Animal facility of Health and Welfare, Ottawa. Animals were orally administered gelatin capsules containing HCB mixed with glucose in daily dosages of 0.0 or 10 mg/kg b.w. for 90 days; the former was the control group. On the menstrual period following completion of dosing, the monkeys underwent an induction cycle of superovulation. At necropsy, one-half of an ovary from each animal was diced into ca. 2- to 3-mm cubed specimens that were fixed by immersion in 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.3). Subsequent procedures followed to obtain thin sections that were examined in a Hitachi H-7000 electron microscope have been described earlier.


Author(s):  
Li C.L. ◽  
Chew E.C. ◽  
Huang D.P. ◽  
Ho H.C. ◽  
Mak L.S. ◽  
...  

An epithelial cell line, NPC/HK1, has recently been successfully established from a nasopharyngeal carcinoma of the moderately to well differentiated squamous type. The present communication reports on the surface morphology of the NPC/HK1 cells in culture.


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