[1] Recent field and laboratory observations indicate that the variation of drag coefficient with wind speed at high winds is different from that under low-to-moderate winds. By taking the effects of wave development and sea spray into account, a parameterization of sea surface aerodynamic roughness applicable from low to extreme winds is proposed. The corresponding relationship between drag co...

OBJECTIVE The objective this work was to assess the friction coefficient between brackets and wires of different materials under conditions simulating the oral environment. MATERIAL AND METHODS Stainless steel (SS) and titanium-molybdenum alloy (TMA) wires of 0.019x0.025-in diameter (American Orthodontics) and polycarbonate bracket (American Orthodontics), ceramic bracket (American Orthodonti...

Recent evidence indicates an overall retreat from marriage. Cohabitation has contributed to this trend as cohabiting unions are increasingly not resulting in marriage. As an initial step in understanding why some cohabiting couples do not marry, we examine factors associated with cohabitors= marriage expectations. We focus particularly on the effects of socioeconomic status and race/ethnicity b...

The oxidation of stainless steels 304 and 304L during hot rolling is studied in this paper. Results show the oxide scale thickness decreases significantly with an increase of reduction, and the oxide scales of both 304 and 304L stainless steels were found more deformable than the steel substrate. Surface roughness shows a complicated transfer during the hot rolling process due to the complexity...

Savannas are among the most variable, complex and extensive biomes on Earth, supporting livestock and rural livelihoods. These water-limited ecosystems are highly sensitive to changes in both climatic conditions, and land-use/management practices. The integration of Earth Observation (EO) data into process-based land models enables monitoring ecosystems status, improving its management and cons...

A set of experiments was carried out to determine what effects periphyton communities could have on near-bed hydraulic fields. We analysed velocity distribution, skewness and kurtosis coefficients, Reynolds stresses, relative turbulence intensity, coefficient of eddy diffusivity, velocity spectra, and turbulence scales at two flows with, and without, diatom-dominated periphyton on the bed. We f...

Mechanical engineering often uses fluid lubrication to limit friction. Even in the presence of a lubricant, metallic contact between the sliding surfaces may readily occur. In running-in, the oil film thickness can be so thin that contact arises at the summit of asperities, thus, increasing both the friction coefficient and wear. Such regimes are the so-called mixed or boundary lubrication. In ...

To conduct with these land surface parameters inversion using microwave observations in the bare soil surface, it is needed to estimate soil moisture (SM), surface temperature (ST) and surface roughness changes with microwave observations. High-frequency passive microwave radiometer sensitivity of the roughness is very low, traditional ground truth can’t provide an accurate large-scale roughnes...

Frictional behavior of nano-undulated diamond-like carbon (DLC) films deposited by plasma assisted chemical vapor deposition (PACVD) process was investigated. In order to prepare the nano-undulated DLC film, a Si wafer with nano-sized Ni dots was prepared by rapid thermal annealing of Ni thin films. Since the structure of DLC film deposited by PACVD was independent of the substrate materials an...

The characteristics of fully-developed, laminar, pressure-driven, incompressible flow in rough circular microchannels are studied. A novel analytical model is developed that predicts the increase in pressure drop due to wall roughness in microtubes. The wall roughness is assumed to posses a Gaussian isotropic distribution. The present model is compared with experimental data, collected by other...