Automatic leveling procedure by use of the spring method in measurement of three-dimensional surface roughness

Author(s):  
Syuhei Kurokawa ◽  
Yasutsune Ariura ◽  
Tatsuyuki Yamamoto
Author(s):  
Kang Liu ◽  
Titan C. Paul ◽  
Leo A. Carrilho ◽  
Jamil A. Khan

The experimental investigations were carried out of a pressurized water nuclear reactor (PWR) with enhanced surface using different concentration (0.5 and 2.0 vol%) of ZnO/DI-water based nanofluids as a coolant. The experimental setup consisted of a flow loop with a nuclear fuel rod section that was heated by electrical current. The fuel rod surfaces were termed as two-dimensional surface roughness (square transverse ribbed surface) and three-dimensional surface roughness (diamond shaped blocks). The variation in temperature of nuclear fuel rod was measured along the length of a specified section. Heat transfer coefficient was calculated by measuring heat flux and temperature differences between surface and bulk fluid. The experimental results of nanofluids were compared with the coolant as a DI-water data. The maximum heat transfer coefficient enhancement was achieved 33% at Re = 1.15 × 105 for fuel rod with three-dimensional surface roughness using 2.0 vol% nanofluids compared to DI-water.


2019 ◽  
Vol 6 (9) ◽  
pp. 190915 ◽  
Author(s):  
Hanna E. Burton ◽  
Rachael Cullinan ◽  
Kyle Jiang ◽  
Daniel M. Espino

The aim of this study was to investigate the multiscale surface roughness characteristics of coronary arteries, to aid in the development of novel biomaterials and bioinspired medical devices. Porcine left anterior descending coronary arteries were dissected ex vivo , and specimens were chemically fixed and dehydrated for testing. Surface roughness was calculated from three-dimensional reconstructed surface images obtained by optical, scanning electron and atomic force microscopy, ranging in magnification from 10× to 5500×. Circumferential surface roughness decreased with magnification, and microscopy type was found to influence surface roughness values. Longitudinal surface roughness was not affected by magnification or microscopy types within the parameters of this study. This study found that coronary arteries exhibit multiscale characteristics. It also highlights the importance of ensuring consistent microscopy parameters to provide comparable surface roughness values.


2005 ◽  
Vol 6-8 ◽  
pp. 573-582 ◽  
Author(s):  
C.M. Wichern ◽  
W. Rasp

‘Three-dimensional surface profilometry’ when used for analysis and product specification reports roughness parameters that provide an average surface description over a relatively large area. Many commercial sheet steels are produced with special textured surfaces for tribological benefits or appearance benefits. These surfaces, as well as others, may demonstrate high levels of roughness anisotropy that is not quantifiable by simple three dimensional surface parameters. This anisotropy can play an important role in the surface appearance of the finished product and in the tribological behaviour during forming. The current work presents a method for quantifying surface-roughness features as a function of angular orientation with respect to rolling direction. The measurement methodology was applied to several model surfaces and one industrially produced electron-beam textured-surface (EBT). This methodology extracts multiple surface-height profiles of the same angular orientation from a single surface and calculates an average roughness parameter for the orientation angle based on the multiple profiles. Particularly interesting results were the large number of profiles necessary to obtain repeatable values for the roughness variation with respect to direction and the strong influence of surface feature size on the repeatability of said results. These results indicate that care must be taken when using a single extracted profile to represent a ‘three-dimensional’ surface.


