roughness measurement Articles

  • River Floodplain Maintenance-measures influencing roughness

    The maintenance of rivers and floodplains can make an important contribution to flood protection.  Waters conservation used to be understood mainly as verification of fast discharges, which was achieved through regular mowing. Furthermore, the waterways had to be navigable and accordingly required water depths had to be accomplished through maintenance measures (e.g. digging). Today, ...


    By IWA Publishing

  • A New Technique for Measuring the Roughness Profile of Rock Joints

    This technical note describes a new technique for measuring the roughness profile of rock joints or discontinuities. This new technique involves use of a laser displacement meter (LDM) and a linear variable differential transformer (LVDT). The technique improves precision and speed of the measurement. A comparison of this technique with existing methods for measuring the roughness profile is ...


    By ASTM International

  • Surface roughness vision measurement in different ambient light conditions

    Machine vision method was used to measure the surface roughness for different Φ38 mm grinding axes in different ambient light conditions. To analyse the effect of ambient light, a method based on the grey-level co-occurrence matrix was applied at the first step. Then, a new calculation method was proposed to minimise the effect of ambient light during measurement. At the calibration stage, ...


    By Inderscience Publishers

  • Geophysical applications to solid waste analysis

    Abstract: Case studies of regional landfills show that electromagnetic geophysical methods can accurately and inexpensively define boundaries and thickness of waste. Degradation of putrescible solid waste generates conductive leachate that can be imaged with a frequency-domain terrain conductivity meter. Terrain conductivity measurements can be modified through a simple algorithm based upon ...


    By Geonics Limited

  • Effect of roughness inhomogeneities on the development of the urban boundary layer

    Wind tunnel measurements over a regular array of cubes were carried out to investigate the influence of surface inhomogeneities on the development of the urban boundary layer. Two idealised cases were investigated. The first one was in terms of a strong step change in roughness from very smooth to very rough with a low turbulent approach flow and a thin approach boundary layer. For this case it ...


    By Inderscience Publishers

  • On the parameterization of the roughness length for the air-sea interface in free convection

    The roughness length at the air-sea interface during free convection (z0fc) is mainly related to the convective velocity (w*) rather than the friction velocity (u*). The parameterization of z0fc with w * 2 /g as proposed by Abdella and DAlessio in 2003 is evaluated. It is shown that their proposed formula is consistent with field measurements. In order to avoid self-correlation by using u*, a new ...


    By Springer

  • Pipe roughness calibration in water distribution systems using grey numbers

    This paper presents a procedure based on the use of grey numbers for the calibration (with uncertainty) of pipe roughness in water distribution systems. The pipe roughness uncertainty is represented through the grey number amplitude (or interval). The procedure is of a wholly general nature and can be applied for the calibration (with uncertainty) of other parameters or quantities, such as nodal ...


    By IWA Publishing

  • Experimental study on flow and ventilation behaviours over idealised urban roughness

    Flows in the urban boundary layer (UBL) are strongly affected by the inhomogeneous roughness elements at the bottom surface. In particular, in the near-ground region (roughness sublayer), the effect of the surface roughness dominates that complicates the behaviours of mean flow and turbulence and subsequently the near-wall transport processes. To safeguard the health of urban inhabitants, it is ...


    By Inderscience Publishers

  • Introducing LaserGas III SP CO – a combustion analyzer for rough environments

    NEO Monitors unveils the industry’s most compact CO combustion analyzer suitable for the most demanding environments. LaserGas III CO includes measurement of CH4, H2O and temperature in one single unit designed to reduce risk. Based on decades of experience and customer feedback, NEO Monitors has designed an Ex-d certified tunable diode laser (TDLS) analyzer. The instrument is ...


    By NEO Monitors AS

  • The Effects of Particle Shape and Surface Roughness on the Hydraulic Mean Radius of a Porous Medium Consisting of Quarried Rock

    The influence of particle shape and surface roughness on the hydraulic mean radius are investigated, and quantitative measures for each are proposed. A particle shape factor is estimated with the aid of a new mathematical approximation for the surface area of an ellipsoid. The particle surface roughness is calculated based on inferences made from surface area data previously obtained for a sample ...


