The international roughness index (IRI) for evaluating pavement surface roughness is simulated using the power spectral density (PSD) of pavement surface fluctuation. Quarter-car models recommended by the World Bank for measuring pavement roughness are adopted to simulate vehicle response. Surface roughness in time domain is generated based on 36 known PSDs of roughness. Newmark sequential inte...

Hydrophobic surfaces with microscale roughness can be rendered ultrahydrophobic by the addition of sub-micron-scale roughness. A simple yet highly effective concept of fabricating hierarchical structured surfaces using a single-step deep reactive ion etch process is proposed. Using this method the complexities generally associated with the fabrication of two-tier roughness structures are elimin...

A negative permeability in a periodic array of pairs of thin silver strips is demonstrated experimentally for two distinct samples. The effect of the strip surface roughness on negative permeability is evaluated. The first sample, Sample A, is fabricated of thinner strips with a root mean square roughness of 7 nm, while Sample B is made of thicker strips with 3-nm roughness. The real part of pe...

The transport properties of carriers in semiconducting graphene nanoribbons are studied by comparing the effects of phonon, impurity, and line-edge roughness scattering. It is found that scattering from impurities located at the surface of nanoribbons and from acoustic phonons are as important as line-edge roughness scattering. The relative importance of these scattering mechanisms varies with ...

The effect of structured roughness on the heat transfer of water flowing through minichannels was experimentally investigated in this study. The test channels were formed by two 12.7 mm wide 94.6 mm long stainless steel strips. Eight structured roughness elements were generated using a wire electrical discharge machining (EDM) process as lateral grooves of sinusoidal profile on the channel wall...

BACKGROUND Intraoral adjustment and polishing of dental ceramics often affect their surface characteristics, promoting increased roughness and consequent biofilm growth. This study correlated surface roughness to biofilm development with four commercially available ceramic materials. METHODS Four ceramic materials (Vita Enamic®, Lava™ Ultimate, Vitablocs Mark II, and Wieland Reflex®) were pre...

The aim of this study was to assess the effect of toothbrushing with toothpastes having different relative dentine abrasivity (RDA) and toothbrushes having different bristles hardness on different composite resins, compomers and traditional glassionomer cements by surface roughness evaluation. All the samples were evaluated regarding the surface roughness using roughness checker (Taylor Hobson-...

Wind erosion in agricultural soils is dependent, in part, on the aerodynamic roughness length (z0) produced by tillage ridges. Although previous studies have related z0 to ridge characteristics (ridge height (RH) and spacing (RS)), these relationships have not been tested for tillage ridges observed in the North African agricultural fields. In these regions, due to climate and soil conditions, ...

One of the surface energy balance components, the sensible heat flux, can easily be described for modelling and remote sensing purposes by means of the thermal roughness length (zot). This roughness length is usually expressed relative to the roughness length for wind speed (zou): kB−1 = ln(zou/zot). In the past, the kB−1 factor has been taken as a constant having a value of ca. 2 in the case o...

Breathiness and roughness ratings were related to a number of spectral parameters, including, among others, the relative peak level of the first harmonic, Harmonics-toNoise Ratios (HNR) in selected frequency bands, and level differences between these frequency bands. Analyses were performed for 200 ms vowel onset fragments, 200 ms mid-vowel (post-onset) fragments, and 1000 ms fragments covering...