2014 ◽  
Vol 1017 ◽  
pp. 166-171
Author(s):  
Bin Zhao ◽  
Song Zhang ◽  
Jian Feng Li

Three-dimensional surface roughness parameters are widely applied to characterize frictional and lubricating properties, corrosion resistance, fatigue strength of surfaces. Among them, the functional parameters of surface roughness, such as Sbi, Sci, and Svi, are used to evaluate bearing and fluid retention properties of surfaces. In this study, the effects of grinding parameters, including wheel linear speed (Vs), workpiece linear speed (Vw), grinding depth (ap), longitudinal feed rate (fa), and dressing rate (F), on functional parameters were studied in grinding of cast iron. An artificial neural network (ANN) model was developed for predicting the functional parameters of three-dimensional surface roughness. The inputs of the ANN models were grinding parameters (Vs, Vw, ap, fa, F), and the output parameters of the models were functional parameters of surface roughness (Sbi, Sci, Svi). With small errors (e.g MSE = 0.09%, 0.61%, and 0.0014%. ), the ANN-based models are considered sufficiently accurate to predict functional parameters of surface roughness in grinding of cast iron.


2000 ◽  
Vol 645 ◽  
Author(s):  
Michael L. Glynn ◽  
K.T. Ramesh ◽  
P.K. Wright ◽  
K.J. Hemker

ABSTRACTThermal barrier coatings (TBCs) are known to spall as a result of the residual stresses that develop during thermal cycling. TBC's are multi-layered coatings comprised of a metallic bond coat, thermally grown oxide and the ceramic top coat, all on top of a Ni-base superalloy substrate. The development of residual stresses is related to the generation of thermal, elastic and plastic strains in each of the layers. The focus of the current study is the development of a finite element analysis (FEA) that will model the development of residual stresses in these layers. Both interfacial roughness and material parameters (e.g., modulus of elasticity, coefficient of thermal expansion and stress relaxation of the bond coat) play a significant role in the development of residual stresses. The FEA developed in this work incorporates both of these effects and will be used to study the consequence of interface roughness, as measured in SEM micrographs, and material properties, that are being measured in a parallel project, on the development of these stresses. In this paper, the effect of an idealized three-dimensional surface roughness is compared to residual stresses resulting from a grooved surface formed by revolving a sinusoidal wave about an axis of symmetry. It is shown that cylindrical and flat button models give similar results, while the 3-D model results in stresses that are significantly larger than the stresses predicted in 2-D.


2007 ◽  
Vol 8 (5) ◽  
pp. 9-17 ◽  
Author(s):  
A. Rüya Yazici ◽  
Gerard Kugel ◽  
Ali Müftü

Abstract Aim The aim of this study was to investigate the surface roughness of different types of flowable restorative resins and compare the effectiveness of diamond finishing burs followed by aluminum oxide discs with aluminum oxide discs alone in producing smooth surfaces. Methods and Materials Twenty-four specimens (10 mm X 2 mm) for each flowable resin (flowable microhybrid composite, flowable liquid microhybrid composite, flowable compomer, and flowable ormocer) were fabricated in an acrylic mold and randomly assigned to three groups. In group I samples were left undisturbed after the removal of a Mylar strip (control). In group II samples were polished with diamond finishing burs, followed by aluminum oxide discs. In group III samples were finished with only aluminum oxide discs. The mean surface roughness (Ra, μm) was determined with 3-D non-contact interferometry. Data were subjected to one way analysis of variance (ANOVA), and post hoc comparison was accomplished using Tukey's HSD. Results Although significant differences in surface roughness (Ra) values were observed among the materials using a Mylar strip (control), no significant differences between restorative materials were found when all finishing/polishing methods were combined. For all flowable restorative resins tested, the Mylar strip produced surfaces smoother than those produced by a diamond finishing bur followed by a disc or by using discs alone. Surface roughness values were statistically similar for a diamond finishing bur followed by a disc and for disc treated surfaces within each material except for Dyract Flow, a flowable compomer. Conclusion Although the surface roughness of flowable restorative resins differs among the types, this difference can be overcome with different finishing/polishing methods. Citation Yazici AR, Müftü A, Kugel G. Three-dimensional Surface Profile Analysis of Different Types of Flowable Restorative Resins Following Different Finishing Protocols. J Contemp Dent Pract 2007 July;(8)5:009-017.


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