    By ASTM International

  • Effects of hydrodynamically rough grassed waterways on dissolved reactive phosphorus loads coming from agricultural watersheds

    Received for publication October 5, 2007. A modified type of grassed waterway (GWW) with large hydrodynamic roughness has proven ability to reduce sediment load and surface runoff under conditions where best management practices on the delivering fields reduce sediment inputs that could otherwise damage the grass cover. It is unknown how such a GWW affects the loading of surface runoff with ...

  • Effect of bed roughness on 1-D entropy velocity distribution in open channel flow

    A theoretic-analytical formulation, based on entropy velocity profile law and classical relationships for uniform flow and friction factor, is proposed enlightening the general logarithmic relationship existing between the parameter Φ(M), defined as mean cross section velocity over maximum velocity, and the ratio water depth/bed roughness ...


    By IWA Publishing

  • Second law analysis of viscous flow through rough tubes subjected to constant heat flux

    Entropy generation for a viscous, forced convection through enhanced rough tubes subjected to constant heat flux was numerically investigated. The entropy generation and exergy destruction due to the flow friction and heat transfer was proposed to evaluate the benefits of the utilisation of different enhanced tubes. The model was based on either measurements or empirical correlations for both the ...


    By Inderscience Publishers

  • InfoWorks measures up for Cherokee County

    Untitled Document ...


    By Innovyze

  • Intro to Hydropower Part:2 Measuring head & flow

    Measuring the stream course—Anna and Joe work downstream, shooting vertical drop (head) with a sight level, and getting a rough measurement of the pipe run at the same time. Small-scale hydro is the only renewable energy source that works for you 24 hours a day, 7 days a week. In the first article in this series (HP103), I explained the basics of hydroelectric system theory, and ...

  • An Inertial Measurement Unit Application for a GPR Tracking and Positioning

    Abstract Abilities of an inertial measurement unit (IMU) for ground penetrating radar (GPR) tracking and positioning are presented at this paper. The IMU operation principle is based on calculating of the device's orientation in space via measurement of linear accelerations and angular velocities. Features of the IMU, GPS and wheel odometer are compared. Principal scheme of the IMU consisted ...


    By Transient Technologies LLC

  • Get the scoop on the newest technology for the measurement of pH

    SENTRON had its 20th birthday in April 2005 and is world wide known as the manufacturer of glass free ISFET (Ion Sensitive Field Effect Transistor) pH systems. During the 20 years we developed and manufactured not only ISFET pH sensors but also pressure sensors in our own silicon chip production facility. This facility for development and manufacturing of solid-state sensors, enables us to ...


    By Sentron Europe BV

  • Advantages of Midheight Pore Pressure Measurements in Undrained Triaxial Testing

    Most soil mechanics laboratories still prefer the use of rough end platens during triaxial testing despite an awareness that nonuniform stress conditions occur within the soil specimen. This practice may to some extent be due to a lack of awareness of the magnitude of inaccuracies which may result. This paper describes results from unconsolidated undrained triaxial compression and extension tests ...


    By ASTM International

  • A real-time control strategy for separation of highly polluted storm water based on UV–Vis online measurements – from theory to operation

    ‘Classical’ real-time control (RTC) strategies in sewer systems are based on water level and flow measurements with the goal of activation of retention volume. The control system rule of ‘clean (storm water) runoff into the receiving water – polluted runoff into the treatment plant’ has been thwarted by rough operating conditions and lack of measurements. Due to the specific boundary conditions ...


    By IWA Publishing

  • On the urban aspect of the Copenhagen dataset

    It was one of the findings from the model validation exercise during the third workshop 1994 in Mol that there was a common tendency for all models under consideration to underestimate the observed concentrations in the case of the Copenhagen dataset. It is argued here that this is due to the fact that this experiment was performed over a rough suburban surface. In such circumstances, a roughness ...


    By Inderscience Publishers

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