Study of the possibility to measure the root-mean-square roughness of a shaded rough surface

2000 ◽  
Vol 89 (3) ◽  
pp. 397-401 ◽  
Author(s):  
V. Ya. Mendeleev
Keyword(s):  
Rough Surface ◽  
Root Mean Square ◽  
Root Mean Square Roughness ◽  
Mean Square

Autocovariance functions, root-mean-square-roughness height, and autocovariance length for rough deposits of copper, silver, and gold

1982 ◽  
Vol 25 (4) ◽  
pp. 2315-2323 ◽  
Author(s):  
G. Rasigni ◽  
F. Varnier ◽  
M. Rasigni ◽  
J. P. Palmari ◽  
A. Llebaria
Keyword(s):  
Root Mean Square ◽  
Roughness Height ◽  
Root Mean Square Roughness ◽  
Mean Square

The Quantification of Microwear on Chipped Stone Tools: Assessing the Effectiveness of Root Mean Square Roughness (Rq)

2008 ◽  
Vol 33 (2) ◽  
pp. 173-189 ◽  
Author(s):  
W. James Stemp ◽  
Ben E. Childs ◽  
Samuel Vionnet ◽  
Christopher A. Brown
Keyword(s):  
Root Mean Square ◽  
Stone Tools ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Chipped Stone

Direct numerical simulation of turbulence over systematically varied irregular rough surfaces

2019 ◽  
Vol 862 ◽  
pp. 781-815 ◽  
Author(s):  
Y. Kuwata ◽  
Y. Kawaguchi
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Root Mean Square ◽  
Drag Force ◽  
Rough Surfaces ◽  
Skin Friction Coefficient ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Mean Velocity ◽  
Navier Stokes Equation

Lattice Boltzmann direct numerical simulation of turbulent open-channel flows over randomly distributed hemispheres at $Re_{\unicode[STIX]{x1D70F}}=600$ is carried out to reveal the influence of roughness parameters related to a probability density function of rough-surface elevation on turbulence by analysing the spatial and Reynolds- (double-) averaged Navier–Stokes equation. This study specifically concentrates on the influence of the root-mean-square roughness and the skewness, and profiles of turbulence statistics are compared by introducing an effective wall-normal distance defined as a wall-normal integrated plane porosity. The effective distance can completely collapse the total shear stress outside the roughness sublayer, and thus the similarity of the streamwise mean velocity is clearer by introducing the effective distance. In order to examine the influence of the root-mean-square roughness and the skewness on dynamical effects that contribute to an increase in the skin friction coefficient, the triple-integrated double-averaged Navier–Stokes equation is analysed. The main contributors to the skin friction coefficient are found to be turbulence and drag force. The turbulence contribution increases with the root-mean-square roughness and/or the skewness. The drag force contribution, on the other hand, increases in particular with the root-mean-square roughness whereas an increase in the skewness does not increase the drag force contribution because it does not necessarily increase the surface area of the roughness elements. The contribution of the mean velocity dispersion induced by spatial inhomogeneity of the rough surfaces substantially increases with the root-mean-square roughness. A linear correlation is confirmed between the root-mean-square roughness and the equivalent roughness while the equivalent roughness monotonically increases with the skewness. A new correlation function based on the root-mean-square roughness and the skewness is developed with the available experimental and direct numerical simulation data, and it is confirmed that the developed correlation reasonably predicts the equivalent roughness of various types of real rough surfaces.

scholarly journals Manufacture of Highly Transparent and Hazy Cellulose Nanofibril Films via Coating TEMPO-Oxidized Wood Fibers

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 107 ◽  
Author(s):  
Weisheng Yang ◽  
Liang Jiao ◽  
Wei Liu ◽  
Hongqi Dai
Keyword(s):  
Root Mean Square ◽  
Low Cost ◽  
Inorganic Nanoparticles ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Cellulose Nanofibril ◽  
Wood Fibers ◽  
Excellent Thermal Stability ◽  
Blending Method ◽  
Coating Method

Traditionally, inorganic nanoparticles (SiO2, TiO2) have been utilized to tune the optical haze of optoelectronic devices. However, restricted to complex and costly processes for incorporating these nanoparticles, a simple and low-cost approach becomes particularly important. In this work, a simple, effective, and low-cost method was proposed to improve optical haze of transparent cellulose nanofibril films by directly depositing micro-sized 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized wood fibers (“coating” method). The obtained films had a high total transmittance of 85% and a high haze of 62%. The film samples also showed a high tensile strength of 80 MPa and excellent thermal stability. Dual sides of the obtained films had different microstructures: one side was extremely smooth (root-mean-square roughness of 6.25 nm), and the other was extremely rough (root-mean-square roughness of 918 nm). As a reference, micro-sized TEMPO-oxidized wood fibers and cellulose nanofibrils were mixed to form a transparent and hazy film (“blending” method). These results show that hazy transparent films prepared using the “coating” method exhibit superior application performances than films prepared using the “blending” method.

