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Littérature scientifique sur le sujet « Surface roughne »

Auteur : Grafiati

Publié le 9 mars 2023

Mis à jour le 10 mars 2023

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Articles de revues sur le sujet "Surface roughne"

Yun, Yong Il, Il Young Park et Seung Jin Song. « Performance Degradation due to Blade Surface Roughness in a Single-Stage Axial Turbine ». Journal of Turbomachinery 127, n^o 1 (1 janvier 2005) : 137–43. http://dx.doi.org/10.1115/1.1811097.

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Turbine blades experience significant surface degradation with service. Previous studies indicate that an order-of-magnitude or greater increase in roughness height is typical, and these elevated levels of surface roughness significantly influence turbine efficiency and heat transfer. This paper presents measurement and a mean-line analysis of turbine efficiency reduction due to blade surface roughness. Performance tests have been conducted in a low-speed, single-stage, axial flow turbine with roughened blades. Sheets of sandpaper with equivalent sandgrain roughnesses of 106 and 400 μm have been used to roughen the blades. The roughness heights correspond to foreign deposits on real turbine blades measured by Bons et al. [1]. In the transitionally rough regime (106 μm), normalized efficiency decreases by approximately 4% with either roughened stator or roughened rotor and by 8% with roughness on both the stator and rotor blades. In the fully rough regime (400 μm), normalized efficiency decreases by 2% with roughness on the pressure side and by 6% with roughness on the suction side. Also, the normalized efficiency decreases by 11% with roughness only on stator vanes, 8% with roughness only on rotor blades, and 19% with roughness on both the stator and rotor blades.

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Craig, Michael, Jay Raval, Bruce Tai, Albert Patterson et Wayne Hung. « Effect of Channel Roughness on Micro-Droplet Distribution in Internal Minimum Quantity Lubrication ». Dynamics 2, n^o 4 (14 octobre 2022) : 336–55. http://dx.doi.org/10.3390/dynamics2040019.

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This research studied the effect of channel roughness on micro-droplet distributions in internal minimum quantity lubrication for effective machining. Mixtures of different oils and air were flown though internal channels with simulated different roughness: as fabricated, partially threaded, and fully threaded. The airborne droplets were collected, analyzed, and compared with simulated results by computational fluid dynamics. For low-viscous lubricant, the rough channel surface helped to break large droplets in the boundary layer into smaller droplets and reintroduce them into the main downstream flow. The opposite trend was found for the higher viscous lubricant. The study also performed chemical etching to roughen selected surfaces of carbide cutting tools. The synergy of hand and ultrasonic agitation successfully roughened a carbide surface within twelve minutes. Scanning electron microscopy examination showed deep etching that removed all grinding marks on a WC–Co cutting tool surface.

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Kheur, Mohit, Tabrez Lakha, Saleha Shaikh, Supriya Kheur, Batul Qamri, Lee Wan Zhen, Nadin Al-Haj Husain et Mutlu Özcan. « A Comparative Study on Simulated Chairside Grinding and Polishing of Monolithic Zirconia ». Materials 15, n^o 6 (16 mars 2022) : 2202. http://dx.doi.org/10.3390/ma15062202.

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This study evaluated the effects of different simulated chairside grinding and polishing protocols on the physical and mechanical properties of surface roughness, hardness, and flexural strength of monolithic zirconia. Sintered monolithic zirconia specimens (15 mm × 3 mm × 3 mm) were abraded using three different burs: diamond bur, modified diamond bur (zirconia specified), and tungsten carbide bur, along with a group of unprepared specimens that served as a control group. The study was divided into two phases, Phase 1 and Phase 2. Surface roughness, surface hardness, and flexural strength were assessed before and after the grinding procedure to determine the ‘best test group’ in Phase 1. The best abrasive agent was selected for Phase 2 of the study. The specimens in Phase 2 underwent grinding with the best abrasive agent selected. Following the grinding, the specimens were then polished using commercially available diamond polishing paste, a porcelain polishing kit, and an indigenously developed low-temperature sintered zirconia slurry. The physical and mechanical properties were again assessed. Results were analyzed using one-way ANOVA test. Specimens were observed under scanning electron microscopy (SEM) and X-ray diffraction (XRD) for their microstructure and crystalline phases, respectively. Grinding with diamond burs did not weaken zirconia (p > 0.05) but produced rougher surfaces than the control group (p < 0.05). Tungsten carbide burs did not significantly roughen the zirconia surface. However, specimens ground by tungsten carbide burs had a significantly reduced mean flexural strength (p < 0.05) and SEM revealed fine surface cracks. Phase transformation was not detected by XRD. Polishing with commercially available polishing agents, however, restored the surface roughness levels to the control group. Dental monolithic zirconia ground with tungsten carbide burs had a significantly reduced flexural strength and a smooth but defective surface. However, grinding with diamond burs roughened the zirconia surface. These defects may be reduced by polishing with commercially available polishing agents. The use of tungsten carbide burs for grinding dental zirconia should not be advocated. Grinding with diamond abrasives does not weaken zirconia but requires further polishing with commercially available polishing agents.

