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Effect of surface roughness on the aerodynamic performance of turbine blade cascade

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Propulsion and Power Research 2014年第2期3卷 82-89页

作者： Tao Bain Jingyuan Liu Weihao Zhang Zhengping Zou National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics 2011 collaborated innovation center of advanced aero-engineSchool of Energy and Power EngineeringBeihang UniversityBeijing 100191China

The effect of surface roughness on the boundary development and loss behavior of turbine blades is investigated with different Reynolds numbers in this *** result shows that the velocity profile in boundary layer is plumper on rough surface than on smooth *** aerodynamic loss is lowered at low Reynolds number,but becomes significantly large at high Reynolds *** total pressure loss coefficient of cascade can reach a top increase of 129%for rougher blades comparing with smooth blades at Re=300000.

关键词： Turbine blade surface roughness Boundary layer Reynolds number Aerodynamic loss

surface roughness Detection of Precision Manufacturing for Spacecraft Instrument Using Micro-EDM

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Surface Roughness Detection of Precision Manufacturing for S...

Determining the Effect of Cutting Fluids on surface roughness in Turning AISI 1330 Alloy Steel Using Taguchi Method

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作者： Shuang Zhao Jihong Shen Chengchen Deng Jian Tai Wenjian Tao Yong Hao Ying Yang College of Automation Harbin Engineering University College of Aerospace and Civil Engineering Harbin Engineering University Qian Xuesen Laboratory of Space Technology

The demand for high attitude measuring accuracy promotes the key instrument manufacturing *** Micro-EDM manufacture technique has lots of advantages in instrument surface *** surface roughness sensing and imaging is able to provide input to *** paper designs a scheme of surface roughness *** actual experiment results show that the method presented here is able to obtain the precise image of instrument surface.

关键词： surface roughness precision manufacturing micro-EDM

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Modern Mechanical Engineering 2016年第2期6卷 51-59页

作者： Onyemachi Joachim Onuoha James Oseni Abu Sunday Albert Lawal Edeki Mudiare Michael Bolaji Adeyemi Department of Mechanical Engineering School of Engineering and Engineering Technology Federal University of Technology Minna Nigeria

Taguchi method has been employed to investigate the effects of cutting fluids on surface roughness in turning AISI 1330 alloy steel, using manually operated lathe machine. Experiments have been conducted using L27 (34) orthogonal array and each experiment was repeated three times and each test used a new cutting tool, High Speed Steel (HSS), to ensure accurate readings of the surface roughness. The statistical methods of Signal-to-Noise (S/N) ratio and the Analysis of Variance (ANOVA) were applied to investigate effects of cutting speed, feed rate and depth of cut on surface roughness under different cutting fluids. Minitab 14 software was used to analyze the effect of variables on the surface roughness. Results obtained indicated that optimal variables for the minimum surface roughness were cutting speed of 35 m/min (level 2), feed of 0.124 mm/rev (level 1), depth of cut of 0.3 mm (level 1) and a cutting fluid with a viscosity of 2.898 mm2/s (level 3). Hence, the optimal parameters to obtain better surface roughness of the workpiece material were obtained when groundnut oil based cutting fluid was used. Analysis of variance shows that feed rate has the most significant effect on surface roughness.

关键词： Taguchi Method surface roughness Turning Process Cutting Fluid

Laser Polishing of Laser Powder Bed Fusion AlSi10Mg Parts—Influence of Initial surface roughness on Achievable surface Quality

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Materials Sciences and Applications 2021年第1期12卷 15-41页

作者： Markus Hofele Andre Roth Jochen Schanz David K. Harrison Anjali K. M. De Silva Harald Riegel Aalen University Aalen Germany Glasgow Caledonian University Glasgow UK

Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing technique, which allows production of highly complex solid metal parts with good mechanical properties, compared to conventionally manufactured parts. Nevertheless, the layer-by-layer fabrication process also offers several disadvantages, including a relatively high surface roughness depending on the shape of the component, its position and orientation during the fabrication process. This paper deals with investigations on the surface roughness reduction capability, and residual surface structures by laser polishing of LPBF AlSi10Mg parts under varying initial surface roughness in order to investigate the influence of the surface behavior and initial surface roughness to the achievable surface quality by laser polishing. Hereto test specimens with varying fabrication orientations regarding to the built platform are printed and further polished. Thereby the initial arithmetic roughness varies between 19.2 μm and 8.0 μm. It could be shown that the achievable surface roughness by laser polishing with continuous and pulsed laser radiation is increasing with rising initial roughness, but the relative roughness reduction is almost constant in the range of 95% - 97.5%. The analyzation of the residual roughness structures shows, that the main roughness differences is found in the middle and long structure wavelength regime, which are directly depending on the initial surface structures of 3D printing.

关键词： Additive Manufacturing surface roughness Aluminium AlSi10Mg Laser Polishing Fabrication Orientation

Investigation on the fan-shape distribution of surface roughness on diamond-turned single crystal germanium

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Progress in Natural Science:Materials International 1996年第2期 55-62页

作者：史国权蔡永祥于骏一马文生韩荣久黄巍

The cutting force distribution models of diamond-turned single crystal germanium are established. The formation mechanisms of the fan-shape distribution of surface roughness on diamond-turned surface of single crystal germanium are investigated. The homogeneous smooth surface of roughness value Ra = 0.07 -0.009μm is obtained by fly cutting of the single crystal germanium, which was performed in the most favourable cutting direction.

关键词： single crystal germanium diamond turning surface roughness fan-shape distribution.

Effect of Different Acidic Agents on surface roughness of Feldspathic Porcelain

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Open Journal of Stomatology 2016年第3期6卷 90-95页

作者： Zeynep Yesil Duymus Alper Ozdogan Hamza Ulu Department of Prosthodontics Faculty of Dentistry Recep Tayyip Erdogan University Rize Turkey Department of Prosthodontics Faculty of Dentistry Atatürk University Erzurum Turkey

Objectives: The aim of this study was to evaluate the effect of different acidic agents on surface roughness of feldspathic porcelain. Materials and Methods: In this study, totally 60 disc shaped Noritake and Ceramco 3 feldspathic porcelain were used. The samples were divided into five groups and immersed in five acidic agents (coke, orange juice, lemonade, mineral water and black-carrot juice). After 168 hours, the specimens were evaluated surface roughness with profilometer. Results: The results showed that the highest surface roughness value (4.46 ± 2.9 μm) was identified in lemonade at Noritake porcelain and the lowest surface roughness value (1.06 ± 0.56 μm) was identified in mineral water at Ceramco 3 porcelain. The result of two-way analysis of variance test showed that there were no statistically significant differences between acidic agents on surface roughness of feldspathic porcelain (p > 0.05). Conclusions: The obtained data presented that the acidic drinks affected the surface roughness of feldspathic porcelain.

关键词： Feldspathic Porcelain surface roughness Acidic Agents

Adaptive-filter technology for detecting steel-strip surface roughness

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Baosteel Technical Research 2020年第2期14卷 1-7页

作者： TANG Wenjie GU Tingquan MOU Zhanqi Cold Rolling Mill Baoshan Iron&Steel Co.Ltd.Shanghai 201900China Research Institute Baoshan Iron&Steel Co.Ltd.Shanghai 201999China

To address the shortcomings of traditional filtering methods that utilize the scattering method for the online detection of strip surface roughness and to improve the accuracy of the identification of strip surface roughness,in this paper,a regression-smoothing adaptive-filtering method was investigated for use in the online detection of surface roughness in the cold-rolled strip. The results show that by the use of robust locally weighted regression to perform noise-reduction preprocessing of the initial parameters in the online detection of surface roughness,followed by the establishment of a kernel function,the regression-smoothing adaptive-filtering method can update the weight based on the relative positions of historical and current data. When the changes in neighboring data exceed the established threshold value of 0. 75 μm,the width of the smoothing window is automatically reduced,thereby realizing adaptive variable-step regression-smoothing filtering of online roughness detection data. By the use of this regression-smoothing adaptive-filtering method,the accuracy of detecting the surface roughness of a cold-rolled strip can be improved and the requirements of downstream users better satisfied.