Simulation on Composite Backscattering from Rough Surface with Target above it

2012 ◽  
Vol 490-495 ◽  
pp. 603-607
Author(s):  
Wei Tian ◽  
Xin Cheng Ren
Keyword(s):  
Rough Surface ◽  
Root Mean Square ◽  
Cross Section ◽  
Correlation Length ◽  
Rectangular Cross Section ◽  
Mean Square ◽  
Method Of Moment ◽  
Backscattering Coefficient ◽  
One Dimensional ◽  
Surface Fluctuation

One-dimensional Gaussion rough surface is simulated and employed by Monte Carlo Method, the composite backscattering from one-dimensional Gaussion rough surface with rectangular cross-section column above it is studied using Method of Moment. The curves of composite backscattering coefficient with scattering angle and frequency of incident wave are simulated by numerical calculation, the influence of the root mean square and the correlation length of rough surface fluctuation, the height between the center of the rectangular cross-section column and the rough surface, the length and the width of the rectangular cross-section column is discussed. The characteristic of the composite back-scatting from one-dimensional Gaussion rough surface with a rectangular cross-section column above it is obtained. The results show that the influences of the root mean square and the correlation length of rough surface fluctuation, the height between the center of the rectangular cross-section column and the rough surface, the width of the rectangular cross-section column on the composite backscattering coefficients are obvious while the influences of the length of the rectangular cross-section column on the complex backscattering coefficient is less.

Morphological Character and Statistical Property of Random Surface of ZnO Thin Film Prepared by RF Magnetron Sputtering

2010 ◽  
Vol 663-665 ◽  
pp. 1159-1162
Author(s):  
Ning Yu Zhang ◽  
Qing Song Huo ◽  
Li Xin Han ◽  
Gang Fu ◽  
Jun Qing Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Root Mean Square ◽  
Gaussian Function ◽  
Gaussian Model ◽  
Film Surface ◽  
Root Mean Square Roughness ◽  
Zno Thin Film ◽  
Mean Square ◽  
Auto Correlation

A method for characterizing the morphology property of ZnO film surface with Gaussian correlation is investigated. The parameters of root-mean-square roughness w and lateral correlation lengthξare introduced in Gaussian model to describe the correlation properties of the random film surfaces. In the experimental performance, ZnO thin films are grown on quartz glass and silicon substrates by the reactive radio-frequency magnetron sputtering method under different deposition pressure. The surface morphologies of the film surface are scanned by an atomic force microscopy. The height auto-correlation functions and root-mean-square roughness are obtained by using the numerical calculus method. Carried on the fitting with the Gaussian function to the height auto-correlation function data, the lateral correlation lengths are extracted to describe the statistical properties of ZnO thin film in mathematics with other parameters.

scholarly journals Damage-Free Photo-Assisted Cryogenic Etching of GaN as Evidenced by Reduction of Yellow Luminescence

1999 ◽  
Vol 4 (S1) ◽  
pp. 914-919 ◽  
Author(s):  
J. T. Hsieh ◽  
J. M. Hwang ◽  
H. L. Hwang ◽  
W. H. Hung
Keyword(s):  
Surface Morphology ◽  
Root Mean Square ◽  
Low Temperatures ◽  
Etch Rate ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Photoluminescence Spectra ◽  
Yellow Luminescence ◽  
Etching Technique ◽  
193 Nm

Damage-free etching of GaN by Cl2, assisted by an ArF (193 nm) excimer laser, is demonstrated. At low temperatures, photo-assisted etching can provide a better etch rate and largely improve the surface morphology and quality. AFM results show that the etched GaN surface is obtained with a root-mean-square roughness of 1.7 nm. As compared with the photoluminescence spectra of photoelectrochemical wet etched GaN, the photo-assisted cryogenic etching is proved to be a damage-free dry etching technique.