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Wang, Jun, Jose Antonio Sánchez, Borja Izquierdo et Izaro Ayesta. « Influence of AISI D2 Workpiece Roughness on Heat Partition and Plasma Channel Radius in the WEDM Process ». Metals 10, n^o 10 (12 octobre 2020) : 1360. http://dx.doi.org/10.3390/met10101360.

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As an important advanced machining process, in Wire Electrical Discharge Machining (WEDM) certain fundamental issues remain need to be studied in-depth, such as the effect of part surface roughness on heat transfer mechanisms. In the WEDM process, roughing cut wire goes into the workpiece to do the first shaping and in trim cut the wire sweeps on the outer surface to improve the surface roughness. In both of these two cases, the generation of sparks depends on the passing surface roughness. Therefore, with AISI D2 material and brass wire, this paper presents a study of the influence of part surface roughness on heat partition and the radius of the plasma channel in the WEDM process. Through extensive single discharge experiments, it is shown that the removal capacity per discharge can increase if the discharge occurs on a smoother surface. A Finite Element thermal model was then used for inverse fitting of the values of heat partition and radius of the plasma channel. These parameters completely define the characteristics of the heat conduction problem. The results indicate a strong correlation between an increase in heat partition ratio and a decrease in part surface roughness. The values of plasma channel radius show an increase in this value when discharging on rougher surfaces. It means that with the increasing of plasma channel radius, the heat source goes into the workpiece more dispersed. In the case of rougher surface, although the there is more area that affected by the heat source, finally the temperature of most area cannot reach to the melting point and it causes the smaller crater radius and volume, while the metal removal rate decreases. These results contribute towards a more complete understanding of the influence of surface roughness to the spark occurring.

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Mulleners, K., P. Gilge et S. Hohenstein. « Impact of Surface Roughness on the Turbulent Wake Flow of a Turbine Blade ». Journal of Aerodynamics 2014 (30 décembre 2014) : 1–9. http://dx.doi.org/10.1155/2014/458757.

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Roughened aeroengine blade surfaces lead to increased friction losses and reduced efficiency of the individual blades. The surface roughness also affects the wake flow of the blade and thus the inflow conditions for the subsequent compressor or turbine stage. To investigate the impact of surface roughness on a turbulent blade wake, we conducted velocity field measurements by means of stereo particle image velocimetry in the wake of a roughened turbine blade in a linear cascade wind tunnel. The turbine blade was roughened at different chordwise locations. The influence of the chordwise location of the added surface roughness was examined by comparing their impact on the width and depth of the wake and, the positions and distribution of vortical structures in the wake. Additionally, the friction loss coefficients for different surface roughness positions were estimated directly from the velocity field.

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XIAO, BOQI, YIDAN ZHANG, YAN WANG, GUOPING JIANG, MINGCHAO LIANG, XUBING CHEN et GONGBO LONG. « A FRACTAL MODEL FOR KOZENY–CARMAN CONSTANT AND DIMENSIONLESS PERMEABILITY OF FIBROUS POROUS MEDIA WITH ROUGHENED SURFACES ». Fractals 27, n^o 07 (novembre 2019) : 1950116. http://dx.doi.org/10.1142/s0218348x19501160.

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In this paper, fluid transport through fibrous porous media is studied by the fractal theory with a focus on the effect of surface roughness of capillaries. A fractal model for Kozeny–Carman (KC) constant and dimensionless permeability of fibrous porous media with roughened surfaces is derived. The determined KC constant and dimensionless permeability of fibrous porous media with roughened surfaces are in good agreement with available experimental data and existing models reported in the literature. It is found that the KC constant of fibrous porous media with roughened surfaces increases with the increase of relative roughness, porosity, area fractal dimension of pore and tortuosity fractal dimension, respectively. Besides, it is seen that the dimensionless permeability of fibrous porous media with roughened surfaces decreases with increasing relative roughness and tortuosity fractal dimension. However, it is observed that the dimensionless permeability of fibrous porous media with roughened surfaces increases with porosity. With the proposed fractal model, the physical mechanisms of fluids transport through fibrous porous media are better elucidated.

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Jemat, Afida, Mariyam Jameelah Ghazali, Masfueh Razali et Yuichi Otsuka. « Effects of Surface Treatment on Titanium Alloys Substrate by Acid Etching for Dental Implant ». Materials Science Forum 819 (juin 2015) : 347–52. http://dx.doi.org/10.4028/www.scientific.net/msf.819.347.

