An experimental study with four different types of bed conditions was carried out to understand the effect of roughness in open channel flow at two different Reynolds numbers. The bed conditions include a smooth surface and three different roughness conditions, which were generated using sand grains with a median diameter of 2.46 mm. The three rough conditions include a surface with distributed...

In this paper we evaluate the effect of roughness and thickness of silver film substrates, fabricated on glass and polydimethylsiloxane (PDMS) templates, on surface-enhanced Raman Spectroscopy (SERS) activity. While the silver substrates obtained on glass templates exhibit nm-scale roughness, the silver substrates on PDMS templates show larger roughness, on the order of 10 s of nm. These roughn...

It is meaningful to study the surface morphology of monocrystalline material, but there are few studies on the surface roughness of quartz. So, surface roughness of Z-cut quartz etched by pure ammonium bifluoride and ammonium bifluoride mixed with isopropyl alcohol (IPA) solution was investigated for the first time in this paper. Firstly, when etching in pure ammonium bifluoride solutions, the ...

In the domain of electromagnetic wave propagation in the presence of rough surfaces, the Rayleigh roughness criterion is a widelyused means to estimate the degree of roughness of considered surface. In this paper, this Rayleigh roughness criterion is extended to the case of rough layers. Thus, it provides an interesting qualitative tool for estimating the degree of electromagnetic roughness of ...

surface roughness is one of the most important parameters that plays very critical role in determining the quality of engineering components. a good surface quality resulting in improve of fatigue strength, corrosion and wear resistance of the workpiece. on the other hand, increasing cutting speed and decreasing time of machining are desirable for manufacturers in order to reduce costs and incr...

Since commercially available profiling systems fail when determining the surface roughness of 3D additive manufactured porous structures, a novel protocol for surface roughness quantification of these porous structures has been developed based on high-resolution micro-CT images. The influence of the noise in the images and the spatial image resolution on the accuracy of the micro-CT-based rough...

A numerical simulation of micro Poiseuille flow has performed for rarefied and compressible flow at slip flow regimes. The wall roughness is simulated in two cases with triangular microelements and random micro peaks distributed on wall surfaces to study the effects of roughness shape and distribution on flow field. Two values of Mach and Knudsen numbers have used to investigate the effects of ...

In a previous study we investigated the roughness of real world textures taken from the CUReT database. We showed that people could systematically judge the subjective roughness of these textures. However, we did not determine which objective factors relate to these perceptual judgments of roughness. In the present study we take the first step in this direction using a subband decomposition of ...

Direct numerical simulation is used to investigate the transition induced by threedimensional isolated roughness elements in a supersonic boundary layer at a free stream Mach number of 3.5. Simulations are performed for two different configurations: one is a square planform roughness and the other is a diamond planform roughness. The mean-flow calculations show that the roughness induces counte...

Subjects made roughness judgments of textured surfaces made of raised elements, while holding stick-like probes or through a rigid sheath mounted on the fingertip. These rigid links, which impose vibratory coding of roughness, were compared with the finger (bare or covered with a compliant glove), using magnitude-estimation and roughness differentiation tasks. All end effectors led to an increa...