scholarly journals ROUGHNESS AND STRUCTURE OF InGaAsN THIN FILMS ON Si

2021 ◽  
pp. 106-114
Author(s):  
Олег Васильевич Девицкий
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Root Mean Square ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Force Microscopy ◽  
Si Substrates ◽  
Nitrogen Mixture

Методом импульсного лазерного напыления в атмосфере аргоно-азотной газовой смеси из мишени InGaAs впервые были получены тонкие пленки InGaAsN на подложках GaAs и Si. Мишень lnGaAs формировалась методом одноосного прессования из порошков GaAs и lnAs. Методами атомно силовой микроскопии и рентгеновской дифракции исследованы морфология поверхности и структура данных тонких пленок. Показано, что пленки InGaAsN на Si имеют средний размер кристалла 0,93 нм, а пленки и InGaAsN на GaAs - 0,99 нм. Определено, что уменьшение давления аргоно-азотной смеси при импульсном лазерном напылении тонких пленок InGaAsN на подложках GaAs и Si приводит к снижению значения среднеквадратичной шероховатости поверхности. Наименьшую среднеквадратическую шероховатость равную 0,25 нм имела тонкая пленка InGaAsN на подложке GaAs, полученная в вакууме, наибольшую среднеквадратическую шероховатость имела тонкая пленка InGaAsN на подложке Si, полученная при давления аргоно-азотной смеси от 10 Па - 19,37 нм. By the method of pulsed laser deposition in atmosphere of an argon-nitrogen gas mixture, for the first time thin InGaAsN films on GaAs and Si substrates were obtained from the InGaAs target. The InGaAs target was formed by uniaxial pressing from GaAs and InAs powders. The surface morphology and structure of these thin films are studied by atomic force microscopy and X-ray diffraction. It is shown that InGaAsN films on Si have an average crystal size of 0,93 nm, and InGaAsN films on GaAs of 0,99 nm. It is determined that a decrease in the pressure of an argon-nitrogen mixture during pulsed laser deposition of thin InGaAsN films on GaAs and Si substrates leads to a decrease in the value of the root- mean-square roughness of the surface. The smallest root-mean-square roughness equal to 0,25 nm had a thin InGaAsN film on a GaAs substrate obtained in vacuum, the largest root-mean- square roughness of 19,37 nm had a thin InGaAsN film on a Si substrate obtained at the argon-nitrogen mixture pressure of 10 Pa -.

scholarly journals Elucidation of contact state on various rough surfaces via highly robust colorimetric optical interferometry

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Tatsunori Tomota ◽  
Mamoru Tohyama ◽  
Kazuyuki Yagi
Keyword(s):  
Film Thickness ◽  
Root Mean Square ◽  
Contact Area ◽  
Thickness Distribution ◽  
Optical Interferometry ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Test Pieces ◽  
Static Contact ◽  
Nominal Contact Area

AbstractIn this study, we developed and practiced colorimetric optical interferometry for the direct observation of contact states to clarify contact phenomena. We theoretically demonstrated that the effect of roughness diffuse reflection could be neglected using interferometric light intensity according to the relationship between the optical film thickness and hue. Then, we measured the static contact surfaces of spherical test pieces of different root mean square roughnesses. Results indicate that the nominal contact area is significantly larger than that obtained from the Hertzian theory of smooth contact as the surface roughness increases. The contact film thickness on the nominal contact area increases almost in proportion to the root mean square roughness. Our experiment supports the validity of the contact theory and contact simulation with very small roughnesses, which have been difficult to verify experimentally. The advantage of this measurement is that it can simultaneously capture the macroscopic contact area and microscopic film thickness distribution, which is expected to further expand the range of application.

The Generating Mechanism of Surface Roughness by Random Cutting Edges

1978 ◽  
Vol 20 (4) ◽  
pp. 197-200
Author(s):  
M. Hasegawa ◽  
T. Tsukizoe
Keyword(s):  
Surface Roughness ◽  
Root Mean Square ◽  
Statistical Approach ◽  
Ground Surface ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Two Dimensional ◽  
Dimensional Distribution

This paper describes a statistical approach for predicting the generating mechanism of the surface roughness produced by random cutting edges. The two-dimensional distribution of the generated surface roughness is derived by considering the distribution of the maxima of the cutting edges. The method is used to determine the root-mean-square roughness of the ground surface.

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