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Many studies were carried out to investigate the ability of titanium alloys for dental implant. Surface treatment is one of the famous methods to increase the titanium surface properties. The purpose of this paper is to investigate the effects of acid etching on the surface topography and roughness of titanium alloys (Ti6Al4V ASTM 1472-99). Acid etchings were carried out by using different type of acids with same time exposures. All etched surface were characterized by using an X-ray diffraction (XRD), a scanning electron microscope (SEM) and a roughness tester. Acid etched and pure surface were comparatively analysed. Results obtained show that the type of acids influenced the surface topography as well as roughness properties. The microstructure of the surface is highly modified after acid etching. Further we can confirm that, the experimental etched titanium alloys had features of a roughened surface with micro-roughness. In general, the experimental surface (0.137 μm – 3.986 μm) was significantly rougher than control surface (0.124 μm).

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Bennett, Jean M. « Surface Roughness and Scattering ». Proceedings of The Manufacturing & ; Machine Tool Conference 2004.5 (2004) : 15–16. http://dx.doi.org/10.1299/jsmemmt.2004.5.15.

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Alaskari, Ayman M., Abdulaziz I. Albannai, Meshal Y. Alawadhi, Abdulkareem S. Aloraier, Tatiana Liptakova et Abdullah A. Alazemi. « Surface Evaluation of a Multi-Pass Flexible Magnetic Burnishing Brush for Rough and Soft Ground 60/40 Brass ». Materials 13, n^o 19 (8 octobre 2020) : 4465. http://dx.doi.org/10.3390/ma13194465.

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Burnishing is an advanced finishing process that produces higher-quality surfaces with better hardness and roughness than conventional finishing processes. Herein, a flexible magnetic burnishing brush comprising stainless steel pins under permanent magnet poles was used to investigate the influence of multiple passes and directions on the produced surface of soft and rough ground prepared brass. In total, five different samples were burnished on each of the two brass samples prepared. Four samples were processed in the same direction for up to four passes and the fifth sample was processed with two passes in the opposite direction. Results indicate that there was approximately a 30% increase in hardness and an 83% increase in microroughness for rougher-surface brass samples. For smoothly prepared surfaces, there was approximately a 14% increase in hardness and a 35% increase in microroughness. In the same direction of multi-pass burnishing, increasing the number of passes negatively affected surface roughness; for rougher surfaces, the surface hardness reduced and process uniformity increased owing to surface over-hardening and flaking mechanisms, and for smoother surfaces, the hardness, roughness, and process non-uniformity increased with the number of passes owing to repeated surface deformation at some locations and high flaking at other locations. Compared to single-pass burnishing, wherein the surface roughness and microhardness showed almost no change with high process uniformity, in burnishing with two opposite-direction passes, the produced surface exhibited better surface roughness, process uniformity, and microhardness improvements owing to a reverse strain mechanism. Hence, opposite burnishing passes are recommended.

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Taslim, M. E., L. Setayeshgar et S. D. Spring. « An Experimental Evaluation of Advanced Leading Edge Impingement Cooling Concepts ». Journal of Turbomachinery 123, n^o 1 (1 février 2000) : 147–53. http://dx.doi.org/10.1115/1.1331537.

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The main objective of this experimental investigation was to measure the convective heat transfer coefficient of impingement for different target wall roughness geometries of an airfoil leading edge, for jet to wall spacings and exit flow schemes. Available data in the open literature apply mostly to impingement on flat or curved smooth surfaces. This investigation covered two relatively new features in blade leading-edge cooling concepts: curved and roughened target surfaces. Experimental results are presented for four test sections representing the leading-edge cooling cavity with cross-over jets impinging on: (1) a smooth wall, (2) a wall with high surface roughness, (3) a wall roughened with conical bumps, and (4) a wall roughened with tapered radial ribs. The tests were run for two supply and three exit flow arrangements and a range of jet Reynolds numbers. The major conclusions of this study were: (a) There is a heat transfer enhancement benefit in roughening the target surface; (b) while the surface roughness increases the impingement heat transfer coefficient, the driving factor in heat transfer enhancement is the increase in surface area; (c) among the four tested surface geometries, the conical bumps produced the highest heat transfer enhancement.

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Thèses sur le sujet "Surface roughne"

COLOMBO, ANNALISA. « Synthesis and characterization of TiO2 polymeric nanocomposites with tailorable optical properties ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2012. http://hdl.handle.net/10281/28632.