关键词： surface roughness online inspection adaptive-filtering method

Relationship between Lingual Papilla surface roughness and Oral Condition in Elderly Individuals

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Open Journal of Stomatology 2021年第2期11卷 77-90页

作者： Yoko Tada Junichi Karaki Junpei Kubota Yasuaki Kakinoki Department of Special Needs and Geriatric Dentistry Kyushu Dental University Kitakyushu Japan

Objectives: Recently, an increasing number of elderly patients have complained of tongue pain and fissured tongue, while atrophy of the lingual papillae with low nutrition has also become a commonly encountered condition. The viewpoint that lingual papilla atrophy reflects systemic and pathological conditions, such as diabetes and in the circulatory system abnormalities, is supported by many clinicians. The present study was conducted to clarify the relationship of degree of atrophy of tongue papillae with oral symptoms, with an aim to evaluate the usefulness of clinical diagnostic criteria for tongue papillae atrophy. Subjects and Methods: The subjects were asked to protrude the tongue forward. The tongue was held at rest and impressions were taken of the tongue dorsum 15 mm posterior to the apex of the tongue. Surface impressions were measured using a Surfcoder SE300 and the obtained values were used to define surface roughness (Ra). Multivariate analyses of the relationships between the Ra measurements and the living environment, subjective symptoms of oral health, and survey results of measurements were performed to examine factors associated with Ra. The tongue was photographed with a digital camera, then RGB color value of four random points 15 mm from the tongue apex was determined. Using those findings, redness was calculated. Results and Conclusions: One hundred and six subjects with a mean age of 79.5 ± 9.2 years were analyzed. In the smooth group, there was more redness in the tongue dorsum as compared to the rough group. Total and Sagittal Ra values of subjects with dysphagia were lower than those without dysphagia, suggesting that the degree of oral mucosal atrophy is related to subjective symptoms of dysphagi

关键词： Lingual Papilla surface roughness Elderly Color of Tongue Papillae Atrophy

Comparative Response of CRL-11372 Cells to surface roughness and Crystalline Structure of the surfaces Developed by Sandblasting,Etching,and TiO_(2) Coating on Commercially Pure Ti Discs

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Materials Sciences and Applications 2014年第5期5卷 245-257页

作者： Sinem Yeniyol Bahadır Kepenek Ayhan Bilir Ali Fuat Cakır Nilufer Bolukbasi Mefail Yeniyol Tayfun Ozdemir Department of Oral Implantology Faculty of DentistryIstanbul UniversityIstanbulTurkey Department of Metallurgical and Materials Engineering Faculty of Chemical and Metallurgical EngineeringIstanbul Technical UniversityIstanbulTurkey Department of Histology and Embryology Faculty of MedicineIstanbul UniversityIstanbulTurkey Department of Geological Engineering Faculty of EngineeringIstanbul UniversityIstanbulTurkey

The aim of this study was to evaluate the adhesion of human fetal osteoblast cells (CRL-11372) in vitro at 24 h on commercially pure titanium (cp Ti) metal surfaces’ crystalline structure and surface roughnesses that are modified by polishing, sand blasting (with alumina (Al2O3)), sand blasting and coating (with titanium oxide (TiO2)), and sand blasting and etching (with oxalic acid). Modified surfaces were characterized quantitatively by a non-contacting optical profilometer in terms of their Rz and Ra values and surface profile diagrams were obtained. These surfaces were characterized qualitatively by scanning electron microscope (SEM) micrographs. The crystalline structures of the coatings were characterized by X-ray diffraction (XRD). CRL-11372 cells were cultured for 24 h and evaluated for their mean total cell counts. Cell morphologies were examined by SEM micrographs. Data were compared by Kruskal-Wallis test followed by Post Hoc LSD test comparisons. SEM micrographs showed variations among the topographies of the surfaces and the morphologies of the cells adhered to these four different surfaces. Cell adhesion was affected by neither Ti chemical composition nor surface roughness within the Ra and Rz parameters used.

关键词： Dental Implants surface roughness Crystalline Structure Osteoblasts Cell Adhesion