A = area of the rough wall Aj = jth equal subarea of the rough region, A=NA B = empirical constant for the mean velocity profile on a rough wall; Eq. (29) CA = A-weighting factor CF = overall skin friction coefficient, 1 L R L 0 cf dx1 c = speed of sound in free field cf = local skin friction coefficient, w= 1 2 0U 2 cf0 = local skin friction coefficient at a distance xle from the leading edge ...

Subsurface perforated pipes drain infiltrated stormwater runoff while attenuating the peak flow. The Manning roughness coefficient (n) was identified as a fundamental parameter for estimating in various subsurface channels. Hence, this work, performance of six-row non-staggered sand-slot pipe sample drainage is investigated experimentally laboratory flume at Universiti Sains Malaysia (USM) aime...

A sediment geoacoustic parameter estimation technique is described which compares bottom returns, measured by a calibrated monostatic sonar oriented within 15 degrees of vertical and having a 10 degree-21 degree beamwidth, with an echo envelope model based on high-frequency (10-100 kHz) incoherent backscatter theory and sediment properties such as: mean grain size, strength, and exponent of the...

By considering the urbanization process on an overland plane whereby a relatively rough permeable surface is replaced by a relatively smooth impermeable surface, the effect of urbanization on the time of concentration is assessed. In the assessment, two opposing urbanization sequences are considered: one from downstream to upstream, and the other from upstream to downstream. The assessment is c...

It is well known that unsupervised classification of a single polarized SAR image is accomplished mainly by two steps i.e., (i) Clustering the SAR image into groups or clusters on the basis of backscattering coefficient and textures present in SAR image, and (ii) Labeling the various clusters in their respective class (For example, land cover types such as water, urban, agriculture or any other...

This paper presents a remote sensing technique for calibrating hydrodynamics models, which is particularly useful when access to the riverbed for a direct measure of flow variables may be precluded. The proposed technique uses terrestrial photography and automatic pattern recognition analysis together with digital mapping and does not require image ortho-rectification. Compared to others invasi...

Knowing loss coefficients of duct fittings is crucial for designing a duct network for HVAC systems. Traditionally, the coefficients have been obtained using experimental measurements according to AHSRAE Standard 120, a process which is time consuming and expensive. An alternative is to use CFD, but this has uncertainty due to the approximations used in modeling turbulence. This study first val...

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 fabrication of two-tier roughness structures are eliminated...

In this study, the release of gentamicin as a function of time was measured for six different gentamicin-loaded bone cements and related with the surface roughness, porosity and wettability of the cements. Initial release rates varied little between the six bone cements (CMW1, CMW3, CMW Endurance, CMW 2000, Palacos, and Palamed) and ranged from 8.6 to 14.1 microg/cm2/h. The total amounts of gen...