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Main aim of this work was the fabrication and characterization of polymeric TiO2 hybrid nanocomposites. When dispersed at the nanoscale level, TiO2 can tune the optical properties of the polymeric matrix, such as the UV absorption and the increase of refractive index, preserving the transparency in the visible and the flexibility of the polymer. TiO2 nanopaticles were modified on the surface with different molecules; they were then dispersed in MMA and polymerized in bulk, in order to obtain optically transparent TiO2/Poly-methylmethacrylate (PMMA) sheets. The application of these objects was in the solid-state lighting field, where the nanoparticles play the role of light diffusers according to Rayleigh Scattering. Films based on poly 2-ethyl-2-oxazoline (PEOX) and TiO2 nanoparticles with concentrations up to 44 % in weight were also prepared by casting from water solutions. Nanocomposites films remained highly transparent in the visible, and absorbed UV radiation up to the proximity of the visible range. The refractive indices of the films raised from about 1.52 to 1.65 with increasing of TiO2 concentration. The good optical properties and the solubility in water of these materials could allow their application in the paint and coating industry, and in the field of conservation of cultural heritage as consolidants or varnishes of paintings.

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Vandadi, Aref. « Optimization of Superhydrophobic Surfaces to Maintain Continuous Dropwise Condensation ». Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500016/.

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In the past decade, the condensation on superhydrophobic surfaces has been investigated abundantly to achieve dropwise condensation. There is not a specific approach in choosing the size of the roughness of the superhydrophobic surfaces and it was mostly selected arbitrarily to investigate the behavior of condensates on these surfaces. In this research, we are optimizing the size of the roughness of the superhydrophobic surface in order to achieve dropwise condensation. By minimizing the resistances toward the transition of the tails of droplets from the cavities of the roughness to the top of the roughness, the size of the roughness is optimized. It is shown that by decreasing the size of the roughness of the superhydrophobic surface, the resistances toward the transition of the tails of droplets from Wenzel state to Cassie state decrease and consequently dropwise condensation becomes more likely.

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Thoreson, Erik J. « From nanoscale to macroscale using the atomic force microscope to quantify the role of few-asperity contacts in adhesion ». Link to electronic dissertation, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-010906-204218/.

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Ștefan, Gheorghiu. « Standard and nonstandard roughness - consequences for the physics of self-affine surfaces / ». free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9988664.

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Berry, Elizabeth. « Fabrication of multiscale random rough surfaces with prescribed surface statistics ». Thesis, Imperial College London, 1986. http://hdl.handle.net/10044/1/37944.

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Yang, Hongta. « Fundamentals, preparation, and characterization of superhydrophobic wood fiber products ». Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24796.

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Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Yulin Deng; Committee Member: Jeffery S. Hsieh; Committee Member: Sujit Banerjee; Committee Member: Zhong Lin Wang.

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Zhang, Yilei. « The effect of surface roughness parameters on contact and wettability of solid surfaces ». [Ames, Iowa : Iowa State University], 2007.

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Mamo, Andrew Benedict 1982. « Surface roughness of Mars ». Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32744.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2004.
Includes bibliographical references (p. 35-36).
In this thesis, I created an algorithm to compensate for the saturation of data collected by the Mars Orbiter Laser Altimeter (MOLA). Saturation of the energy measurements had made it impossible to measure surface roughness at 100 m length scales. By calculating the returned energy, the problem of saturation can be avoided. This algorithm was applied to MOLA data across the Martian surface to create an estimate of surface roughness across the planet. The method calculates pulse spreading from returned pulse energy using the link equation. The accuracy of the method is limited by the accuracy of albedo measurements. This analysis improved the estimation of surface roughness on Mars. Further improvements could be gained by correcting for the opacity of atmospheric dust as a cause of pulse spreading.
by Andrew Benedict Mamo.
S.B.

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Li, Hongchun. « A study on wear and surface roughness of work roll in cold rolling ». School of Mechanical, Materials and Mechatronic Engineering - Faculty of Engineering, 2008. http://ro.uow.edu.au/theses/125.

