A method for measuring the surface roughness factor of metals

1972 ◽  
Vol 12 (5) ◽  
pp. 463-468 ◽  
Author(s):  
M. Pražák ◽  
B. Eremiás
1997 ◽  
Vol 63 (607) ◽  
pp. 643-649 ◽  
Author(s):  
Sohji SAKATA ◽  
Toshio HATSUDA ◽  
Akihiro KAWABE ◽  
Hiromitsu OHNO ◽  
Yuko HIROHATA ◽  
...  

Shinku ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 204-207
Author(s):  
Yasushi MAKABE ◽  
Yuko HIROHATA ◽  
Tomoaki HINO ◽  
Toshiro YAMASHINA

1981 ◽  
Vol 103 ◽  
pp. 445-449 ◽  
Author(s):  
S. Maeda ◽  
M. Mohri ◽  
M. Hashiba ◽  
T. Yamashina ◽  
M. Kaminsky

2003 ◽  
Vol 82 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Han-Jun Oh ◽  
Gyeong-Su Park ◽  
Jung-Gu Kim ◽  
Yongsoo Jeong ◽  
Choong-Soo Chi

2008 ◽  
Vol 373-374 ◽  
pp. 184-187
Author(s):  
Ying Chun Shan ◽  
Jiu Jun Xu ◽  
Xiao Dong He ◽  
Ming Wei Li

A 2D kinetic Monte Carlo (KMC) simulation has been applied to study the microstructure of Ni-Cr film deposited by physical vapor deposition (PVD) for variable incident angle. In the KMC method, two phenomena were incorporated: adatom-surface collision and adatom diffusion, the interaction between atoms was described by embedded atom method and jumping energy was calculated by molecular statics calculations, initial location of adatom was located by Momentum Scheme. The results reveal that there exists critical incident angle, which is 35˚ for Ni-Cr thin film. When incident angle is less than 35˚, incident angle have less affect on surface roughness factor and packing density, compact films with smooth surface are obtained, their surface roughness factor is bellow 1.12 and packing density is more than 99.6%. However, when incident angle is more than 35˚, surface roughness factor increases quickly and packing density decreases sharply with incident angle increasing: surface roughness factor increase to 1.5 and 2.3 for incident angle of 45˚ and 60˚ respectively, packing density is below 99% and 96% accordingly. Which reveal that the self-shadowing effect emphasizes with incident angle increasing when the incident angle is more than 35˚.


Author(s):  
Dhairyasheel Deshmukh ◽  
M. Hamid Siddique ◽  
Abdus Samad

An electric submersible pump (ESP) is a multistage centrifugal pump widely used in the petroleum industry to transport wellbore fluids to the surface. For a turbulent flow through a pump, the surface roughness plays a vital role as it causes flow separation and increases boundary layer momentum loss. In the present work, a 3D numerical analysis by solving a Reynolds-averaged Navier-Stokes equation with k-ω SST turbulence model for wall bounded steady incompressible flow through a pump was carried out. The geometry was meshed and validated numerically with the experimental data available in the literature. At the design and off-design conditions, the simulations were conducted to study the effect of roughness and its dependence on Reynolds number of the flow. The performance of the pump was compared for a nondimensional roughness factor (K). A hydraulically smooth surface gives a maximum head. A drop in head observed up to the critical surface roughness (K = 0.1), and the head further rises for K > 0.1. The effect of roughness factor increases with increase in Reynolds number.


2003 ◽  
Vol 40 (5) ◽  
pp. 1039-1047 ◽  
Author(s):  
Yung-Shan Hong ◽  
Cho-Sen Wu ◽  
Shang-Heng Yang

Pullout tests on single and double soil nails were conducted in a model sandbox. The test parameters included variations in the surface roughness, the ratio of nail length to nail diameter, the overburden pressure, and the distance between two nails. The characteristic of a single asperity, the asperity number per unit length, and the ratio of the thread depth to the soil particle size were used to define the surface roughness factor. The test results showed that the apparent friction coefficients at the soil–nail interface were dependent upon the surface roughness of the nail. Group efficiency was used to evaluate the effectiveness of a nail when installed within a group. The test results showed that the group efficiency of a double-nail system was dependent upon the surface roughness factor and has a linear relationship with the nail distance until 100% efficiency is reached. The minimum required distance for 100% efficiency also varied with the surface roughness factor.Key words: apparent friction coefficient, group efficiency, pullout test, surface roughness factor.


2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Mohammad Abdullah Al-Rawi

"act Woodruff and siddoway, 1965, established an equation for the estimation of soil Loss by wind erosion called Wind Erosion Equation (WEQ); solution of this equation gives the maximum amount of wind erosion under certain field conditions and is considered evidence in identifying the necessary methods for treating wind erosion in those conditions (Eltaif et al.,1991). This study aims to find out the extent to which climate change in the Samawah region of southern Iraq and Baghdad in central Iraq over a period of 34 years has affected values of soil losing by wind erosion using equation of (woodruff and siddoway, 1965) and effectiveness of this changes in soil surface roughness factor in reducing or increasing these loss. Two sites were selected located within central and southern regions of Iraq, one in Al-Jadiriya area in Baghdad governorate and the other in Samawah area in Al-Muthanna governorate. The results showed that estimated soil losing for years (1980-2013) in Al-Jadiriya decrease annually by 10-30 kg.hec.-1.year-1, while samawah increase by 240-760 kg.hec.-1.year-1. The effect of surface roughness factor was significant in reducing soil loss during period of study. Roughness factor for ridge (0.5) has reduced soil losing by 2.6 times compared to non-ridge soils (1).The ratio in semi-bridge soil (0.75) was 65%. This is due to the impact of bridge in reducing wind speed and reducing its erosivity. The general direction of soil loss indicates decrease in Al-Jadiriya area and increase in Samawah area with the case of fluctuation in soil loss between high and low of general direction line due to climate factor (C) in general equation of soil loss and it reflects ability of wind erosion, so decreased when wet conditions improved, by increased rainfall, reduced evaporation and increasing when dry conditions dominate Corresponding author: E-mail( [email protected] ) All rights reserved AlMuthanna University"


Author(s):  
I. H. Musselman ◽  
R.-T. Chen ◽  
P. E. Russell

Scanning tunneling microscopy (STM) has been used to characterize the surface roughness of nonlinear optical (NLO) polymers. A review of STM of polymer surfaces is included in this volume. The NLO polymers are instrumental in the development of electrooptical waveguide devices, the most fundamental of which is the modulator. The most common modulator design is the Mach Zehnder interferometer, in which the input light is split into two legs and then recombined into a common output within the two dimensional waveguide. A π phase retardation, resulting in total light extinction at the output of the interferometer, can be achieved by changing the refractive index of one leg with respect to the other using the electrooptic effect. For best device performance, it is essential that the NLO polymer exhibit minimal surface roughness in order to reduce light scattering. Scanning tunneling microscopy, with its high lateral and vertical resolution, is capable of quantifying the NLO polymer surface roughness induced by processing. Results are presented below in which STM was used to measure the surface roughness of films produced by spin-coating NLO-active polymers onto silicon substrates.


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