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The objective of this study is to improve our understanding of the evolution and tribological behaviour of work roll surfaces in cold rolling because surface deterioration affects the quality of products and the efficiency of production. The cost of rolls is almost 25% of the cost of cold steel production. An experimental Lateral Set-testing (LST) mini-mill was developed to make use of the Gleeble 3500 thermo-mechanical simulator functions to evaluate, for the first time, the roll material surface features, surface roughness, fast Fourier transform (FFT) and Power Spectral Density (PSD) of frequency distribution, after single and multi-pass rolling. A low carbon-steel was prepared for the paired disc and then experiments on disc-to-disc wear were carried out to test surface deterioration and friction. In the laboratory, material imitating an industrial roll was manufactured. One batch contained 4%Cr and another contained 4%Cr plus approximately 0.1% Ti. These materials were compared against each other in the LST and disc-to-disc experiments. Experiments considered a series of parameters, including strip reduction, speed, and lubrication, while the disc-to-disc experiments considered duration of wear, forward and backward slip and load amplitude. The surfaces of the LST roller and disc were evaluated by surface technologies such as Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), and surface profile-meters. Transmission Electron Microscope (TEM) and X-ray diffraction wear properties. Test results from the mini-mill reveal that dominant waviness of the surface roughness still exists on the surface after a single pass of rolling and a 30.5% reduction is a critical reduction level that has a significant influence on the density of power spectrum. A rougher work piece results in a larger power spectrum of the surface profile. It has found that the PSD altitude of the roller surface is significantly affected axially but is more sensitive to its original surface roughness circumferentially. It is distributed in an inverse order to the surface roughness in a high frequency domain. The addition of Ti alters surface deterioration. Lubrication has a significant effect on surfaces containing either 4Cr% or 4%Cr+Ti, affecting surface roughness of rollers containing 4%Cr more significantly. In the disc-to-disc tests, more material was removed in the first 60 minutes from the disc containing Ti than the disc containing only 4%Cr. In general, roll material with 4%Cr+Ti reveals to have better anti-abrasive properties than the roll with only 4%Cr, while lubrication significantly reduced the wear rate and amount of material removed from both materials. The speed of the disc influences the weight loss, ie, the higher the speed the greater the amount of material removed. The slip rate also affects roll wear and weight loss because as the speed increases, so do the slip and loss of weight. The coefficients of friction are between 0.35~0.75 when the contact was dry and 0.06~0.11 when lubrication was applied. Adhesive friction dominated the dry contact while a mixed lubrication regime features friction behaviour when emulsion lubrication was applied. A backward slip of 2% and a forward slip of 1.5% resulted in a different coefficient of friction in dry contact mode although the corresponding torques were similar. The torque and coefficient of friction are found to increase with disc speed in dry contact condition. Lubrication alters the friction of both materials. The coefficient of friction decreases with speed on the disc with added Ti but the effect of load is in the opposite trend, while the disc with 4%Cr was less influenced by speed. The coefficient of friction is more sensitive to load at higher speeds on the disc with 4%Cr than at slower speeds on the disc with Ti added. This indicates that the addition of Ti enhances the tribological behaviour of rollers because the disc with Ti additive is characterised by carbonitrades precipitated in a refined tempered martensitic matrix. Coarse carbides characterise the 4%Cr disc materials. Surface defects of the work rolls, including banding, spalling, marking and welding in a cold strip plant, were investigated. It was found that early failures principally resulted from operational factors and roll material off-specification micro-structure defects rather than wear. It is recommended that different grades materials of the roll and strip with different roughness and hardness to be tested and studied on the evolution and tribological behaviour of roll surfaces in the future.

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Al-Maaitah, Ayman Adnan. « Effect of roughness element on the stability of boundary layers ». Thesis, Virginia Tech, 1986. http://hdl.handle.net/10919/45741.

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The instability of flows around hump and dip imperfections is investigated. The mean flow is calculated using interacting boundary layers, thereby accounting for viscous/inviscid interaction and separation bubbles. Then, the two-dimensional linear instability of this flow is analyzed, and the amplification factors are computed. Results are obtained for several height/width ratios and locations. The theoretical results have been used to correlate the experimental results of Greening and Walker. The observed transition locations are found to correspond to amplification factors varying between 7.4 and 10, consistent with previous results for flat plates. The method accounts for Tollmien-Schlichting waves, the shear layer instability, and their interaction. Separation is found to increase significantly the amplification factor.
Master of Science

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Livres sur le sujet "Surface roughne"

M, Bennett Jean, European Physical Society, European Federation for Applied Optics. et Society of Photo-optical Instrumentation Engineers., dir. Surface measurement and characterization : ECO1 19-21 September, 1988, Hamburg, Federal Republic of Germany. Bellingham, Wash : SPIE--the International Society for Optical Engineering, 1989.

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Wieczorowski, Michał. Wykorzystanie analizy topograficznej w pomiarach nierówności powierzchni. Poznań : Wydawn. Politechniki Poznańskiej, 2000.

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Wieczorowski, Michał. Wykorzystanie analizy topograficznej w pomiarach nierówności powierzchni. Poznań : Wydawn. Politechniki Poznańskiej, 2000.

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Internationales Oberflächenkolloquium (8th 1992 Technische Universität Chemnitz). VIII. Internationales Oberflächenkolloquium : 3. bis 5. Februar 1992 in Chemnitz. Chemnitz : Technische Universität Chemnitz, 1991.

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Internationales Oberflächenkolloquium (7th 1988 Karl-Marx-Stadt, Germany). VII. Internationales Oberflächenkolloquium : 8. bis 10. Februar 1988 in Karl-Marx-Stadt. Sous la direction de Trumpold H, Meier Werner et Technische Universität Karl-Marx-Stadt. Sektion Fertigungsprozess und Fertigungsmittel. Karl-Marx-Stadt : Der Rektor der Technischen Universität Karl-Marx-Stadt, 1988.

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Rising, Trudy L. Is it smooth or rough ? New York, N.Y : Crabtree Pub. Company, 2012.

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Raether, Heinz. Surface Plasmons on Smooth and Rough Surfaces and on Gratings. Berlin, Heidelberg : Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/bfb0048317.

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Raether, H. Surface plasmons on smooth and rough surfaces and on gratings. Berlin a.o. : Springer-Verlag, 1988.

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Raether, H. Surface plasmons on smooth and rough surfaces and on gratings. Berlin : Springer-Verlag, 1988.

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1946-, Wang G. C., et Lu T. M. 1943-, dir. Diffraction from rough surfaces and dynamic growth fronts. Singapore : World Scientific Pub., 1993.

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Chapitres de livres sur le sujet "Surface roughne"

Grohmann, Carlos H., et Henrik Hargitai. « Surface Roughness ». Dans Encyclopedia of Planetary Landforms, 1–4. New York, NY : Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4614-9213-9_633-1.

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Csanády, Etele, et Endre Magoss. « Surface Roughness ». Dans Mechanics of Wood Machining, 211–75. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-51481-5_8.

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Csanády, Etele, et Endre Magoss. « Surface Roughness ». Dans Mechanics of Wood Machining, 167–94. Berlin, Heidelberg : Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-29955-1_8.

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Pont, S. C. « Surface Roughness ». Dans Computer Vision, 781–82. Boston, MA : Springer US, 2014. http://dx.doi.org/10.1007/978-0-387-31439-6_539.

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Pont, S. C. « Surface Roughness ». Dans Computer Vision, 1225–26. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63416-2_539.

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Grohmann, Carlos H., et Henrik Hargitai. « Surface Roughness ». Dans Encyclopedia of Planetary Landforms, 2100–2103. New York, NY : Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4614-3134-3_633.

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Maradudin, A. A. « Surface Acoustic Waves on Rough Surfaces ». Dans Springer Series on Wave Phenomena, 100–128. Berlin, Heidelberg : Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-83508-7_12.

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Maradudin, A. A. « Electromagnetic Surface Excitations on Rough Surfaces ». Dans Springer Series on Wave Phenomena, 57–131. Berlin, Heidelberg : Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82715-0_5.

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Raether, Heinz. « Surface plasmons on surfaces of small roughness ». Dans Springer Tracts in Modern Physics, 40–57. Berlin, Heidelberg : Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/bfb0048320.

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Farr, Thomas. « Land Surface Roughness ». Dans Encyclopedia of Remote Sensing, 311–14. New York, NY : Springer New York, 2014. http://dx.doi.org/10.1007/978-0-387-36699-9_76.

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Actes de conférences sur le sujet "Surface roughne"

Yun, Yong Il, Il Young Park et Seung Jin Song. « Performance Degradation Due to Blade Surface Roughness in a Single-Stage Axial Turbine ». Dans ASME Turbo Expo 2004 : Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53094.

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Turbine blades experience significant surface degradation with service. Previous studies indicate that an order of magnitude or greater increase in roughness height is typical, and these elevated levels of surface roughness significantly influence turbine efficiency and heat transfer. This paper presents measurement and a mean line analysis of turbine efficiency reduction due to blade surface roughness. Performance tests have been conducted in a low speed, single-stage, axial flow turbine with roughened blades. Sheets of sandpaper with equivalent sandgrain roughnesses of 106 and 400 μm have been used to roughen the blades. The roughness heights correspond to foreign deposits on real turbine blades measured by Bons et al. [1]. In the transitionally rough regime (106 μm), normalized efficiency decreases by approximately 4 percent with either roughened stator or roughened rotor and 8 percent with roughness on both the stator and rotor blades. In the fully rough regime (400 μm), normalized efficiency decreases by 2 percent with roughness on the pressure side and by 6 percent with roughness on the suction side. Also, the normalized efficiency decreases by 11 percent with roughness only on stator vanes; 8 percent with roughness only on rotor blades; and 19 percent with roughness on both the stator and rotor blades.

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Saillard, M. « Scattering of Electromagnetic Surface Waves by Rough Surfaces ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.sma6.

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The localization of classical waves, like electromagnetic or acoustic ones, has been widely studied for a few years [1]. For one- or two-dimensional systems, the localization of propagating modes is theoretically predicted at any non vanishing disorder. For instance, surface plasmon polaritons (SPP), which are extended modes of flat metallic surfaces, become localized in the presence of random roughness [2,3]. Localization of SPP on rough surfaces has important contributions to surface-enhanced phenomena [2] and gives birth to the phenomenon of enhanced backscattering for shallow surfaces [3]. But it seems that no experimental confirmation exists yet [1]. To my knowledge, no direct numerical evidence of localization has neither been published, since only backscattering peaks, considered as a signature of localization, are exhibited. Thanks to the model achieved in our laboratory [4], it is now possible.

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Gu, Zu-Han, R. S. Dummer, H. M. Escamilla, E. R. Mendez, Alexei A. Maradudin, J. Q. Lu, T. Michel et M. Nieto-Vesperinas. « Interaction of Two Optical Beams At a Symmetric Random Surface ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.sma2.

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In general, the optical field scattering from a randomly rough surface can be divided into a specular or coherent component, and a diffuse or incoherent one. It is also well known that optically rough surfaces extinguish the specular component and thus produce only diffuse light. In normal circumstances, the diffuse component is a smoothly varying envelope that modulates the speckle field. However, recently it has been reported that light scattered from randomly rough surfaces with even symmetry displays a very sharp peak in the specular direction.(1-2) The width of this peak is of order 2λ/L, where L represents the length of the illuminated portion of the surface, and λ represents the wavelength of the light. It must be stressed that this peak is not due to the presence of an unscattered component, as would be the case for a weakly scattering surface; the peak is part of the diffuse component. In previous work, this effect has been termed, in reflection, specular enhancement, and in transmission, enhanced refraction. In this paper, we shall refer to this effect as the specular enhancement.

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Gaspar, S. M., R. H. Krukar, K. P. Bishop, K. C. Hickman, L. M. Milner, S. S. H. Naqvi et J. R. McNeil. « Applications of Light Scatter for Microelectronics Manufacturing ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.smc1.

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As the level of microelectronics integration increases, device design geometries decrease. For example, current state of the art fabrication lines for high performance devices (e.g. microprocessors and DRAMs) use design geometries with critical dimensions (CDs) of 0.8 μm and smaller. Further, SEMATECH's goal for 1993 is to have CDs of 0.35 μm in production capability; goals of 0.15 μm are being discussed for the late-1990s. This trend greatly reduces processing latitude in device fabrication and thus places even greater demands on materials properties and process control. For these goals to be met, there must be more diagnostics capabilities than presently exist. Optimal characteristics for diagnostics include being noncontact, nondestructive, simple, quantitative, rapid, and capable of being implemented in-situ.

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Church, E. L., et J. C. Stover. « Mueller matrix description of scattering ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.sma3.

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Scattering measurements of rough surfaces are usually made using linearly polarized light. There are four possibilities: ba = pp, sp, ps and ss, where a is the initial state of polarization and b is the final state. Such measurements may be adequate for determining the power spectral densities (PSDs) of smooth topographically rough surfaces, but they do not capture all of the information about the surface that can be obtained from polarimetric measurements.

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Church, E. L., et P. Z. Takacs. « Specification of surface finish in terms of system performance ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.sma1.

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Bawolek, E. J., et E. D. Hirleman. « Light Scattering by Sub-Half Micron Spherical Particles on Silicon and Oxide/Silicon Surfaces* ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.pd3.

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We report angle resolved light scattering characteristics of individual polystyrene spheres on silicon and on a 91.5 nm thick film of oxide on silicon. Scattering was measured as a function of polarization using a He-Ne laser at a 45 degree incident angle.

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Takacs, Peter Z., et Eugene L. Church. « Integrating Figure and Finish Measurements with Surface Profiling Instruments ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.stub3.

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Conventional figure measurement techniques are inadequate for testing aspheres for grazing incidence applications. Conventional techniques are best suited for optical components in the shape of flats, spheres, or conical surfaces of revolution, used mainly in normal incidence applications . These optics usually have their symmetry axis coincident with the local surface normal direction. Grazing incidence optics, on the other hand, are usually cylindrical, toroidal, or ellipsoidal in shape, with the symmetry axis intersection far outside the clear aperture. Such surfaces are not axisymmetric when viewed along their surface normals. They are highly anamorphic, having vastly different curvatures in the two directions parallel and perpendicular to the symmetry axis. It is extremely challenging to test these optical components during fabrication to insure that they indeed meet the specifications for figure and finish quality. It is because of the extreme difficulties involved in developing reliable tests with conventional interferometric techniques that we decided to use profiling techniques to characterize the figure and finish of synchrotron radiation (SR) optics.

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Bawolek, E. J., James B. Mohr, E. D. Hirleman et A. Majumdar. « Light Scatter from Polysilicon Surfaces and Comparison with Surface Roughness Statistics by AFM* ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.pd2.

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Optical scatter measurements from polysilicon surfaces were performed using 632.8 nm illumination at 45 degrees and 488 nm illumination at 76.8 degrees. Scatter was recorded up to 60 degrees from the specular beam. Results are compared with surface statistics derived from Atomic Force Microscopy (AFM).

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Brown, Jeff L. « Preparing Samples for Scattering Measurements - A Cleaning Study ». Dans Surface Roughness and Scattering. Washington, D.C. : Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.smc2.

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Several cleaning methods suitable for cleaning small, low scatter samples in the laboratory were compared. The motivation for this work is to determine the relative merits of various cleaning procedures for preparing samples for BRDF measurements. A procedure which consistently reduces scatter from surface contamination to a minimum is desired.

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Rapports d'organisations sur le sujet "Surface roughne"

Jo, Hyungyung, Hyeyoung Son, Mitchell Rencheck, Jared Gohl, Devin Madigan, Hugh Grennan, Matthew Giroux, Trevor Thiele-Sardina, Chelsea S. Davis et Kendra A. Erk. Mechanical Properties of Durable Pavement Marking Materials and Adhesion on Asphalt Surfaces. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317357.

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Mechanical properties of commercially available temporary pavement marking (TPM) tapes and thermoplastic materials used as permanent pavement markings (PPM) were investigated using the non-destructive Tape Drape Test and conventional mechanical testing. The impact of temperature and aging on the adhesion of TPM tapes and thermoplastic PPM applied to asphalt core surfaces with various surface roughness and treatments was determined using a modular peel fixture and shear adhesion tests. The adhesion of TPM tapes to model smooth surfaces decreased as surface temperature was increased from 0 to 40°C (32 to 104°F). For some tapes, reduced adhesion and brittle broken fracture were observed at the lowest investigated temperature of -20°C (-4°F). The adhesion of tapes applied to asphalt decreased significantly within 1 week of aging at -25°C (-13°F). Ghost markings were more likely at higher aging temperatures. For PPM thermoplastics, better adhesion to asphalt was observed for higher application temperatures and rougher surfaces. Asphalt emulsion treatments reduced the adhesion of thermoplastics and increased the likelihood of adhesive failure after 5 months of aging at -25°C (-13°F). More ductile PPM thermoplastic materials had better adhesion to both smooth and rough asphalt surfaces compared to thermoplastic materials with a more brittle mechanical response.

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Slattery, Kevin. Unsettled Topics on Surface Finishing of Metallic Powder Bed Fusion Parts in the Mobility Industry. SAE International, janvier 2021. http://dx.doi.org/10.4271/epr2021001.

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Laser and electron-beam powder bed fusion (PBF) additive manufacturing (AM) technology has transitioned from prototypes and tooling to production components in demanding fields such as medicine and aerospace. Some of these components have geometries that can only be made using AM. Initial applications either take advantage of the relatively high surface roughness of metal PBF parts, or they are in fatigue, corrosion, or flow environments where surface roughness does not impose performance penalties. To move to the next levels of performance, the surfaces of laser and electron-beam PBF components will need to be smoother than the current as-printed surfaces. This will also have to be achieve on increasingly more complex geometries without significantly increasing the cost of the final component. Unsettled Topics on Surface Finishing of Metallic Powder Bed Fusion Parts in the Mobility Industry addresses the challenges and opportunities of this technology, and what remains to be agreed upon by the industry.

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Stupakov, Gennady. Surface Roughness Impedance. Office of Scientific and Technical Information (OSTI), décembre 2000. http://dx.doi.org/10.2172/784801.

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Stupakov, Gennady. Surface Roughness Impedance. Office of Scientific and Technical Information (OSTI), décembre 2000. http://dx.doi.org/10.2172/784831.

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DeSanto, John A. Rough Surface Scattering. Fort Belvoir, VA : Defense Technical Information Center, novembre 1991. http://dx.doi.org/10.21236/ada244829.

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Stanton, Brian, William Coburn et Thomas J. Pizzillo. Armor Plate Surface Roughness Measurements. Fort Belvoir, VA : Defense Technical Information Center, avril 2005. http://dx.doi.org/10.21236/ada432918.

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Hwang, Paul A., David W. Wang, William J. Teague, Gregg A. Jacobs et Joel Wesson. Anatomy of the Ocean Surface Roughness. Fort Belvoir, VA : Defense Technical Information Center, décembre 2002. http://dx.doi.org/10.21236/ada409487.

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Blaskiewicz, Michael. Simple formula for surface roughness wakes. Office of Scientific and Technical Information (OSTI), juillet 2019. http://dx.doi.org/10.2172/1542781.

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Sharpe, Lisa M. Analytical Characterization of Bistatic Scattering from Rough Surfaces : Dependence on Surface Correlation Function. Fort Belvoir, VA : Defense Technical Information Center, juin 1992. http://dx.doi.org/10.21236/ada256525.

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Brown, Gary S. A New Composite Roughness Surface Scattering Model. Fort Belvoir, VA : Defense Technical Information Center, janvier 1992. http://dx.doi.org/10.21236/ada248891.

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